FRONTIER DETECTORS FOR FRONTIER PHYSICS <br> 13th Pisa Meeting on Advanced Detectors <br>
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Europe/Rome
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4:00 PM
Registration
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4:00 PM
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Welcome Addresses and Opening Talk
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Status after the first LHC run: looking for new directions in the physics landscapeThe experimental data confirm that the scalar boson discovered at the LHC couples to other particles as predicted in the Standard Model, which constitutes a great success of the present theoretical paradigm. Together with the negative searches for signals of new phenomena, resulting in strong bounds on many new-physics scenarios, this opens a new perspective in fundamental physics. New ideas are needed to face the many pending questions unanswered within the Standard Model framework. Possible directions to be explored in the near future will be discussed.Speaker: Prof. Antonio Pich (Valencia University, IFIC)
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Run2 at LHCConvener: Dr Sergio Bertolucci (CERN)
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10:20 AM
Coffee break
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Run2 at LHC - Poster Session
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Improvements to ATLAS track reconstruction for Run-2Run-2 of the LHC will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which has been inserted at the centre of ATLAS during the shutdown of the LHC. We will discuss improvements to track reconstruction developed during the two year shutdown of the LHC. These include novel techniques developed to improve the performance in the dense cores of jets, optimisation for the expected conditions, and a big software campaign which lead to more than a factor of three decrease in the CPU time needed to process each recorded event.Speaker: Valentina Cairo (CS)
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The upgraded LHCb RICH detector: status and perspectivesThe LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux of beauty and charmed hadrons produced at the Large Hadron Collider (LHC). The two RICH detectors installed in LHCb have performed successfully during the 2010-2012 data taking period. The data from these detectors were essential to most of the physics results published by LHCb. In order to extend its potential for discovery and study of new phenomena it is planned to upgrade the LHCb experiment in 2018 with a 40MHz readout and a much more flexible software-based triggering system. This would increase the readout rate and occupancies for the RICH detectors. The RICH detector will require new photon detectors and modifications of the optics of the upstream RICH detector. Tests of the complete opto-electronic chain have been performed during testbeam sessions in autumn 2014. The status and perspectives of the RICH upgrade project will be presented.Speaker: Roberta Cardinale (GE)
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Performance of the ATLAS Tile CalorimeterThe Tile Calorimeter of the ATLAS experiment at the LHC is the central hadronic calorimeter designed for energy reconstruction of hadrons, jets, tau-particles and missing transverse energy. The performance of the calorimeter have been studied employing cosmic ray muons and the large sample of proton-proton collisions acquired during the run-1 of LHC (2010-2012). Results on the calorimeter performance on absolute energy scale, timing, noise and associated stabilities are presented. The results show that the Tile Calorimeter performance are within the design requirements of the detector.Speaker: Mrs Leonor Cerda Alberich (IFIC Valencia)
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First years of running for the LHCb calorimeter system and preparation for run 2The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). It comprises a calorimeter system composed of four subdetectors: a Scintillating Pad Detector (SPD) and a Pre-Shower detector (PS) in front of an electromagnetic calorimeter (ECAL) which is followed by a hadron calorimeter (HCAL). They are used to select transverse energy hadron, electron and photon candidates for the first trigger level and they provides the identification of electrons, photons and hadrons as well as the measurement of their energies and positions. The calorimeter has been pre-calibrated before its installation in the pit. The calibration techniques have been tested with data taken in 2010 and used regularly during run 1. For run 2, new calibration methods have been devised to follow and correct online the calorimeter detector response. The design and construction characteristics of the LHCb calorimeter will be recalled. Strategies for monitoring and calibration during data taking will be detailed in all aspects. Scintillating fibres, plastics and photomultipliers suffer from ageing due to radiation damage or high currents. Different methods which are used to calibrate the detectors and to recover the initial performances will be presented. The performances achieved will be illustrated in selected channels of interest for B physics.Speaker: Dr maximilien chefdeville (CNRS/IN2P3/LAPP)
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Performance of the LHCb tracking system in RunI of the LHCThe LHCb tracking system consists of a Vertex Locator around the interaction point, a tracking station with four layers of silicon strip detectors in front of the magnet, and three tracking stations, using either straw-tubes or silicon strip detectors, behind the magnet. This system allows to reconstruct charged particles with a high efficiency (typically > 95% for particles with momentum > 5 GeV) and an excellent momentum resolution (0.5% for particles with momentum < 20 GeV). The high momentum resolution results in very narrow mass peaks, leading to a very good signal-to-background ratio in such key channels as Bs -> mu mu. Furthermore an optimal decay time resolution is an essential element in the studies of time dependent CP violation. Thanks to the excellent performance of the tracking system, a decay time resolution of ~50 fs is obtained, allowing to resolve the fast B0s oscillation with a mixing frequency of 17.7 ps-1. In this talk, we will give an overview of the track reconstruction in LHCb and review its performance in Run I of the LHC. We will highlight the challenges and improvements of the track reconstruction for the data taking period from 2015 on, discussing efforts to improve the timing in the online reconstruction as well as approaches to unify the online and offline reconstruction.Speaker: Adam Davis (LHCb, University of Cincinnati)
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Commissioning of the upgraded ATLAS Pixel Detector for Run2 at LHCThe Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair modules and to ease installation of the Insertable B-Layer (IBL), a fourth layer of pixel detectors, installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. An overview of the refurbishing of the Pixel Detector and of the IBL project as well as early performance tests using cosmic rays and beam data will be presented.Speaker: Dr Daniel Dobos (CERN)
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Reconstruction performance of the ATLAS Muon detectorThe ATLAS muon reconstruction performance during the LHC run I at $\sqrt(s)= 7$ and 8 TeV was recently measured using samples of $J/\psi \rightarrow \mu\mu$, $Z \rightarrow \mu\mu$ and $\Upsilon \rightarrow \mu\mu$ decays. Reconstruction efficiency, transverse momentum resolution and momentum scales are measured in the various regions of the detector and for muon momenta between 6 and hundreds of GeV.Speaker: Dr Claudio Ferretti (University of Michigan)
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The LHCb Turbo streamThe LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the "turbo stream" the trigger will write out a compact summary of "physics" objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 with a selection of physics analyses. It is anticipated that the turbo stream will be adopted by an increasing number of analyses during the remainder of LHC Run-II (2015-2018) and ultimately in Run-III (starting in 2020) with the upgraded LHCb detector.Speaker: Dr Albert Puig (EPFL)
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Minimum Bias Trigger Scintillators for ATLAS: Commissioning and Run 2 Initial OperationsThe Minimum Bias Trigger Scintillators (MBTS) delivered the primary trigger for selecting events from low luminosity proton-proton, lead-lead and lead-proton collisions with the smallest possible bias during LHC Run 1 (2009-2013). Similarly, the MBTS will select events for the first Run 2 physics measurements, for instance charge multiplicity, proton-proton cross section, rapidity gap measurements, etc. at the unprecedented 13 TeV center of mass energy of proton-proton collisions. We will review the upgrades to the MBTS detector that have been implemented during the 2013-2014 shutdown. New scintillators have been installed to replace the radiation damaged ones, a modified optical readout scheme have been adopted to increase the light yield and an improved data acquisition chain has been used to cope with the few issues observed during Run 1 operations. Since late 2014, MBTS have been commissioned during cosmic data taking, first LHC beam splashes and single beam LHC fills. The goal is to have a fully commissioned detector ready for physics measurements during the first proton proton collisions. We will summarize the results of the ongoing commissioning; in particular we will show the timing of the triggers delivered, the data/MC calibration of the signals and preliminary studies of trigger selection performance.Speaker: Ms Mari Hoffmann (CEA Saclay)
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Overview and Present Status of the CMS Phase 1 Pixel UpgradeThe silicon pixel detector is the innermost component of the CMS tracking system, providing high precision space point measurements of charged particle trajectories. Before 2018 the instantaneous luminosity of the LHC is expected to reach about 2x10E34cm−2s−1, which will significantly increase the number of interactions per bunch crossing. To maintain a high tracking efficiency, CMS has planned to replace the current pixel system during Phase 1 by a new lightweight detector, equipped with an additional 4th layer in the barrel, and one additional forward/backward disk. A new readout chip (ROC PSI_dig) has been designed, with increased data buffers and a digital readout protocol to increase the readout speed. The present status of the project will presented, including preliminary results from tests on pre-production pixel modules and the organization and milestones for the construction of the new Pixel Tracker.Speaker: Mr Martin Lipinski (RWTH Aachen University, 1. Physikalisches Institut B)
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Lessons learned in the ATLAS IBL projectThe ATLAS experiment is ready to face the Run-2 with improved tracking performance thanks to the installation of a new Pixel layer, also called Insertable B-Layer (IBL). The IBL has been installed in May 2014 being placed at only 3.3 cm radius from the beam axis. The combination of the limited distance from the interaction point and the increase of Luminosity that LHC will face in Run-2 will require to cope both with higher radiation environment and pixel occupancy. A new readout chip has been developed within CMOS 130nm technology with larger area, smaller pixel size and faster readout capability. Dedicated design features in combination with a new composite material were considered and used in order to reduce the material budget of the support structure while keeping the optimal thermo-mechanical performance. Due to the limited radial space about less than 1 cm, the IBL detector was a challenge in terms of design and mechanical integration. An overview of the lessons learned during the IBL project will be presented, focusing on the challenges and highlighting the issues met during the production, integration, installation and commissioning phases of the detector.Speaker: Mr Antonio Miucci (University of Geneva)
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Cerenkov Detectors for Beam Quality MeasurementA new detector to measure the machine induced background at larger radii has been developed and installed in the CMS experiment at LHC. It consists of 40 modules, each comprising a quartz bar read out by a photo-multiplier. Since Cerenkov radiation is emitted in a forward cone around the charged particle trajectory, these detectors can distinguish the directions of the machine induced background. The back-end consists of a micro TCA readout with excellent time resolution. The performance of the detector modules measured in several test-beam campaigns will be reported. The installation in CMS will be described, and first results about operating the detector during data taking will be given.Speaker: Ms Styliani Orfanelli (CERN, NTUA)
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Monte Carlo simulations of the radiation environment for the CMS ExperimentFLUKA and MARS radiation transport codes are used by the Beam Radiation Instrumentation and Luminosity project (BRIL) of CMS to simulate the radiation levels due to proton-proton collisions. Results are used by the CMS collaboration for various applications: Comparison with detector hit rates, pile-up studies, predictions of radiation damage based on various models (Dose, NIEL, DPA), shielding design, estimations of residual dose environment. A description of the simulation parameters, the maintenance of the input files and key results are presented. Futhermore, an overview of additional programs developed by BRIL to meet specific to the needs of CMS community are described. These include a python based web plotting framework developed to efficiently share FLUKA results of common interest with collaborators and a method for determining the decay radiation environment during interventions, when parts of the CMS detector are brought into open configuration.Speaker: Ms Styliani Orfanelli (CERN, NTUA)
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The readiness of ATLAS Trigger-DAQ system for the second LHC runAfter its first shutdown, LHC will provide pp collisions with increased luminosity and energy. In the ATLAS experiment, the Trigger and Data Acquisition (TDAQ) system has been upgraded to deal with the increased event rates. The updated system is radically different from the previous implementation, both in terms of architecture and expected performance. The main architecture has been reshaped in order to profit from the technological progress and to maximize the flexibility and efficiency of the data selection process. The trigger system in ATLAS consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. The pre-existing two-level software filtering, known as L2 and the Event Filter, are now merged into a single process, performing incremental data collection and analysis. This design has many advantages, among which are: the radical simplification of the architecture, the flexible and automatically balanced distribution of the computing resources, the sharing of code and services on nodes. In addition, logical farm slicing, with each slice managed by a dedicated supervisor, has been dropped in favour of global management by a single farm master operating at 100 kHz. The resulting merged network, that connects the HLT processing nodes to the Readout and the storage systems has evolved to provide network connectivity as required by the new Data Flow architecture, with aggregate throughput and port density increased by an order of magnitude. Moreover, many upgrades have been implemented during this two-year shutdown in the trigger components, in order to cope with the increased trigger rates while maintaining or even improving the selectivity on relevant physics processes. This upgrade includes changes to the L1 muon and calorimeter trigger, the introduction of a new L1 topological trigger and impressive performance improvements in the HLT trigger algorithms used to identify leptons, hadrons and global event quantities, like missing transverse energy. We will discuss the design choices and the strategies employed to minimize the data-collection and the selection latency. And finally we will show the results of tests done during the commissioning phase and the operational performance after the first months of data taking.Speaker: Mr Michael Rammensee (CERN)
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ATLAS LAr Calorimeter Performance and Commissioning for LHC Run-2The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to $10^{34}~\mathrm{cm^{-2}s^{-1}}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\eta|<3.2$, and for hadronic calorimetry in the region from $|\eta|=1.5$ to $|\eta|=4.9$. In the first LHC run a total luminosity of $27~\mathrm{fb^{-1}}$ has been collected at center-of-mass energies of 7-8~TeV with very high operational efficiency of the LAr Calorimeters and excellent performance. The well calibrated and highly granular detector achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successul discovery of a Higgs boson in the di-photon decay channel. The talk will give an overview of the procedures applied to calibrate the 180.000 read-out channels electronically as well as from using reference physics signals. The data quality parameters influencing the detector resolution and their monitoring are presented. The recent detector status will be reported from the re-commissioniong of the LAr Calorimeters for the upcoming 13-14~TeV LHC Run-2, where the luminosity and the trigger rate are foreseen to be further increased.Speaker: Fabian Spettel (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D))
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Calibration Analysis Software for the ATLAS Pixel DetectorThe calibration of the Pixel detector fullfills two main purposes: to tune front-end registers for establishing the best operational settings and to measure the tuning performance through a subset of scans. An analysis framework has been set up in order to take actions on the detector given the outcome of a calibration scan (e.g. to create a mask for disabling noisy pixels). The software framework to control all aspects of the Pixel detector scans and analyses is called Calibration Console. The introduction of a new layer, equipped with new Front End-I4 Chips, required an update the Console architecture. It now handles scans and scans analyses applied toghether to chips with dierent characteristics. An overview of the newly developed Calibration Analysis Software will be presented, together with some preliminary result.Speaker: Ms Maria Elena Stramaglia (AEC-LHEP Bern University)
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Optical links for the ATLAS Pixel detectorOptical links are necessary to satisfy the high speed readout over long distances for advanced silicon detector systems. We report on the optical readout used in the newly installed central pixel layer (IBL) in the ATLAS experiment. The off detector readout employs commercial optical to analog converters, which were extensively tested for this application. Performance measurements during installation and commissioning will be shown. With the increasing instantaneous luminosity in the next years, the next layers outwards of IBL of the ATLAS Pixel detector (Layer 1 and Layer 2) will reach their bandwidth limits. A plan to increase the bandwidth by upgrading the off detector readout chain is put in place. The plan also involves new optical readout components, in particular the optical receivers, for which commercial units cannot be used and a new design has been made. The latter allows for a wider operational range in term of data frequency and light input power to match the on-detector sending units on the present pixel detector. We will report on the design and testing of prototypes of these components and the plans for the expected installation the Pixel Detector readout chain in 2015.Speaker: Ms Stefania Stucci (Bern University)
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Tracking system of the LHCb upgradeThe upgrade of the LHCb experiment will run at an instantaneous luminosity of 2x10^33 cm^-2 s^-1 with a fully software based trigger, allowing to read out the detector at a rate of 40MHz. For this purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector, withstanding the high radiation dose and providing an excellent track reconstruction with an efficiency of above 99% for all charged particles of interest. Upstream of the magnet, a silicon mico-strip detector with a high granularity and an improved acceptance coverage, called the Upstream Tracker (UT), will replace the current silicon strip tracker, and provide a rough momentum estimate. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5m long scintillating fibres read out by silicon photo-multipliers, providing a spatial resolution better than 100 micron and resulting in a total momentum resolution of 0.4% for charged particles with a momentum of 20 GeV. We will present the performance of the tracking system for the LHCb upgrade, highlighting the improvements with respect to the current tracking system of LHCb, and review the track finding strategy. Special emphasize will be put on the need for fast track reconstruction in the software trigger, also giving examples of the potential use of parallelism in the pattern recognition. Finally, we will give some prospects of the physics performance with the LHCb upgrade for channels relying on excellent tracking capabilities.Speaker: Prof. Tomasz Szumlak (AGH - University of Science and Technology)
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LHCb VELO: Performance and Radiation Damage in LHC Run 1 and Preparation for Run 2LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. Heavy hadrons are identified through their flight distance in the Vertex Locator (VELO). The VELO comprises 42 modules made of two n+-on-n 300 um thick half-disc silicon sensors with R-measuring and Phi-measuring micro-strips. In order to allow retracting the detector, the VELO is installed as two movable halves containing 21 modules each. The detectors are operated in a secondary vacuum and are cooled by a bi-phase CO2 cooling system. During data taking in LHC Run 1 the LHCb VELO has operated with an extremely high efficiency and excellent performance. The track finding efficiency is typically greater than 98%. An impact parameter resolution of less than 35 um is achieved for particles with transverse momentum greater than 1 GeV/c. An overview of all important performance parameters will be given. The VELO sensors have received a large and non-uniform radiation dose of up to 1.2 x 10^14 1 MeV neutron equivalent / cm^2 over the first LHC run. Type-inversion has been observed in regions close to the interaction point. Results of various radiation damage analyses will be presented. The preparations for LHC Run 2 are well under way and the VELO has already recorded tracks from injection line tests. The current status and plans for new operational procedures addressing the non-uniform radiation damage will be discussed.Speaker: Prof. Tomasz Szumlak (AGH - University of Science and Technology)
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Novel real-time alignment and calibration of the LHCb Detector in Run2LHCb has introduced a novel real-time detector alignment and calibration strategy for LHC Run 2. Data collected at the start of the fill will be processed in a few minutes and used to update the alignment, while the calibration constants will be evaluated for each run. This procedure will improve the quality of the online alignment. For example, the vertex locator is retracted and reinserted for stable beam collisions in each fill to be centred on the primary vertex position in the transverse plane. Consequently its position changes on a fill-by-fill basis. Critically, this new real-time alignment and calibration procedure allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. This offers the opportunity to optimise the event selection in the trigger by applying stronger constraints. The online calibration facilitates the use of hadronic particle identification using the RICH detectors at the trigger level. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger. The motivation for a real-time alignment and calibration of the LHCb detector is discussed from both the operational and physics performance points of view. Specific challenges of this novel configuration are discussed, as well as the working procedures of the framework and its performance.Speaker: Dr Mark Tobin (LPHE-EPFL)
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Performance, radiation resistance, and expectations of the Outer Tracker straw tube detector for the LHCb ExperimentThe LHCb experiment is a single arm spectrometer, designed to study CP violation in B-decays at the LHC. It is crucial to accurately and efficiently detect the charged decay particles, in the high-density particle environment of the LHC. For this, the Outer Tracker (OT) was constructed, consisting of 54,000 straw tubes, covering in total an area of 360 m2 of double layers. The detector operated in 2011/2012 under large particle rates, up to 100 kHz/cm per straw in the region closest to the beam. The performance of the OT detector during Run-I of the LHC has been studied in detail, in terms of efficiency, resolution and noise rate. Particular attention is devoted to the radiation hardness of this sensitive gaseous detector, that has shown to suffer from gain loss after mild irradiation in laboratory conditions. During the shutdown period of the LHC, extensive studies have been performed on subtle spatial alignment effects, and real-time calibration procedures have been prepared for run-II. In addition, expectations of the OT during run-II in 2015 will be shown. The increased center-of-mass energy of 13 TeV will result in larger particle densities, which is further enhanced by out-of-time hits due to the reduced bunch spacing of 25ns in run-II.Speaker: Dr Mark Tobin (LPHE-EPFL)
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DAQ Hardware and software development for the ATLAS Pixel DetectorIn 2014, the Pixel Detector of the ATLAS experiment was extended by about 12 million pixels with the installation of the Insertable B-Layer (IBL). Data-taking and tuning procedures have been implemented by employing newly designed read-out hardware, which supports the full detector bandwidth even for calibration. The hardware is supported by an embedded software stack running on the read-out boards. The same boards will be used to upgrade the read-out bandwidth for the two outermost layers of the ATLAS Pixel Barrel (54 million pixels). We present the IBL read-out hardware and the supporting software architecture used to calibrate and operate the 4-layer ATLAS Pixel detector. We discuss the technical implementations and status for data taking, validation of the DAQ system in recent cosmic ray data taking, in-situ calibrations, and results from additional tests in preparation for Run 2 at the LHC.Speakers: Clara Troncon (MI), Ms Maria Elena Stramaglia (AEC-LHEP Bern University)
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Laser calibration of the ATLAS Tile Calorimeter for LHC run-2We present in this contribution the new system for laser calibration of the ATLAS hadronic calorimeter TileCal. The laser system is a part of the three stage calibration apparatus designed to compute the calibration constants of the individual cells of TileCal. The laser system is mainly used to correct for short term (one month) drifts of the readout of the individual cells. A sub-percent accuracy in the control of the calibration constants is required to keep the systematics effects introduced by relative cell miscalibration below the irreducible systematics in determining the parameters of the reconstructed hadronic jets. To achieve this goal in the LHC run II conditions, a new laser system was designed. The architecture of the system is described with details on the new optical line used to distribute laser pulses in each individual detector module and on the new electronics used to drive the laser, to readout the system optical monitors and to interface the system with the Atlas readout, trigger, and slow control. The LaserII system has been fully integrated into the framework used for measuring calibration constants and for monitoring data quality. The Tile Unified Calibration Software (TUCS) was made ready to handle the new data format output from LaserII. First results on the laser system performances studied during its commissioning period are also presented.Speaker: Mr Marius Cornelis Van Woerden (CERN)
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CMS Tracker Performance and Readiness for LHC Run IIWe review the CMS Tracker performance during LHC Run I. We will then present the latest results of both pixel and strip detectors following the first LHC long shutdown (LS1). Results from detector calibration and commissioning, together with a description of operations and repairs done during LS1 will be shown.Speaker: Lorenzo Viliani (FI)
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Calibration and Data Quality systems of the ATLAS Tile Calorimeter during the LHC operationsThe Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It consists of thin steel plates and scintillating tiles. Wavelength shifting fibres coupled to the tiles collect the produced light and are read out by photomultiplier tubes. The calibration scheme of the Tile Calorimeter comprises Cs radioactive source, laser and charge injection systems. Each stage of the signal production of the calorimeter from scintillation light to digitization is monitored and equalized. Description of the different TileCal calibration systems as well as results on their performance in terms of calibration factors, linearity and stability will be given. The data quality procedures and data quality efficiency of the Tile Calorimeter during the LHC data-taking period are presented as well.Speaker: Mr Tibor Zenis (CU Bratislava)
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Photo Detectors and PIDConveners: Dr Eugenio Nappi (BA), Dr Karen Byrum (Argonne National Laboratory)
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CALDER: Cryogenic light detectors for neutrino and dark matter searchesLarge-mass arrays of bolometers proved to be good detectors for Neutrinoless Double Beta Decay (0ν2β) and Dark Matter searches. CUORE and LUCIFER are bolometric 0ν2β experiments which will start to take data in 2016 at Laboratori Nazionali del Gran Sasso in Italy. The sensitivity of CUORE could be increased by removing the background due to α particles, by detecting the small amount of Cherenkov light (100 eV) emitted by the βs' signal and not by αs. LUCIFER could be extended to detect also Dark Matter, provided that the background from β/γ particles (100 eV of scintillation light) is discriminated from nuclear recoils of about 10 keV energy (no light). CALDER is a new project to develop light detectors for CUORE, LUCIFER and similar bolometric experiments. The goal is to obtain detectors with an active area of 5x5 cm² (the face of bolometric crystals), operating at 10 mK, and with a baseline resolution better than 20 eV. We have chosen to develop phonon-mediated devices using superconducting MKIDs (Microwave Kinetic Inductance Detectors). We present the first results and the perspectives of the project.Speaker: Marco Vignati (ROMA1)
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Operation and performance of the ASHIPH counters at the KEDR detector.In 2014 the fully installed ASHIPH (Aerogel, SHifter, PHotomultiplier) system began its operation in the KEDR experiment at the VEPP-4M e+e- collider. The system contains 1000 liters of aerogel with refractive index 1.05 in160 counters that are arranged in two layers. Light collection is preformed by means of wavelength shifters. 160 Micro-Channel Plate PMTs with multialkali photocathode are used as photodetectors. Detection efficiency for relativistic particles was measured with е+е- -> e+e- events and cosmic muons. Detection efficiency for under-threshold particles was measured with cosmic muons. From these data pi/K-separation of 4 sigma at the momentum 1.2 GeV/c was obtained.Speaker: Mr Alexander Barnyakov (BINP, NSU)
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LHCb Upgrade: Scintillating Fibre TrackerThe LHCb detector will be upgraded during 2018/19 in order to collect data from proton-proton collisions at the LHC at higher instantaneous luminosities and to read out the data at 40\,MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with the higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will be constructed using 2.5\,m long scintillating fibres and read out by Silicon Photomultipliers (SiPM) located outside the acceptance. The fibres have a diameter of 0.25\,mm, are wound into ribbons with 5 or 6 staggered layers of fibres, and will cover a total active area of around 360\,m$^2$. State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres. A custom ASIC, the PACIFIC, will be used to digitise the signals from the SiPMs and additional front-end electronics based on FPGAs will be used to reconstruct hit positions. There are a number of challenges involved in the construction of this detector: the radiation hardness of the fibres and the SiPMs; the mechanical precision required while building large active detector components; and the cooling required to mitigate the effects of radiation damage. The evolution of the design since the Technical Design Report in 2014 and the latest R\&D results, including test beam data, will be presented.Speaker: Dr Mark Tobin (LPHE-EPFL)
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The PixFEL project: progress towards a fine pitch X-ray imaging camera for next generation FEL facilitiesThe PixFEL project, funded by INFN, is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 10^4 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 um pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. The long term goal of the PixFEL collaboration will be the development of a versatile X-ray camera to be operated either in burst mode, typical of the European X-FEL, or in continuous mode to cope with the high repetition rates of future FEL facilities.Speaker: Giuliana Rizzo (Universita' & INFN Pisa)
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An extreme high resolution Timing Counter for the MEG II experimentThe development of a Timing Counter detector with a ~30ps resolution is presented. The detector has been designed for the upgrade of the MEG experiment, looking for the μ->eγ decay with an improved sensitivity of about a factor 10 with respect to the previous MEG setup. It is based on 2 sets of scintillating pixels arranged on a semi-cylindrical structure (this shape being optimized to fit in the MEG spectrometer); each sub-detector consists of 256 counters. Each pixel is made of a 120x50x5mm3 tile of fast scintillator, with a dual-side read-out based on SiPMs arrays in series connection. The pixelated structure has 2 main advantages: - pixel sizes allow to achieve optimal resolution (~75ps) for the single module, since uncertainties in e+ path length and in scintillation light arrival time to the SiPMs are small; - a signal e+ crosses more than 1 pixel (mean number from MC is ~9) thus improving resolution by averaging the times measured by hit pixels. The pixel design has been studied using e- from a 90Sr source, comparing different scintillators, pixel sizes and SiPMs, in order to find the best devices and materials to be used. Prototype with few pixels has been built and tested both in BTF and PSI facilities in order to prove the multi-hit scheme in MEG-like beam conditions. A ~35ps resolution with 8 hits has been obtained with e+ beam @100kHz. The R&D is currently finished: the first sub-detector will be tested in the MEGII pre-engineering run planned at the end of 2015.Speaker: Matteo De Gerone (GE)
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Coffee Break
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Performances of the NA62 RICH detectorNA62 is the last generation kaon experiment at CERN. Its main goal is the measurement of the $K^+ \rightarrow \pi^+ \nu \overline{\nu}$ branching ratio with 10\% accuracy. NA62 aims to collect 100 $K^+ \rightarrow \pi^+ \nu \overline{\nu}$ events in two years of data taking. Therefore, by assuming a $10%$ signal acceptance and a $K^+ \rightarrow \pi^+ \nu \overline{\nu}$ branching ratio of $10^{-10}$, at least $10^{13}$ $K^+$ decays are required. The challenging aspect of the experiment is the suppression of decay channels with branching ratio up to 10 orders of magnitude higher than the signal and similar experimental signature, such as $K^+ \rightarrow \mu^+ \nu$. To this purpose, good PID (Particle IDentification) and kinematic rejection are required. Precise timing is also needed to correctly associate the $\pi^+$ with the parent $K^+$ in a high rate environment. The key element of the PID in NA62 is the Ring Imaging CHerenkov detector (RICH). The RICH detector is required to identify $\pi$ and $\mu$ in the momentum range between 15 and 35 GeV/c with a $\mu$ rejection factor better than $1\%$; it is also required to measure the $\pi$ arrival time with precision better than 100 ps and the Cherenkov angle with resolution better than 80 $\mu$rad. The detector consists of a 17.5 m long cylindrical vessel with a diameter varying from 3.4 to 4 m filled with neon at atmospheric pressure and room temperature. The RICH vessel was installed at CERN in February 2014 and a full vacuum test was done in March 2014. Two semispherical mirrors with 17 m focal length placed at the downstream end of the vessel reflect the Cherenkov photons. Since the area covered by the mirrors is large ($\sim$ 3 m diameter) a mosaic of 20 hexagonal segments is used. The reflected light is collected by $\sim$ 2000 photomultiplier tubes (PMTs) with 18 mm pixel size and suitable quantum efficiency and timing performances. The PMTs are assembled in a compact hexagonal packing into two aluminium disks placed at the entrance window. Winston cones carved into the disks and covered with aluminized mylar are used to convey the light onto the active PMT area, thus increasing light collection by up to $20\%$. Quartz windows are used to separate the PMTs from the neon. The mirror segments are individually hanged on a light aluminium honeycomb structure and moved by means of two piezo-motors each, in order to align the light toward the two PMTs disks. The mirrors installation and alignment was completed in August 2014. The PMT signal is sent to custom-made current amplifiers with differential output and then to NINO chips used as discriminators operating in time-over-threshold mode. The acquisition and trigger (TDAQ) system is based on an upgraded version of the LHC TELL1 board, called TEL62. The RICH will stand a rate of about 10 MHz and will be a key element of the NA62 trigger system. A three-level trigger system will reduce the 10 MHz detector rate to about 10 kHz. The level 0 (L0) is an hardware trigger which will decrease the event rate from 10 MHz to 1 MHz, employing the signals from the RICH, the photon veto system and the hadronic calorimeter. The levels 1 and 2 (L1/2) are software triggers which will reduce the rate of the events to the kHz level. At higher trigger level the RICH will provide the number and the position of the Cherenkov rings, helping to reject events with more than one ring and charged particles with $\beta=1$. At the beginning of the NA62 pilot run, from mid October to mid December 2014, the RICH detector was completely installed and ready to take data. The installation details and the preliminary results on the detector performances and on the PID system of the NA62 experiment will be presented at this conference.Speaker: Francesca Bucci (FI)
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Status of the Development of Large Area Photon Detectors based on THGEMs and Hybrid MPGD architectures for Cherenkov Imaging ApplicationsWe report about the development status of large area gaseous single photon detectors based on Thick Gaseous Electron Multipliers (THGEMs) for RICH applications. The R&D programme includes: characterization of THGEM structures of multiple active areas; study of the aspects related to single photon detection; optimization of front-end electronics; engineering towards large area detectors; evolution from triple-layer THGEM configurations to hybrid architectures comprising THGEMs and Micromegas. The most recent achievements within this R&D programme consist of the following 3 topics: First, assembly and study of hybrid photon detectors with active areas of 300 mm x 300 mm, where THGEMs act as CsI support and pre-amplification stage, and Micromegas as a multiplication stage. This configuration was successfully operated in laboratory conditions and at a CERN PS T10 test beam, achieving effective gains in the order of 10^5 and good time resolution (7 ns); Second, gain and thickness characterization of 300 mm x 600 mm single layer THGEMs; Third, investigation of the detector performance when coupled to APV25 Front-End chips, resulting in noise levels lower than 1000 electrons and single photon detection efficiencies higher than 90%. The status of the R&D programme and the recent progresses are presented, as well as prospects of future 600 mm x 600 mm active area hybrid detectors envisaging the upgrade of COMPASS RICH-1 at CERN in 2016.Speaker: C. A. Santos (INFN, Sezione di Trieste, Trieste, Italy)
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TheTORCH time-of-flight detectorThe TORCH time-of-flight detector is being developed to provide particle identification between 2-10 GeV/c momentum over a flight distance of 10m. TORCH is designed for large-area coverage, up to 30m^2, and has a DIRC-like construction with 10mm thick synthetic quartz radiator plates. Cherenkov photons propagate by total internal reflection to the plate edges and there are focussed onto position-sensitive micro-channel plate (MCP) detectors. The goal is to achieve a 15 ps time-of-flight resolution per incident particle by combining arrival times from multiple photons. A four-year R&D programme is now underway with an industrial partner (Photek, UK) to produce a 53x53 mm square MCP-PMT detector for TORCH application. The MCP-PMT will provide a spatial resolution of 0.4 mm and 6 mm in the two dimensions by incorporating a novel charge-sharing technique. The MCP-PMT will provide a timing accuracy of 40 ps and it will have a lifetime of up to at least 5 C/cm^2 of integrated anode charge by utilizing an Atomic Layer Deposition (ALD) coating. A novel method of coupling the MCP-PMT output pads to a PCB through an Anisotropic Conductive Film (ACF) will be described, together with customised readout electronics incorporating the NINO chipset. The overall requirements of the photon detectors will be presented and laboratory results on prototype MCPs will be compared with simulation. The construction of a prototype TORCH detector and its expected performance will also be described.Speaker: Prof. Neville Harnew (University of Oxford)
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Particle identification with the TOP and AEROGEL detectors at Belle-IIThe SuperKEKB e+e- collider will provide 40 times higher instantaneous luminosity than the KEKB collider. The Belle-II detector, located at the collision point, is the upgrade of the Belle detector. The particle identification in the barrel region will be improved by replacing the aerogel counter with a new high performance detector named time-of-propagagation (“TOP”). The TOP sub-detector consists of 16 quartz radiator bars and 512 micro-channel-plate photomultiplier tubes (“MCP-PMTs”). The Cherenkov photons are produced and collected at the same time in the quartz radiator, after multiple internal reflections they are detected by the MCP-PMTs. Photons with different Cherenkov angles reach different PMT channels and arrive at different time. The time and the position convolution is used for the reconstruction of the Cherenkov angle. The key features of the TOP counter, the performance study and the construction progress are presented.Speaker: Ezio Torassa (INFN Padova)
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Photo Detectors and PID - Poster Session
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Light induced tunnel effect in CNT-Si photodiodeNegative differential resistance (NDR), the current is a decreasing function of the voltage, has been observed in the current-voltage curves of several types of structures. We measured tunnelling current and NDR by illuminating large area heterojunction obtained by growing Multi Wall Carbon Nanotubes on the surface of n-doped Silicon substrate. In the absence of light, the current flow is null until a junction threshold of 2.4 V, beyond which the dark current flows at room temperature with a very low intensity of few nanoampere. When illuminated, a significant current of tens or hundreds nanoampere is observed, depending from light wavelength and intensity, at a drain voltage of about 1.5 V. At higher voltage the current intensity decreases according a negative resistance of the order of tens Mohm. In this talk we report details of tunnelling photodiode realized and negative resistance characteristics.Speaker: Carla Aramo (NA)
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On the operation of silicon photomultipliers at temperatures of 1-4 kelvinSilicon PhotoMultipliers (SiPMs) are being considered as possible photodetectors operating at low temperatures for direct dark matter searches, neutrino detectors, telescopes in space, or at high energy beams. When operating SiPMs or other solid-state devices for photon detection at liquid helium temperature, i.e. 4 kelvin, not only the electronic properties of Si can change, such as charge carrier mobility, carrier density, and electrical conductivity, but also fundamental detector properties such as absorption length for photons, quantum efficiency, time response, and noise. Some devices fail to operate at cryogenic temperatures because of their lost ability to quench pixel discharges, others exhibit a non-tolerable increase in after-pulsing probability because of carrier trapping. We have tested different types of SiPMs at 4 kelvin and were able to operate one particular type after modifications. No after-pulses were seen and single-photon detection was possible. The device was fully characterized in this temperature range. We are developing a charged particle detector immersed in the mixed He-3/He-4 liquid helium of a dilution refrigerator in which the SiPM devices must be operated at temperatures between 1 and 4 kelvin.Speaker: Dr Patrick Achenbach (Nuclear Physics Institute, Mainz University)
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Radiation hardness study of the Philips Digital Photon Counter with 800 MeV/c protonsThe Philips Digital Photon Counter (DPC) is considered as a possible photon sensor in RICH detector for Forward spectrometer of PANDA experiment at FAIR. Known issue of Geiger-mode APD is its radiation ageing. Two DPC tiles were tested using 800 MeV/c protons. Increase of dark counting rate with proton fluence up to 4*10^11 cm^-2 has been measured as well as a probability of single event effects. The dependencies of dark counting rate on the temperature before and after irradiation have been compared.Speaker: Mr Mikhail Barnyakov (Budker Institute of Nuclear Physics)
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Gain Compensation Technique by Bias Correction in Arrays of Silicon Photomultipliers Using Fully Differential Fast ShaperProposed algorithm compensates the gain by changing the bias voltage of Silicon Photomultipliers (SiPM). The signal from SiPM is amplified in fully differential preamplifier then is formed in time by the fully differential fast shaper. The compensation method was tested with four channels common cathode multi-pixel photon counter from Hamamatsu. The measurement system requires only one high voltage power supply. The polarization voltage is adjusted individually in each channel indirectly by tuning the output common mode voltage (VOCM) of fully differential amplifier. The changes of VOCM affect the input voltage through the feedback network. Actual gain of the SiPM is calculated by measuring the mean amplitude of the signal resulting from detection of single photoelectron. The VOCM is adjusted by DAC so as to reach the desired value of gain by each channel individually. The advantage of the algorithm is the possibility to set the bias of each SiPM in the array independently so they all could operate in very similar conditions (have similar gain and dark count rate). The algorithm can compensate the variations of gain of SiPM by using thermally generated pulses. There is no need to use additional current to voltage conversion which could introduce additional noises.Speaker: Mr Mateusz Baszczyk (AGH University of Science and Technology)
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Results on diamond timing detector for the TOTEM experimentWe describe the results and status of our R\&D on timing detectors for the TOTEM Collaboration. Physics program of the TOTEM experiment will require precise time of flight detectors with a resolution better than $50~ps$, to be installed in the TOTEM Vertical Roman Pots (RPs). To achieve such result we exploited ultra pure sCVD diamond technology, which provides fast, low noise and radiation hard devices. Moreover, since each RP can host 4 diamond detection plane, timing constraints are relaxed by a factor 2. On the other side diamond output signal from $8~TeV$ proton is very low ($\sim2fC/particle$) and extreme care must thus be placed on the development of dedicated front-end electronic.\\\\ Test-beams performed so far will be presented, describing set-ups and results obtained. At first off-the-shelf devices were used but unsatisfactory results push us to design a new detector. The front-end electronics, one of the critical point of the design, will be presented and discussed. Different offline analysis techniques indicate how different processing algorithm will affect detector resolution. Digitization of the signal with a fast sampler has already been tested. Together with timing performance also detector efficiency has been studied during the latest test-beams. Very satisfactory results have been obtained, both for timing and efficiency.Speaker: Mr Edoardo Bossini (university of Siena-INFN Pisa)
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Development of a low-cost fast-timing MCP photodetectorMicrochannel plate (MCP) based photodetectors feature fast timing, good position resolution and a compact form factor. We report detailed design, fabrication and characterization of a low-cost 6 cm x 6 cm fast timing photodetector based on microchannel plates. The whole assembly is made of low cost glass materials and hermetically sealed with bialkali photocathode in vacuum. A prototype MCP-photodetector exhibits gain over 10^7 level with good uniformity and photocathode quantum efficiency as high as 20%. The timing resolution reaches 20 ps and 70 ps at multi-PE and single-PE measurements, respectively. The spatial resolution reaches 0.5 mm at multi-PE measurement. Challenges and future improvements will also be presented and discussed.Speaker: Dr Karen Byrum (Argonne National Laboratory)
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The VSiPMT - A new generation of photodetectorsVSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an innovative design we propose for a revolutionary hybrid photon detector. The idea is to replace the classical dynode chain of a PMT with a SiPM, which therefore acts as an electron detector and amplifier. The aim is to match the large sensitive area of a photocathode with the performances of the SiPM technology. The VSiPMT will have many attractive features such as low power consumption, weak sensitivity to magnetic fields, excellent photon counting capability and so on. We first studied the feasibility of this detector both from theoretical and experimental point of view, by implementing a Geant4-based simulation and studying the response of a special non-windowed MPPC by Hamamatsu with an electron beam. Thanks to this result Hamamatsu realized two VSiPMT industrial prototypes. We now present the results of a full characterization of the VSiPMT prototype and the preliminary study we are performing to realize a 2-inches and 3-inches VSiPMT prototype .Speaker: Riccardo De Asmundis (NA)
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Exploring the limits of hybrid pixel detectors with MÖNCHTMÖNCH is a novel hybrid silicon pixel detector based on charge integration and analog readout featuring a challengingly small pixel size of 25x25 μm2, aimed at exploring the limits of current hybrid silicon detector technology. Two prototypes have been designed and produced in UMC 110nm technology. MOENCH02 is a fully functional prototype of 4x4mm2, containing an array of 160x160 pixels. This array is subdivided in five sub blocks, each featuring a different pixel architecture. The first block targets high resolution, low flux synchrotron applications, as RIXS (resonant inelastic X-ray scattering) or X-ray tomography with X-ray tubes. In this case the charge sharing effect between pixels, together with the signal analog readout, can be exploited to interpolate the hit position with a precision that can reach the sub-μm resolution. MÖNCH03 has an active area of 10x10mm2 and it contains an array of 400x400 identical pixels, based on the first block of MÖNCH02. It will be read out with a frame rate of ~8 kHz. The high bump-bonding yield and the extremely good noise performance of ~35 e- make hybrid detectors competitive with monolithic detectors and with CCDs in the fields of high resolution imaging and soft X-ray detection (several hundreds of eV). Characterization results in terms of bump-bonding yield, linearity, dynamic range, noise and energy resolution will be shown.The development of large area systems based on MÖNCH targeted to specific applications will also be discussed.Speaker: Dr Roberto Dinapoli (Paul Scherrer Institut)
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The kaon identification system in the NA62 experiment at CERN SPSThe CERN experiment NA62 is dedicated to the study of ultra-rare decays of the K+ in the pursuit of physics effects beyond the standard model (SM). The flagship decay K+ → π+νν has a branching fraction (BF) predicted by the SM to be (7.81 ± 0.75 ± 0.29 )×10-11and the collaboration will identify more than 100 such decays during data-taking in 2015-17 to enable a measurement of the BF to better than 10%. The necessary high number of K+ decays is obtained by exploiting an unseparated monochromatic (75 GeV/c) beam of charged particles of flux 800 MHz, of which 50 MHz are K+. Kaons are identified with more than 95% efficiency, a time resolution of better than 100 ps, and misidentification of less than 10-4 using KTAG, a differential Cherenkov detector that makes use of the gas volume and optics of a CERN CEDAR counter. KTAG utilises 8 sets of 48 Hamamatsu PMTs, of which 32 (16) are of type 9880 (7400), with signals fed directly to the differential inputs of NINO front-end boards and thence to TDC boards within the TEL62 system. Leading and trailing edges of the discriminated signal are digitised, enabling slewing corrections to be made, and a mean hit rate of 5 MHz per PMT is supported. The electronics is housed within a cooled and insulated Faraday cage with environmental monitoring capabilities. During a pilot run in autumn 2014 KTAG met its design specification.Speaker: Dr John R Fry (University of Liverpool)
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Behaviour of multi-anode photomultipliers in magnetic fields for the LHCb RICH upgradeA key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is inside the detector vacuum. The baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. The MaPMTs will be located in the fringe field of the LHCb dipole magnet with residual fields up to 25 G. Therefore, their behaviour in magnetic fields is critical. Here we report about studies of the Hamamatsu models R11265 and H12700 in a magnetic field in an effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Measurements of the collection efficiency and gain were performed for all three space directions as a function of the magnetic field strength. In addition to measurements with bare tubes, measurements with different mu-metal shielding configurations were performed to optimize the configuration. This is important input for the layout of the upgraded LHCb RICH detector.Speaker: Dr Silvia Gambett (University of Edinburgh)
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Optimization of Statistical Methods for HpGe Gamma-ray Spectrometer Used in Wide Count Rate RangesThe need to perform gamma-ray spectroscopy measurements with HpGe detectors is a common technique in many fields as nuclear physics, radiochemistry, nuclear medicine and neutron activation analysis. In other applications wide dynamic ranges in count rate may be encountered, for example samples taken after a nuclear accident are counted on a system normally used for environmental monitoring. The use of HpGe detectors is chosen in situations where isotope identification is needed because of their excellent resolution. Our challenge is to obtain the “best” spectroscopy data possible in every measurement situation. “Best” is a combination of statistical (number of counts) and spectral quality (peak, width and position) considerations over a wide range of counting rates. We present the efforts that have been done in order to optimize the statistical methods applied to HpGe detector outputs with the aim to evaluate to a better order of precision the detector efficiency, the absolute measured activity and the spectra background. Reaching a more precise knowledge of statistical and systematic uncertainties for the measured physical observables is the final goal of this research project. Use of Bayesian methods to incorporate the model uncertainty into the data analysis and the uncertainty budget could be a formidable task, which can be tackled only by exploiting appropriate numerical procedures and advances in computing technology. Moreover, when no single model stands out, the expression of the uncertainty makes necessary to report a set of models along with their probabilities, the probabilistic framework to simultaneously treat both the model and data uncertainty being given by the Bayesian model selection and model averaging. In this framework, we applied Bayesian methods and the Ellipsoidal Nested Sampling (a multidimensional integration technique) to HpGe detectors spectra. In treating these counting experiments, the prior information suggests to model the likelihood function, or probability of the data, with a product of Poisson distributions. In this paper, we shall study two different models, i.e. "Lorentzian + offset" and "Gaussian + offset", in order two explain the experimental data and compare the evidence corresponding to each model.Speaker: Dr Gianpiero Gervino (Dipartimento di Fisica and INFN Torino)
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Development and characterization of a Schottky CdTe Medipix3RX hybrid photon counting detector with spatial and energy resolving capabilitiesA multichip CdTe-Medipix3RX [1] MERLIN [2] detector system was developed in order to bring the advantages of photon-counting detectors to applications in the hard X-ray range of energies. The detector head consisted of a 2 x 2 Medipix3RX bump-bonded to a 28 mm x 28 mm monolithic pixel array electron collection Schottky ¬contact CdTe sensor. Schottky CdTe sensors undergo polarization, which increases with temperature, flux and the longer the HV is applied. To minimize polarization, the detector was water cooled and periodically the HV bias was refreshed. Results of the optimization of these parameters and evaluation of the image quality will be presented. Additionally, tests on beam line I15 at Diamond Light Source were used to evaluate the energy and imaging resolution, and the suitability of the detector for hard X-rays applications. The results of a powder diffraction experiment showing the diffraction pattern and its good consistency with the simulated data will be discussed. Furthermore, the detector was configured with 110 μm pixel pitch to make use of the Color Mode readout functionality of the Medipix3RX, where eight energy windows can be defined enabling simultaneous acquisition of both spatial and energy information. Results of the detector energy resolution and applications of the Color Mode feature will also be presented.Speaker: Dr Eva Gimenez (Diamond Light Source)
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Barrel time-of-flight detector for the PANDA experiment at FAIRThe barrel time-of-flight detector for the PANDA experiment at FAIR in Darmstadt is planned as a Scintillator Tile Hodoscope (SciTil) composed of several thousand plastic scintillator tiles, covering a total area of about 5 m^2 and readout by Silicon Photomultipliers (SiPMs). The system will be needed to identify the time origin of tracks to avoid event mixing at high collision rates with Navg = 20 MHz. It will also provide accurate relative time-of-flight measurements and benefits to the overall particle identification. The main requirements for the system are a time resolution better than 100 ps and minimum use of material. We present the latest results of various studies towards the finalization of the SciTil detector, including basic detector characterization and prototype tests. As photodetectors we consider conventional analog SiPMs as well as the Digital Photon Counter (DPC), recently invented by Philips as the first fully digital SiPM. To prove feasibility, a prototype SciTil detector has been tested in a 2.7 GeV/c proton test beam. A time resolution of about 80 ps has been achieved using SiPMs from Hamamatsu and KETEK with a sensitive area of 3 × 3 mm^2. Employing the DPC from Philips, a time resolution of about 35 ps could be measured. The tests represent one of the first studies investigating the applicability of the DPC for a large scale experiment in the field of high energy physics and show the high potential of this new detector technology.Speaker: Dr Lukas Gruber (Stefan Meyer Institute for Subatomic Physics and GSI Helmholtz Centre for Heavy Ion Research)
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Effects of very high radiation on SiPMsDuring the last 5 years we have successfully completed the R&D for instrumentation of SiPMs for the CMS HCAL Phase 1 upgrade in 2018. Much focus was put on radiation damage during these years of R&D. For the HCAL we expect a maximum total dose of 1012 n/cm2 for an total lifetime integrated luminosity of 3000 fb-1. Good correlation between cell size and performance with high radiation was found during this R&D. To evaluate the possibility of using the SiPMs in the wider CMS environment we have exposed the current state of the art smallest cell SiPMs to radiation of 1.3 1014 p/cm2 in the CERN PS 23 GeV proton beam in late 2014. In addition we are developing even smaller cell SiPMs ( < 5x5 micron cells ) together with FBK-IRST (Italy). Here we report on the effects of noise and breakdown voltage shift due to the extreme high dose. We also report on the first results on spectral response and PDE for different layouts of these newly developed ultra small cell SiPMs.Speakers: Mr Adriaan Heering (University of Notre Dame (US)), Dr Yuri Musienko (University of Notre Dame (US))
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Development of solar blind UV extended APD for readout of Barium Floride crystalsBarium fluoride crystals are the current choice for the calorimeter of the Mu2e experiment at Fermilab. By the fast (decay time 0.9 ns) 220 nm scintillation component and discriminating against the larger slow (decay time 650ns) 300 nm component, it is possible to build a radiation-hard calorimeter with good energy and time resolution and high rate capability. This requires a solid state photosensor with high quantum efficiency at 220 nm, discrimination against the 300 nm component and good rise and decay times. Progress on the development of such a sensor will be discussed.Speaker: Prof. David Hitlin (Caltech)
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Parameters of the preproduction series SiPMs for the CMS HCAL Phase I UpgradeThe CMS Barrel (HB) and Endcap (HE) Hadron Calorimeters are scintillator sampling calorimeters with embedded wavelength shifting fibers (WLS) in scintillator tiles. The fibers from the sampling layers are ganged together to form towers whose light is currently detected by HPDs. In 2012 the HCAL SiPM photo sensor upgrade was approved for the increased luminosity (5*1034) of SLHC. A key aspect of the upgrade to SiPMs is to add longitudinal segmentation to improve background rejection, energy resolution and scintillator radiation damage compensation. The SiPMs have to operate in a very hostile SLHC radiation environment (1012 n/cm2 ). To ensure good mechanical alignment and handling of large number of production channels (>20 000) we have developed a custom ceramic package. Each package holds 8 channels of SiPMs. Two candidates HPK and KETEK have developed custom large dynamic range SiPMs with large PDE and small ENC for this CMS HCAL Upgrade project. These manufactures produced a preproduction series of 175 Arrays each. Here we report and compare the final SiPM parameters of the 2014 preproduction run including the results of 1400 SiPMs per manufacturer. An overview of our QA results and our measurements of the photon detection efficiency, spectral response, cell recovery time, as well as the results on the radiation hardness will be presented.Speaker: Mr Adriaan Heering (University of Notre Dame (US))
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Impact of polishing on the light scattering on aerogel surface.Particle identification power of modern developed aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing can not be described by standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for Focusing Aerogel RICH detectors.Speaker: Dr Evgeniy Kravchenko (Budker INP)
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Characterization of SiPMs for cryogenic applicationsThe development of liquefied noble gas-based detectors is mandatory for experiments dedicated to study physics beyond the Standard Model. For this purpose, it is fundamental to provide a mean to detect the Vacuum Ultra Violet (VUV) scintillation light, produced after the passage of ionizing particles inside the detector sensitive volume, which is used for trigger, timing and calorimetry purposes. Besides the traditional cryogenic Photo-Multiplier Tubes (PMTs), one possibility is to adopt Silicon Photo-Multipliers (SiPMs). We present a comparison of the performance of several SiPM models at various cryogenic temperatures, from 60 K up to room temperature, with particular emphasis on the LAr, LN2 and LXe temperatures. SiPMs were characterized in terms of breakdown voltage, gain, pulse shape response, dark count rate and correlated noise. The experimental set-up relied on a laser source at 405 nm hitting the SiPM under test, which was hosted on a custom cold finger with adjustable temperature inserted inside a vacuum chamber. Results will be used to provide a reliable solution for a cryogenic SiPM to be adopted in the next generation of liquefied noble gas-based detectors.Speaker: Massimo Rossella (PV)
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Electron source uniformly distributed in the plane for MCP electron scrubbing and testingIn order to realize electron scrubbing and subsequent testing for microchannel plate (MCP) , several electron sources uniformly distributed in the plane are developed. The first solution is that the electron gun designed into tray shaped filament structure is installed in the proper location within the shielded metal cylinder. A metal mesh is located in the electron emitting end and a focusing electrode is laid on the front end. The performance of electron gun is adjusted by changing the filament heating current, shielding cylinder and the focusing electrode voltage. The second is using deep ultraviolet excitation gold photocathode to produce electron source uniformly distributed, wherein the light source may be a low pressure mercury lamp or a deep ultraviolet light emitting diode (DUV LED). The former is adopted by tray shaped low pressure mercury lamp, and many rotatable grids and diaphragm are orderly arranged in the outlet section. On the basis of changing the number of grid and their direction, one can adjust the intensity of ultraviolet light, which controls the beam current density. And the electron beam spot size is determined by the diaphragm diameter. The latter uses the DUV LED array as the light source, the uniformity of the beam current and the light output intensity are determined by designing the arrangement of the LED array and driving current of the LED, respectively. The third, of course, is use deep ultraviolet light directly irradiating onto the MCP input surface which is covered with Au film. By changing the DUV light intensity and the voltage of MCP, the regulation of a large range beam current is realized.Through the comparison of advantages and disadvantages of uniformly distributed electron sources with the different structures, one can obtain better production according to different use requirements. Key words: uniformly distributed electron source, deep UV light, microchannel plate, electron beam currentSpeaker: Prof. shulin liu (The Institute of High Energy Physics, Chinese Academy of Sciences)
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SPAD Array Chips with Cluster Reconstruction and Fast Full Frame ReadoutWe present two versions of single photon sensitive 2D camera chips containing 88 × 88 avalanche photo diodes. The center-of-gravity of a photon cloud can be immediately reconstructed on-chip or full image frames can be read with up to 400.000 frames per second. The sensors have imaging areas of ≈ 5×5 mm2 covered by square pixels of 56.44×56.44 μm2 with a ≈ 55% fill factor in the latest chip generation. The chips contain a self triggering logic with selectable (column) multiplicities of up to ≥ 4 hits within an adjustable coincidence time window. The photon accumulation time window is programmable as well. First prototypes have demonstrated low dark count rates of < 50 kHz/mm2 (SPAD area) at 10°C for 10% masked pixels. A FPGA based readout board has been designed to allow for intelligent on-the-fly processing of the high data rate. The device could be used in various applications where fast, spatially resolved detection of single photons is required.Speaker: Ms Ilaria Sacco (Heidelberg University)
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High granularity scintillating fiber trackers based on Silicon PhotomultiplierScintillating fibers coupled to photosensors provide flexible, fast and high granularity detectors which are able to work in a high rate environment. We will report about the performances obtained with several detector prototypes (single and multi-layers) based on 250 $\rm{\mu m}$ multi clad square scintillating fibers coupled to Hamamatsu SiPMs. Current measurements show results never reached up to now: very high detection efficiency for minimum ionizing particles already for a single layer ($\ge 95 \%$, mean collected light/fiber $\approx$ 8 phe), and full efficiency for multilayer configurations. Spatial resolutions $< 100 \; \mu m$ and $< 50 \; \mu m$ are foreseen for single layer and multilayer devices respectively. Such spatial resolutions can be achieved by keeping the optical cross-talk between fibers at a negligible level ($< 1 \%$), a level which we have proven to be obtainable when coating the fibers with aluminum. Finally, timing resolutions less than 500 ps have been achieved for m.i.p. double hit events (multilayer configuration). A comparison between the detector performances for m.i.p. and highly ionizing particle (stopped muons) will also be given, showing the possibility of particle identification based on the large difference of the energy deposit on the scintillator by the two particles.Speaker: Angela Papa (Paul Scherrer Institut)
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A new method improving multiplication factor in micro-pixel avalanche photodiodes with high pixel densityResults of simulation based on a new iterative model of avalanche process in micropixel avalanche photodiodes with low pixel capacitance (or high pixel density) are presented. The new model describes development of the avalanche process in time, taking into account change of electric field within the depleted region and the effect of parasitic capacitance shunting individual quenching micro-resistors on device parameters. Simulations show that the effective capacitance of a single pixel, which defines the multiplication factor, is the sum of the pixel thermal capacitance and a parasitic capacitance shunting its quenching micro-resistor. Conclusions obtained as a result of modelling are compared with experimental data, which demonstrate possibilities of increasing the pixel gain in micropixel avalanche photodiodes with low pixel capacitance.Speaker: Mr Azar Sadigov (National Nuclear Research Center, Baku, Azerbaijan)
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The Simulation of MCP and 20 inch MCP-PMTLarge-area MCP-PMT is an essential device for the neutrino detection experiment. The PMT requirements for this experiment are listed as follows: (1) Large size, high cathode coverage, and single PMT cathode as possible as covering its inner surface in 20 inches. (2) High detection efficiency. (3) Good single photoelectron detection capability and a large dynamic range. (4) Low radioactive background. (5) More than 20 years’ lifetime. Taking into account of this,The simulation was done by two part, one is the simulation of the MCP ,the other is the simulation of the MCP-PMT. For the high collection efficiency and high gain of the MCP, the model parameters are determined through the simulation are as follows: tha channel lengh is 410um, the diameter of the channel is 10um,the channel inclination angle is 10º, the input and out put electrode immersion depth are 5um. The simulation of two pieces of MCP is done . We adjust the distance and voltage between them, that makes the Cain of them can be 10e7,when the bise voltage is 800V. The collection efficiency can be 73,7%(the maxmum value is 80.2% ) . Yet for MCP-PMT, the effective work area of the photocathode of PMT should be large enough, the collection efficiency of MCP for the photoelectrons emitted from photocathode need be higher, and the MCP-PMT possesses smaller TTS. A 20 inches MCP-PMT which has ellipsoid structure was designed via computer simulation. The diameter of photocathode is 500mm. It includes transmission-type and reflection-type photocathode, which is able to improve its transformation efficiency. Meanwhile, we designed the best structure of the PMT whose collection efficiency is 98%, and the TTS is 17.7ns. Even considering the influence of the geomagnetic field, the collection efficiency can reach 86%Speaker: Prof. Hulin Liu (Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences)
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A new detector concept for silicon photomultipliersA novel design and principle of performance of silicon photo-multipliers are presented. The new design comprises a semiconductor substrate and an array of independent micro-photo-transistors formed on the semiconductor substrate. Each micro-photo-transistor contains a photosensitive base operating in Geiger mode and an individual micro-emitter covering a small part of the base layer, thereby creating together with the latter one a micro-transistor. The micro-transistor operates as a binary switch with on and off states due to a high value of over voltage applied to the base electrode. Both micro-emitters and photosensitive base layers are connected with two independent metal grids via their individual micro-resistors. The total value of signal gain in the proposed silicon photo-multiplier is a result of both the avalanche gain in the base layer and the corresponding gain in the micro-transistor. The main goals of the new design are: to decrease significantly both optical cross-talk at high signal amplification and the device capacitance; to improve speed of forming of single photo-electron pulses received from the micro-transistor circuit.Speaker: Mr Azar Sadigov (National Nuclear Research Center, Baku, Azerbaijan)
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Characterization of first prototype of high-density NUV-HD SiPMs for near-UV light detectionNew high-density (HD) cell silicon photomultipliers (SiPM) for near-ultraviolet light detection have been recently produced at Fondazione Bruno Kessler. The NUV-HD SiPMs are an evolution of the standard NUV technology, based on a p-on-n junction and featuring peak detection efficiency in the region between 380 and 480 nm. With respect to the standard NUV SiPMs, the HD technology implements a new border structure, based on trenches, which provide both electrical and optical isolation of the single-photon avalanche diodes. This technology has been exploited to produce devices with small cells (from 30×30 μm2 down to 12×12 μm2) increasing at the same time the fill factor (FF), equal to 77% for the bigger cell and higher than 50% for the smallest one. Thanks to the high FF, a photo-detection efficiency approaching 55% has been measured at 400 nm for the SiPM with 25×25 µm2 cell size with a dark count rate of less than 150 kHz/mm2 at maximum efficiency and 20°C. At the same time, the ability to reduce the cell size preserving FF leads to a proportional reduction of the gain and hence of after-pulsing and optical Cross-talk phenomenons, mainly due to an effective reduction of the carriers trapped as well as the photons produced during the avalanche. The direct cross-talk and the after-pulse probabilities measured at maximum efficiency are equal to 25% and 2% respectively, halved with respect to the standard NUV devices.Speaker: Dr Giovanni Paternoster (Fondazione Bruno Kessler)
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Test and characterization of SiPMs intended as detector for the MEG high resolution timing counterThe measurement system and characterization of more than 1000 SiPMs intended to be used in the MEG high resolution timing counter is presented. After a brief a description of the aim of the MEG project and the motivation of the reasons which led to the choice of the devices, the hardware measurement system is described. SiPMs will be grouped by 12 to form a single pixel of the MEG timing counter. The deiveces used in a pixel must exhibit the most uniform behavior as possible to ensure a proper time resolution. A particular C++ software algorithm has been used to extrapolate the parameters usefull for the systematic characterization of the devices, which must take into account their breakdown voltage, gain and dark count noise, to allow a uniform positioning of each SiPM. This software and its outputs are presented together with the ageing data collected after more than 100 days of a SiPM light illumination. The measurement system is intended for the characterization of more than 6000 devices.Speaker: Marcello Simonetta (PV)
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The CHarged ANTIcounter for the NA62 experiment at CERNThe NA62 experiment at CERN aims to measure with an error of 10% the decay fraction of the very rare process , studying the decay in flight of the contained in an intense secondary beam of positive particles of 75GeV / c momentum, produced using the proton beam of the CERN SPS. A particularly insidious source of background is due to events produced by the inelastic interactions of the beam with the three measurement stations - in particular the third (GTK3) - of the beam spectrometer (GTK), which are made of silicon pixel detectors. The spectrometer is installed in the vacuum at the entrance of the vacuum pipe in which is placed the fiducial decay region. A positive pion, produced in one of these events and detected by the apparatus of NA62 so that its origin is erroneously reconstructed in the fiducial region, simulates an event signal. To reject this type of background, reducing it to an acceptable level, a veto detector for charged particles - CHANTI (Charged Anti-Counter) - was designed and built using bars, with triangular cross-section, of plastic scintillator read by Silicon PhotoMultiplier (SiPM). The detector is placed in vacuum immediately after GTK3 so that, without interfering with the beam, it can intercept, with efficiency ∼1 and time resolution of ∼1 ns, traces of charged particles produced in GTK3 at angles ranging from about 50 mrad to little more than a rad, with respect to the beam direction. The front-end electronic boards allow fast amplification (25 X), individual channel fine bias setting with O(mV) resolution and 0.1% stability and current measurement for each SiPM, in order to monitor any possible degradation. The first data have been collected between October and December 2014 at CERN. The results given by the analysis of the data collected will be shown. The detector time resolution is well in line with the specifications.Speaker: Mr Marco Mirra (NA)
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Fast Timing Detector R&D for the HL-LHC eraThere is a growing interest in applying timing measurement of physics objects (leptons, jets, photons) in the high pileup environment planned for the next decade at the LHC. Time of occurrence of events within the same bunch (“in-time pileup”) can be used analogously to the more commonly used “event vertex position” tagging to resolve events of interest in this busy environment. Extending to this 2-D tool (time and space discrimination) is likely key to enabling the challenging measurements of the next decade by suppressing pileup background. Currently both ATLAS and CMS are exploring the potential of this tool for improving physics capability.Speaker: Dr Sebastian White (Princeton University)
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The Performance Test of the 20 inch PMTs for JUNOThe JUNO (Jiangmen Underground Neutrino Observatory) designed to build an underground lab on the location of JiangMen in south China as a generic underground national lab for many applications. The new promising neutrino programs request the higher performance of the detectors, especially the photo detector PMT (Photomultiplier Tube), need effectively large area, high quantum efficiency. It is proposed to increase the photoelectron detection efficiency of the PMT used in neutrino experiment. The researchers in IHEP designed a new type of MCP-PMT. The small MCP unit instead of the large Dynode, the transmission photocathode and the reflection photocathode were assembled in the same glass shell to form nearly 4π photocathode effective area to enhance the efficiency of the photoelectron detecting. Some researchers and engineers in institutes and companies in China come together to manufacture and research this type of PMT based on the MCPs. After three years R&D work, except successfully producing the 8 inch prototypes, the 20 inch one also produced at the end of 2014. The characteristics of the photocathode was carefully researched by testing the I-V curve, the QE-λ, and the QE-map for the 8/20 inch area photocathode uniformity. Also we measured the charge spectrum to confirm its ability for the single photoelectron spectrum. The detailed will be described in this formal poster.Speaker: Prof. Sen Qian (The Institute of High Energy Physics, Chinese Academy of Sciences)
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Silicon photomultipliers for DM searches with liquid argon detectorsNext generation multi-ton scale noble liquid experiments have the unique opportunity to discover dark matter particles at the TeV scale, reaching the paramount sensitivity of 10^-48 cm^2 in the WIMP nucleon scattering cross section. A prerequisite will be the reduction of radiogenic background sources to negligible levels, only possible if ultrapure high efficiency photosensors are available for the scintillation light readout. Major requirements for the next generation experiments' photosensors are: high quantum efficiency, high gain, high single photon resolution, wide linear dynamic range, fast response, large sensitive areas, low radioactivity, low power consumption and low price. An attractive solution is provided by SiPM arrays, with low intrinsic radioactive background and small mass in addition to unrivalled performances in single photon detection, enhanced in the cryogenic environment. We will report on the R&D carried out at INFN Napoli and LNGS towards the realisation of a multi-ton scale liquid argon detector with SiPM light readout.Speaker: Susan Walker (Università degli Studi di Napoli "Federico II" & INFN Napoli)
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Large size SiPm matrix for Imaging Atmospheric Cherenkov Telescopes applicationsSiPm photo detectors are nowadays commonly used in many applications. It has been shown that SiPm are "nearly ideals" light sensors for Imaging Atmospheric Cherenkov Telescopes (IACT), however this was proven only for small size telescopes. For large size telescopes like MAGIC or the future Large Size Telescope (LST) of the Cherenkov Telescope Array project (CTA), a pixel size of some cm2 is needed. An analog amplifier and sum stage was built and characterized. A large and compact SiPm matrix prototype, with the associated focusing optics, was assembled into a monolithic light detector with an active area of ~3 cm2. The performance of the electronics is tailored for IACT applications, with fast signal and adequate signal/noise ratio.Speaker: Prof. Mose Mariotti (INFN Sezione di Padova)
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Picosecond Cherenkov detectors for heavy ion experiments at LHEP/JINRA system of Cherenkov detectors with picosecond time resolution are developed for study of heavy ion collisions with beams of Nuclotron and collider NICA at LHEP/JINR, Dubna. The detectors will be applied in two large scale setups BM@N and MPD with aim of production of a start signal for TOF detector and generation of an effective L0 trigger for nucleus – nucleus collisions. The detectors are based on a quartz radiator optically coupled with MCP-PMT XP85012-A1/Q from Photonis. The detector concepts, results of MC simulation and measurements with a beam of relativistic deuterons are discussed.Speaker: Dr Vladimir Yurevich (Joint Institute for Nuclear Research)
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Round Table: Synergies and complementarity among laboratoriesConvener: Francesco Forti (PI)
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Coffee break
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Round table final remarks
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ApplicationsConveners: Prof. Juan José Vaquero (Universidad Carlos III de Madrid), Dr Ralf Hendrik Menk (Elettra Sincrotrone Trieste)
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A Compact, High Density γ-Detection Module for Time-of-Flight Measurements in PET ApplicationsWe present a very compact γ-detection module primarily designed for PET applications. On a total area of ≈ 30×30 mm2, 144 SiPM photo detectors coupled to scintillator crystals are read out individually with fast timing ASICs. The core of the module is a LTCC ceramic substrate with internal water channels for efficient and stable liquid cooling. The top side of the LTCC is covered by 12 × 12 SiPMs in a regular pitch of 2.5 mm. The SiPMs are designed in the RGB-HD technology from FBK with a single cell size of 25 × 25μm2, very low dark-count rate and stable performance over a wide temperature range from 0 to 20° C. The readout of the SiPMs is done with 4 specialized PETA5 ASICs flip-chip mounted to the bottom side of the substrate. Each chip has 36 readout channels (available in single or differential ended configuration) with self triggered hit detection, a very low noise discriminator, signal amplitude integration and digitization, a TDC with 50ps binwidth, neighbor logic and fast veto mechanisms. The full height of the assembly, including the connector to the main readout board, is less than 1 cm. In a 1:1 coupling configuration with 10 mm high LYSO scintillator arrays for detection of 511 keV gammas, the module has already reached 200 ps CRT time resolution (FWHM in coincidence between channels on two different modules), sufficient for ToF operation in PET. We present the module design, details on chip operation and latest results with LYSO arrays.Speaker: Ms Ilaria Sacco (Heidelberg University)
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First tests for in-beam carbon therapy treatment monitoring with a planar PET system at CNAOOne of the most promising new radiotherapy techniques is using charged particles like protons and carbon ions, rather than photons. At present, there are more than 50 particle therapy centers operating worldwide, and many new centers are being constructed. Positron Emission Tomography (PET) is considered a well-established technique to monitor the delivered dose to the patient particle treatments non-invasively. Nuclear interactions of the charged hadrons with the patient tissue lead to the production of beta+ emitting fragments (mainly 15O and 11C), that decay with a short lifetime producing a positron. The two 511 keV annihilation photons can be detected with a PET detector. In-beam PET is particularly interesting because it could allow to monitor the ions range. A large area dual head PET prototype was built and tested. The system is based on an upgraded version of the previously developed DoPET prototype. Each head covers now about 15x15 cm2 and is composed by 9 (3x3) independent modules. Each module consists of an H8500 PMT coupled to a 23x23 LYSO crystal matrix (2 mm pitch) and is readout by custom front-end and a FPGA based data acquisition electronics. Data taken at the CNAO treatment facility in Pavia from proton and carbon beams impinging on various phantoms will be presented with particular attention to the evaluation of the activity depth in the phantoms. The comparison of these data to the one obtained using the FLUKA Monte Carlo will be also presented.Speaker: Valeria Rosso (PI)
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An integrated system for the on-line monitoring of particle therapy treatments accuracyThe quality assurance in particle therapy is a still-open issue that can be addressed with reliable monitoring techniques of treatment accuracy. The INSIDE (INnovative SolutIons for DosimEtry in hadrontherapy) project aims at the development of an integrated on-line monitoring system based on a dedicated PET scanner and a tracking system. It is designed to operate in-beam and provide an immediate feedback on the particle range. The PET system is composed of two planar heads (10x20cm^2), placed at 25 cm from the isocenter and made of LSF pixel crystals (3x3x20mm^3) coupled one to one to MPPCs. The tracking system is composed of 6 planes of orthogonal squared scintillating fibers coupled to a 1 mm^2 SiPM combined with an electromagnetic calorimeter made of LYSO crystals coupled to Position Sensitive PMTs. Monte Carlo simulations cover an important role both in the system development, by confirming the design feasibility, and in the system operation, by understanding data. To reduce simulation time in signal generation on PET detectors, a novel FLUKA-based two-step simulation has been implemented: first the treatment beam is simulated with partial statistics, then the scored isotopes activation is used as generator for a second full-statistics step. With this technique the simulation time is reduced of about 70x. This work presents the INSIDE project and provides an up-date of the system development and simulations.Speaker: Elisa Fiorina (TO)
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Detection of thermal neutrons using ZnS(Ag):6LiF neutron scintillator readout with WLS fibres and SiPMsWe present the development of a multi-channel thermal neutron detection system for the application in neutron scattering experiments. The detection system is based on ZnS(Ag):6LiF scintillation screens which are readout with wavelength shifting (WLS) fibres and Silicon Photomultipliers (SiPMs). The use of SiPMs in scintillator-based neutron detectors promises several advantages such as a compact size of the detector and its insensitivity to magnetic fields. The long emission time of the ZnS scintillator and the deficient light collection due to the poor transparency of the scintillator make it difficult to combine a high signal detection efficiency with a reasonable suppression of the SiPM dark counts. We solve this problem by optimizing the light collection from the scintillation screens [1] and by applying a dedicated signal processing algorithm to analyze the temporal distribution of the SiPM pulses [2]. We will present the design and construction of prototype detection units and will summarize the measurements demonstrating the achievement of the requirements typical for this kind of detection systems which were so far only reached with PMT- or Multianode-PMT-based systems and which are, in particular concerning the neutron absorption probability, comparable or even higher than for certain Helium-3 filled neutron detectors. [1] J.-B.Mosset et al., Journal of Physics: Conference Series 528 (2014) 012041 [2] A.Stoykov et al., Journal of Instrumentation 9 (2014) P06015Speaker: Dr Malte Hildebrandt (Paul Scherrer Institut)
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Depleted Argon extraction for Dark Matter SearchesThe DarkSide Collaboration just completed a 7-years effort in collection and purification of underground argon depleted in the radioactive 39Ar, which pollutes atmospheric argon at the level of 1 Bq/kg. I will present the first results of the operation of the DarkSide-50 detector with underground argon. The availability of tonne-scale batches of depleted argon is a key enabling element of large scale dark matter detectors. I will present the plans of the DarkSide Collaboration for the expansion of the collection of underground argon and for the possible, further active isotopic depletion of underground argon.Speaker: Dr Cristiano Galbiati (Princeton University)
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Applications - Poster Session
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TOFPETv2: a high-performance circuit for PET Time-of-FlightWe present a readout and digitization ASIC for radiation detectors using modern Silicon Photomultipliers [1]. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current mirror based on a regulated common-gate topology. The chip has quad buffered analogue interpolation TDCs and charge integration ADCs, in each channel. The signal amplitude can also be derived from the measurement of time-over-threshold. The circuit has linear response in the range 0-1500 pC. Simulation results show that for an impulse charge of 200 (550) fC the circuit has 25 (30) dB SNR, 93 (39) ps r.m.s. time resolution, and 5 (8) mW power consumption. The maximum event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection. [1] T. Nagano, N. Hosokawa, A. Ishida, R. Tsuchiya, K. Sato, and K. Yamamoto, “Timing resolution dependence on MPPC geometry and performance,” in Proc. Conf. Rec. IEEE Nuclear Science Symp., Seoul, Korea, Oct./Nov. 2013, pp. 1–5, paper NPO1-89.Speaker: Mr Agostino Di Francesco (LIP Laboratorio de Instrumentacao e Fisica Experimental de Particulas)
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A compact muon tracking system for didactic and outreach activities.We present a cosmic ray telescope based on the use of plastic scintillator bars coupled to Advansid Silicon Photomultipliers (SiPM) through wavelength shifter fibres. The system is comprised of 200 electronic channels organised into 10 couples of orthogonal planes allowing the 3D reconstruction of crossing muons. Two monolithic PCB boards have been designed to bias and readout all the SiPMs enclosed in the system, to monitor the working parameters and to remotely connect the detector. To make easier the display of muon tracks to non expert users, two led matrices, triggered by particle interactions, have been implemented. To improve the usability of the muon telescope, a programmable logic and a USB microcontroller permit to select different levels of trigger and allow data acquisition for refined analyses for the more proficient users. A first prototype, funded by INFN-Gran Sasso National Laboratory and deployed in collaboration with New York University Abu Dhabi and Age Scientific, is operating at the Toledo Metro station of Naples, while two further detectors will be developed and installed in Abu Dhabi.Speaker: Mr Luis Pazos Clemens (NEW YORK UNIVERSITY ABU DHABI)
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CERBEROS: a Tracking System for Secondary Pion Beams at the HADES SpectrometerIn 2014 the HADES collaboration performed two successful physics production runs with secondary pion beams. Since secondary beams are strongly defocussed in position and momentum, two fast tracking stations were installed along the pion beam chicane following the pion production target providing the momentum measurement of each individual pion. The momentum is reconstructed using the position information of every hit detected by the tracking stations and the beam optics transport calculation with a resolution below 0.5% playing an important role in terms of the exclusive analysis of investigated reactions. Both stations consit of a double sided silicon strip detector with an large active area (10x10cm2). To guarantee fast tracking, the sensors are read out with the n-XYTER ASCI chip. Due to its self-triggering architecture and local storage capability, the chip enables on-line tracking at high rates (dN/dt > 106 part./s). The TRB3 on which the trigger logic is implemented integrates the system into the HADES DAQ. In this presentation we are showing the results obtained during a calibration experiment with a monochromatic proton beam set at seven different momenta centered around 2.68 GeV/c. Also the excellent system performance achieved during the production campaign with pion beams are reported about.Speaker: Joana Wirth (Physik Department E12, Technische Universität München, Graching, Germany)
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Characterization of Pr:LuAG scintillating crystals for X-ray spectroscopyThe main features of the Pr doped Lu$_3$A$_{15}$O$_{12}$ (Pr:LuAG) scintillating crystals for X-ray spectroscopy applications have been studied using different radioactive sources and photo- detectors. Pr:LuAG is cheaper, compared to a Germanium detector, but with remarkable properties which make it useful for many applications, from fundamental physics measurements to the PET imaging for medical purposes: high density, elevate light yield, fast response, high energy resolution, no hygroscopicity. A sample of Pr:LuAG crystals with 0.5" $\times$ 0.5" surface area and 13 mm thickness and a NaI crystal of the same surface and 26 mm thickness used as a reference have been characterized with several radioactive sources, emitting photons in the range 100$\div$1000 keV. Different light detectors were adopted for the Pr:LuAG studies, sensitive to its UV emission (peak at 310 nm): a 3" PMT (Hamamatsu R11065) and new arrays of Hamamatsu SiPM, with siliconic resin as a window. Results are presented on the performance of the Pr:LuAG crystals, to be mounted in a 2 $\times$ 2 array to be tested in the 2015 run of the FAMU experiment at RIKEN-RAL muon facility. The goal is the detection of the X-rays (around 130 keV) emitted during the de-excitation processes of the muonic hydrogen after the excitation with an IR laser with wavelength set at the resonance of the hyperfine splitting, to measure the muonic atom proton radius with unprecedented precision.Speaker: Massimo Rossella (PV)
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Development of a novel Micro Pattern Gaseous Detector for cosmic ray muon tomographyCosmic ray tomography consists in using particle detectors to reveal the presence of materials with high atomic number, as radioactive elements or heavy metals. Although the validity of the muon tomography has already been demonstrated, its use on a large scale is still disfavored because of the high cost and complexity of the detectors. We propose a novel detector (Thick Groove Detector, TGD) specifically designed for this application, having the potential to be easily produced on industrial scale. The proposed detector belongs to the category of MPGDs with an amplification region less than 1 mm wide. In its basic concept the TGD has a larger drift region and a thin amplification gap formed by alternate anode/cathode microstrips layers at different heights. The use of this device has several advantages: it allows for compact scanning stations (reduced transverse dimensions) and reduced operating costs (limited applied voltages and small gas volumes) when compared to other gas detectors as drift chambers and it is competitive from the point of view of the cost production. The potential for industrial mass production makes the TGD a good candidate for the homeland security market. A first 10x10 cm^2 prototype of the detector has been built, divided into four sections with different test geometry. We will illustrate the construction procedure and we will discuss first results in terms of gain and stability in comparison to the performance expected from simulations.Speaker: Fabrizio Petrucci (ROMA3)
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Experimental Verification of Beam Position and Size Determination Using Scattered Charged Particles for Real Time Quality Assurance in Proton HadrontherapyWe present the experimental verification of the Interaction Vertex Imaging technique for the reconstruction of the position and size of a proton beam for hadrontherapy. The results presented demonstrate the feasibility and attractiveness of this technique using protons scattered at large angles and emerging from the phantom, in terms of both event rate and reconstruction accuracy. The results obtained on data with 126 and 200 MeV clinical treatment proton beams agree well with the simulation predictions by a dedicated Geant4 program, providing validation for this application. The reconstruction technique, its performance and the instrumentation requirements are discussed in details, in view of a potential application to real-time quality assurance in proton hadrontherapy. The extension of this technique to hadrontherapy with carbon beams, the optimization of the detector system and the perspectives for the application of novel semiconductor pixel sensors will be discussed.Speaker: Marco BATTAGLIA (UCSC and CERN)
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Fast Neutron and Gamma-ray Detection with Liquid-Xe Detector for Contraband DetectionWe have investigated the possibility of using a liquid Xe (LXe) detector for combined imaging and spectroscopy of neutrons and gamma-rays in the MeV range. This activity is part of the R&D work on LXe detectors performed at WIS for the search of dark matter. Our aim is a detection of hidden explosives and fissile materials in cargo and containers using fast neutrons resonant transmission radiography and high energy dual discrete gamma-ray radiography. The detector consists of a fast liquid-xenon (LXe) converter-scintillator coupled to a UV-sensitive gaseous imaging photomultiplier (GPM) made of a cascaded Thick-Gas Electron Multipliers (THGEMs) of which the first one is coated with a CsI photocathode. Simulation study and experimental results of the GPM performance in combination with a LXe converter will be presented and the cryogenic experimental system for radiographic investigations with neutrons and gammas will be described.Speaker: Dr David Vartsky (Weizmann Institute of Science)
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Fast and Precise Large Area Topology Measurements Using Laser Distance SensorsNovel developments in particle detector technology require fast and precise methods to measure large area topologies in the order of a few square meters. A standard method is a tactile coordinate measurement system. With such a system resolutions of better 10 µm are achievable but with relatively long duration of several hours for one cycle. Sensitive structures may be damaged. We present a method using a non tactile laser distance sensor. Such a device is able to scan surfaces very fast without touching the surface. The presented device has a special measurement mode, enabling it to measure semitransparent surfaces. The vertical translator to mount the sensor is able to move in sub mm steps. Using this we are able to measure the position and height of copper on FR4 with an accuracy below 10 µm. This technology can be used in nearly every field where a fast topology scan of large areas is required. We report on the performance of the sensor scaning non transparent as well as semitransparent surfaces. This includes studies to minimise the measurement du- ration without a loss in the resolution. Our method to calibrate our measurement system will also be shown. This calibration is needed to reach a resolution below 10 µm.Speaker: Mr Ralph Müller (LMU)
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Inside Holmes experiment: 163Ho metallic target production for the micro-calorimeter absorberThe main goal in the HOLMES experiment is the neutrino mass measurement using an array of 1000 microcalorimeters with standard metallic absorber. A good isotope for such measurement is the 163Ho, those isotopes embedded in the metallic absorber will be 1012. Since 163Ho is not available in nature, a dedicated process must be set up to produce the amount needed for this neutrino mass experiment. The process with the highest born-up cross section is the neutron irradiation of Er2O3 enriched in 162Er:162Er(n,γ)163Er→163Ho+νe, where the decay is an EC with half-life of about 75 min and the σ(n,γ) is about 20 barns for thermal neutron. After the neutron irradiation in the oxide powder there are several radioactive isotopes which are potentially disturbing the background below 5 keV. The chemical separation of holmium from the irradiation enriched Er2O3 powder is therefore mandatory and will be performed by means of ion exchange chromatography. On the end of those processes the oxide powder enriched in 162Er will have the 163Ho isotope number required. The holmium chemical state influences the end point of the EC spectrum, in order to avoid such effect it is necessary to embedded in the absorber only the metallic isotope. Reduction and distillation technique allowed us to obtain a pure metallic holmium, starting from natural oxide holmium. This technique will be applied on the irradiated oxide powder to obtain the metallic 163Ho, ready to be embedded in the micro-calorimeter absorber.er.Speaker: Giulio Pizzigoni (GE)
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MC study of the measurement of Michel Parameters in the radiative leptonic decay of tauMichel Parameters are dimensionless parameters, which describe kinetic nature of lepton's leptonic decay. They have specific values under the assumption of the SM. Hence, measurement of deviation in experiment from the SM values gives hints to new physics. In this poster, I present current status of Monte Carlo study of the measurement of the Michel Parameter in the radiative decay of tau at Belle experiment.Speaker: Mr Nobuhiro Shimizu (The University of Tokyo)
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MONDO: a neutron tracker for particle therapy secondary emission fluxes measurementsParticle therapy (PT) is a novel technique that uses accelerated charged particles for cancer treatment. The PT high irradiation precision and conformity allows the tumor destruction while sparing the surrounding healthy tissues. Monitoring methods using photons and charged particles have already been proposed, but no attempt has yet been made to use the abundant fast neutron component. The large penetrating power of neutrons produces nearly energy threshold free escape, providing a secondary particle sample that is higher in number with respect to photons and charged particles. Therefore, neutrons allow for a backtracking of the emission point that is not affected by multiple scattering. Since neutrons can release a significant dose far away from the tumor region, a precise measurement of their flux, production energy and angle distributions is eagerly needed in order to improve the Treatment Planning Systems (TPS) software, so to predict not only the normal tissue toxicity in the target region, but also the risk of late complications in the whole body. Up to now, neutrons secondary emission has been very poorly investigated for monitoring purpose. This underline the importance for an experimental effort devoted to the precise measurement of the neutron production, induced by the beam interaction with body tissues. The technical challenges posed by a neutron detector aiming for high detection efficiency and good backtracking precision will be addressed within the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project. The MONDO main goal is to develop a tracking detector capable of a full reconstruction and backtracking of secondary neutrons produced by the primary beam interaction with the patient body. The full reconstruction of protons, produced in elastic interactions, will be used to measure the kinematic of the impinging neutron in the (20-300) MeV kinetic energy range. The neutron tracker will measure the neutron production yields, as a function of production angle and energy, using different therapeutic beams at CNAO in Pavia (protons, 12C ions and possibly 4He and 16O ions). A device will reduce significantly the large uncertainties currently related to the neutrons flux estimate produced in typical PT treatments, as well as in other medical therapies involving the neutrons production.Speaker: Davide Pinci (ROMA1)
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Neutron Detection by Large NaI CrystalIn present days new neutron detection methods are under development due to the global shortage of 3He and the toxicity of BF3. We present an indirect method based upon detection of photons emitted in neutron reactions such as neutron capture and inelastic scattering. One of the advantages of this approach is that the detector can also be used simultaneously as a gamma spectrometer. Experimental studies were performed with a 4”x4”x8” NaI crystal and 252Cf and AmBe neutron sources. Scintillation pulses caused by charged heavy particles decay more slowly than those caused by charged lighter particles. Pulses caused by neutron scattering or neutron-induced alpha particles can thus be discriminated from pulses caused by photons. Measurements show that the most important contribution to the detector signal is coming from the neutron capture reaction by iodine in the crystal. The detection efficiency can be improved significantly by covering the detector external sides with polyethylene and polyvinylchloride. These two materials play the double role of moderator and converter. A MonteCarlo investigation devoted to the optimization of the possible converter materials surrounding the NaI detector restricted the solution to chlorine and iron but the simulations show polyvinylchloride performs better than the iron (and it is much lighter). The moderator and converter could also lower the detector background, with a further improvement of the detection limits. The MonteCarlo code pointed out that the effect of the converter is negligible if the thickness of the moderator and converter layer is less than 4 cm and with a layer thicker than 10 cm the efficiency does not improve significantly. The NaI spectrometer surrounded by the proper moderator/converter layer was compared with a standard 3He detector for portal monitor application. We found that efficiencies and minimum detectable activities are roughly of the same order of magnitude thanks to the much higher density of NaI crystal and the neutron capture cross section of iodine. The indirect detection of neutrons by photons has several advantages. First, this method can in principle be suited by any gamma spectrometer (as BGO for instance) with only slight modifications that do not compromise its spectroscopic capabilities: usual gamma spectrometry measurements and neutron detection can be performed simultaneously. Seen from this side the present method results much more convenient: we can perform two functions with the same equipment. Second, fission neutron sources and neutron generators (such as AmBe sources) can be discriminated thanks to their different gamma energy spectra, a discrimination easily done by NaI spectrometer. Third, as will shortly discuss in this paper, the indirect detection approach gives better performances if the neutron source has been shielded using hydrogen-rich or boron-rich material. In general, on-field analysis and data management are much easier to perform with only one detector type instead of having to deal with a gamma spectrometer and neutron detector (like for instance 3He). The list of these advantages makes this experimental solution based upon a portable NaI spectrometer properly shielded, especially interesting for security applications.Speaker: Andrea Lavagno (TO)
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Performance of a 64-channel, 3.2x3.2cm2 SiPM tile for TOF-PET applicationWe present the first results of timing and energy resolution of a newly developed 64-channels tile with FBK SiPMs. The tile has dimensions of 32x32 mm2 and it is composed of an array of 8x8 SiPMs, having a regular pitch along the x and y directions of 4 mm. The fill factor at the tile level is 85%. We designed two versions: one with single-ended and the other with differential readout. The first prototypes are equipped with RGB-HD SiPMs with a cell size of 25 µm. We tested a tile with single ended readout with a scintillator array, manufactured to perfectly match the tile pitch and composed of 8x8 LYSO crystals with dimensions of 4x4x22 mm3. We used a single-channel setup, based on a fast, discrete amplifier, a digital oscilloscope and a PC, and read one SiPM at a time. We irradiated the detector with 511 keV gamma photons, emitted by a Na22 radioactive source. At 20 °C, we measured an energy resolution of 10.7% FWHM, corrected for saturation. The timing measurements were performed against a known reference detector, whose contribution was subtracted. We compared two conditions: when only one SiPM was biased and read, and when all the 64 SiPMs were biased but only one was read. At 20 °C, we measured a timing resolution of 200 ps FWHM in the first case, and 220 ps FWHM in the second case. Measurements on a second tile production equipped with NUV SiPMs, having a cell size of 40 µm, are ongoing and will be presented at the conference.Speaker: Mr Alessandro Ferri (Fondazione Bruno Kessler)
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Properties of single crystal para-terphenyl as medium for high resolution TOF detectorIn the last years organic scintillators have been largely investigated in order to achieve high light yield together with good time response. It has been showed that pure organic compound with high quality crystalline structure can achieve both this goals. Among a large type of organic compound, para-terphenyl (C18H14) have proven to have practical applications as detector medium for particle physics. In this work, the characterization of different sizes high quality mono-crystal p-terphenyl samples is presented. The optical and scintillation properties (emission spectrum, light yield, attenuation length, decay time) are investigated. Coupling a Silicon Photomultiplier-based readout system to the crystal, a small prototype for a high resolution TOF detector was built; the preliminary results, obtained on a 20x30x3 mm3 sample, with dual-side read-out (Hamamatsu S10931-050P SiPMs) and irradiated with 90Sr source, show a time resolution of ~35ps.Speaker: Matteo De Gerone (GE)
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State of the art silicon photomultipliers with LSO: Ce codoped Ca scintillators achieve 84ps coincidence time resolution for PETThe coincidence time resolution (CTR) of 511keV gamma detectors is becoming increasingly important for time-of-flight positron emission tomography (TOF-PET) since the additional time information enables further background suppression in the reconstructed image. In this work we present CTR measurements performed with the latest generation FBK SiPMs coupled to LSO:Ce codoped 0.4%Ca crystals. We tested two differ- ent technologies, i.e RGB-HD (4x4mm2) and NUV (3x3mm2) both cou- pled to the same LSO:Ce codoped Ca crystals. With NUV SiPMs we measured best CTR values of 84±4ps FWHM for 2x2x3mm3 crystals and 140±5ps FWHM for 2x2x20mm3 crystals. We compare the measurements performed on same detectors at two independent test setups: FBK and CERN, each employing different electronics. The agreement in the results from the two setups was found to be within a few percent. We set these results into perspective against previous measurements on Hamamatsu SiPMs for identical crystals, and study various factors such as single pho- ton time resolution (SPTR), photon detection efficiency (PDE) and light extraction efficiency in order to understand the source of improvement in CTR.Speaker: Mr MYTHRA VARUN NEMALLAPUDI (CERN)
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Study of the performance of CdZnTe detectorsCompared with other type of detectors, CdZnTe(CZT) detectors have their own advantages. CZT has high atomic number of the materials (Z¬Cd=48,ZTe=52) with a high band-gap energy(1.5eV).CZT has a higher detection efficiency for γ compared with scintillator detectors. CZT can be operated at room temperature with no need of cooling compared with high-purity germanium detector. This article introduced the performance of the CZT of different types.Speakers: Mr Sen Qian (IHEP,CAS), Mr Xiangcui Lei (IHEP,CAS)
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The Endo-Rectal probe prototype for the TOPEM projectThe TOPEM project was funded by INFN with the aim of study the design of a TOF-PET system dedicated to prostate imaging. During last year a big effort was put into building the prototype of the endo-rectal probe from all point of view: mechanical, thermal, electrical. A dedicated integrated circuit was adopted to have the minimum dimensions: the TOFPET Asic. The system is composed by a LYSO pixellated crystal is seen by a 128 SiPM matrix on both surfaces: this permits Depth Of Interaction (DOI) measurement. The 4 needed ASIC are handled by a FPGA board which transmit the acquired data over an UDP connection. The external container was made using 3-D printing technology: internal channels on the external surface permit the flowing of controlled temperature (˜ 35 ºC) water. Electronic components power is dissipated using an internal air flow kept at lower temperature (˜ 20 ºC). The probe is MR compatible: a dedicated small antenna can be accommodated in the container. This will permit simultaneous imaging in MRI and PET systems.Speaker: Dr Paolo Musico (I.N.F.N. Genova)
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UA9, a device for crystal assisted collimation in large hadron collidersThe use of bent crystals for beam manipulation in particle accelerators is a well-assessed concept rapidly evolving into practical application. Charged particles interacting with a bent crystal can be trapped in channeling states and deflected by the atomic planes of the crystal lattice. One of the possible applications is “smart” collimation system for particle accelerators. The experiments of the UA9 Collaboration at the CERN-SPS have played a key role for a quantitative understanding of channeling and volume reflection mechanisms. The extension of previous experiment to the Large Hadron Collider has received full support from CERN. Investigation of the channeling process close to a circulating beam ideally requires in vacuum detectors resolving the single particle, which should be located inside the vacuum pipe itself. We designed a detection chain, the CpFM (Cherenkov detector for proton Flux Measurement) composed by a fused silica radiator, a long quartz fibers bundle and a photomultiplier readout by the WaveCatcher electronics. All the components except for the electronics have to withstand very high rate of radiations. The layout of the UA9 detectors in the SPS and LHC, both including CpFM detectors, will be presented and the key tests demonstrating crystal assisted collimation concept thoroughly discussed.Speaker: Dr Walter Scandale (ROMA1)
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Watt’s linkage based large band low frequency sensors for scientific applicationsThe UNISA Folded Pendulum is a very effective mechanical system for the implementation of uniaxial (horizontal and/or vertical) and triaxial seismometers and accelerometers for ground, space and underwater applications, including ultra-high vacuum and cryogenics ones. The UNISA Folded Pendulum innovative architecture, based on the classic Watt-linkage mechanical configuration, allows the design and implementation of very large band sensors (10−7 Hz – 100 Hz), characterized by very high quality factors (Q > 2500 in air, Q > 15000 in medium vacuum) and sensitivities that, for the most common applications, do not depend on the mechanics, but only on the readout techniques (< 10-12 m/sqrt(Hz) with classic LVDT readout). These already unique features are coupled with other very relevant characteristics, like full scalability, high compactness (< 10 cm), lightness (< 300 g), high directivity (> 10000), tuneability (typical mechanical resonance frequencies are in the band 100 mHz – 100 Hz), very high immunity to environmental noises. In this paper we present some UNISA Folded Pendulum based uniaxial and triaxial seismometers and accelerometers, discussing relevant results of laboratory tests and of field applications. Keywords: Seismometer, Accelerometer, Folded Pendulum, Monolithic Sensor.Speaker: Prof. Fabrizio Barone (NA)
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PRaVDA – Towards Clinical-Quality Proton CTProton radiotherapy utilises beams of approximately 200 MeV protons to treat cancer. The dose to healthy tissues before and after the tumour can be significantly lower than with conventional x-ray radiotherapy due to the proton Bragg peak. To ensure the dose is delivered to the correct location three pieces of information are essential: the location and size of the tumour; the position of the patient relative the beam; and the stopping powers of the body tissue between the beam entrance and tumour. Currently, stopping powers are inferred via the conversion of Hounsfield numbers, obtained from an x-ray CT scan, leading to a generally accepted uncertainty on the proton range of 3.5%. By measuring the stopping powers directly, via a proton CT (pCT), these uncertainties will be greatly reduced and patient outcomes improved. The PRaVDA consortium is developing an instrument which will acquire a pCT in addition to performing regular QA of the proton beam and in-treatment beam monitoring. We will outline the methodology of obtaining a pCT, the associated challenges, and the ways PRaVDA aims to overcome these. Particular attention will be paid to the tracking system which uses strip sensors developed by the HEP group at the University of Liverpool, the CMOS devices used to measure the residual proton energy (which incorporate deep wells to allow the use of full CMOS circuitry similar to devices for the ALICE ITS upgrade), and the Geant4 simulation model of the complete system.Speaker: Dr Tony Price (University of Birmingham)
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Status of SLAC TestbeamsWe present the current status and plans of the various electron test beams available at SLAC National Accelerator Laboratory. They span an energy range of a few MeV in our ASTA, mainly used RF structure testing and Ultra Fast Electron Diffraction meaurements, NLCTA, a 120 to 200 MeV linac for free electron laser seeding, dielectric laser acceleration and medical irradiation studies, to ESTB, the End Station (A) Test Beam, which uses 5 Hz of the LCLS 2 to 16GeV beam for LC MDI and general detector R&D studies with primary beam and single electrons, to FACET, which has a very compressed and small spot size 20GeV beam for plasma wakefield acceleration, material science, other advanced acceleration concepts studies and beam diagnostics developments. All facilities will briefly be covered. The main emphasis of this talk will be on ESTB which provides an excellent electron test beam for detector R&D and has been used in its first full year of operation by more than 200 users from 11 different experiments. ESTB will receive an EuDet/AIDA class silicon telescope soon, which will further enhance its capabilities.Speaker: Dr Carsten Hast (SLAC)
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Development Electron Tracking Compton Camera (ETCC) for multipurpose medical imagingPET and SPECT achieved great successes in medical imaging. These detectors, however, have energy limitations, which is a problem in designing new-molecular imaging reagents. We have developed an Electron-Tracking Compton Camera (ETCC) to give the wide energy range (200-1500keV), wide field of view (4str) and abilities of background rejection and clear imaging using the tracking of recoil electrons. Thus ETCC has a potential of the development of new reagents. Until now we carried out several imaging reagent studies of double clinical tracer imaging with FDG and I-131-MIBG, and imaging of Zn-65, Mn-54 and Fe-59 in mice. Also, ETCC images continuum gamma-rays by removing backgrounds using dE/dx of the track, which enables to monitor the Bragg peak location by detecting prompt gammas. We successfully obtained the on-time images of 511keV and continuum gammas rays from the water irradiated by 140MeV proton (S.Kurosawa, Cur.Apl.Phys, 2012). In 2013 we have improved all readout system of ETCC, by which its tracking efficiency and data transfer rate ere improved with 10 times, and 50 times. Now ETCC obtain clear images with the use of 50MBq FGD, and starts the test of tomographic image using two ETCCs. We will present its imaging performance including the proton beam test with similar intensity in proton therapy.Speaker: Prof. Toru Tanimori (Graduate School of Science Kyoto University)
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Coffee break
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Applied Superconductivity in HEPConveners: Flavio Gatti (GE), Giovanni Signorelli (PI)
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Advances of Applied Superconductivity in High Energy PhysicsApplied superconductivity has been a key and inevitable technology to realize energy-frontier particle accelerators and detectors in high energy physics. We will review the technical advances and future prospects, focusing on superconducting accelerator magnets and RF devices and on large-scale detector magnets. Recent progress in superconducting technology for detecting particles will be briefly introduced.Speaker: Prof. Akira YAMAMOTO (KEK and CERN)
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R&D on High Field Magnets for Accelerators at FermilabThe High Field Magnet Program at Fermilab is developing advanced high-field superconducting magnets, materials and technologies for present and future particle accelerators. Since the late 90s the program has focused 10-15 T magnets based on Nb3Sn superconductor. The Program has contributed to several advances in Nb3Sn strand, cable and accelerator magnet technologies. The most important breakthroughs made at Fermilab include the development and demonstration of high-performance Nb3Sn strand and cables stable to flux jumps, reliable and reproducible production-ready short and long coil fabrication technologies, accelerator quality mechanical structures, the first world series of Nb3Sn dipole and quadrupole models with reproducible magnet parameters, innovative field quality correction techniques, etc. These advances in technology make it possible to consider 10-12 T Nb3Sn magnets for the first time in present or future accelerators, and particularly for the planned LHC luminosity upgrades. The Program is presently exploring limits of the Nb3Sn magnet technology by developing a 15 T Nb3Sn dipole demonstrator and working on magnet cost reduction. In the longer term, the program will thrust the development of accelerator magnets beyond Nb3Sn with fields of 20-25 T based on LTS (Nb3Sn) and HTS (Bi-2212 or YBCO). This talk will summarize the main results of the Nb3Sn accelerator magnet and superconductor R&D at Fermilab and discuss the Program next steps and possible applications of its results for the LHC, Muon Collider and FCC.Speakers: Dr Alexander V. Zlobin (Fermi National Accelerator Laboratory), Dr Emanuela Barzi (Fermi National Accelerator Laboratory)
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Superconducting Nanowires Detecting Single Photons for Integrated Quantum PhotonicsQuantum information processing with photons relies on single-photon sources, passive circuit elements and single-photon detectors. In order to take advantage of quantum physics in advanced quantum technologies such as quantum simulation and quantum computing, tens of photons must be generated, manipulated and detected. However, when the number of photons exceeds a few, bulk optics becomes complex and difficult to scale. Integrated quantum photonics offers a solution to these formidable challenges. Quantum photonic integrated circuits (QPICs) may enable the scalable generation, manipulation and detection of single photons on a chip, thereby opening the way to quantum information processing. Superconducting nanowire single-photon detectors (SNSPDs), on the other hand, are a promising enabling technology for single-photon detection due to their fast response, low dark count rates, low jitter and scalability. The integration of SNSPDs with waveguides is therefore of primary importance for the realisation of a scalable and fully-integrated quantum photonic technology. In this talk, we will first describe the deposition of NbN thin films on semiconducting substrates, the nanofabrication of detector structures and the measurement techniques needed to characterise detectors. We then discuss the design of waveguide single-photon detectors and their electro-optical characteristics.Speaker: Dr Roberto Leoni (IFN-CNR, Istituto di Fotonica e Nanotecnologie, Via Cineto Romano 42, 00156 Roma, Italy)
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Superconducting Kinetic Inductance Detectors for kilopixel intruments at RadiotelescopesKinetic Inductance Detectors (KID) is a novel detector technology based on superconducting resonators. Since their first demonstration in 2003, they have rapidly developed and are today a strong candidate for present and future experiments in the millimetric band of the electromagnetic spectrum. This has been possible thanks to the unique features of such devices. In particular, they couple a very high sensitivity to their intrinsic suitability for frequency domain multiplexed readout, a characteristic that is of paramount importance for all instruments needing large arrays of cryogenically cooled detectors. This is the case, for example, of many satellite borne experiment, as well as of ground-based telescopes with high resolution and a large field of view. Among the instruments based on KID, NIKA (New IRAM KID Arrays) has been the first to conduct multiplexed on-sky observations. It has been permanently installed at the IRAM 30m telescope in Sierra Nevada (Spain) in 2012, and has since then carried several successful observation runs open to external astronomers. In June 2015, this camera will be replaced by the new, more powerful NIKA2 camera. In its final configuration, NIKA2 will have a total of approximately 5000 detectors. It will make simultaneous large field-of-view (instantaneous FoV = 0.1 deg) measurements at 2mm (150GHz) and 1.25mm (240GHz), with the latter channel being furthermore polarization sensitive.Speaker: Dr Martino Calvo (Institut Néel, CNRS Grenoble)
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Applied Superconductivity in HEP - Poster Session
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A 16 channel frequency-domain-modulation readout system with custom superconducting LC filters for the SWIPE instrument of the balloon-borne LSPE experimentWe present the design, implementation and first tests of the superconducting LC filters and the frequency domain readout of spiderweb TES bolometers for the SWIPE experiment on the balloon-borne LSPE mission. LSPE is optimized to measure the linear polarization of the Cosmic Microwave Background at large angular scales to find the imprint of inflation on the B-mode CMB polarization. The Short Wavelength Instrument for the Polarization Explorer (SWIPE) is composed of 3 arrays of multi-mode bolometers cooled at 0.3K , with optical components and filters cryogenically cooled below 4K to reduce the background on the detectors. Polarimetry is achieved by means of large rotating half-wave plates and wire-grid polarizers in front of the arrays. In SWIPE angular resolution is traded off for sensitivity. Microwave radiation will be detected at the three frequencies of 140, 220 and 240 GHz to disentangle the expected cosmological signal from inflation from the galactic and extragalactic background, for a 13 days survey covering 25% of the sky. LC filters are designed, produced and tested at the INFN secions of Pisa and Genova where thin film deposition and cryogenic test facilities are present, and where also the TES spiderweb bolometers are being produced.Speaker: Giovanni Signorelli (PI)
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Cryogenic light detectors for the search of neutrinoless double beta decayCALDER (Cryogenic wide-Area Light Detectors with Excellent Resolution) is a project for development of large area phonon mediated KID (Kinetic Inductance Detectors), for the detection of Cherenkov radiation emitted from βs in 0nDBD decay in TeO2. The KIDs are a superconducting detectors mode of high quality factor superconducting resonators, which are coupled to a transmission line for readout signal. We designed and fabricated KID detectors using aluminum. The Al thin films (40 nm) were evaporated on Si(100) high resistivity silicon wafers using an electron beam evaporator in a high vacuum chamber. We report the steps of the fabrication process. All devices are made in direct-write using Electron Beam Lithography (EBL), positive tone resist poly-methyl methacrylate (PMMA) and lift off process. In order to improve the sensibility of the detectors we have started recently to use sub-stoichiometric TiN deposited by means of DC magnetron sputtering. In this case we will optimize a different fabrication process based on dry etch.Speaker: Ivan Colantoni (Università Roma2 and INFN)
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Fabrication and test large area spider-web bolometer for CMB polarization experimentThe polarization structure of the Cosmic Microwave Background (CMB) is one of the major challenges of modern observational cosmology. Microwave telescopes need sensitive cryogenic bolometers with an overall equivalent noise temperature in the nK range. In this poster, we present the development status of multimode spider-web bolometers for the balloon born mission “Large Scale Polarization Explorer” (LSPE). Multimode detection isn’t no more used in microwave detection since many decades. This approach gives larger signal to noise ratio and it is not a limitation for the science goal of detecting B mode. Multimode bolometers have large area, about 1 cm2, that imply additional fabrication challenges. The spider-web is a suspended Si3N4 1 um thick and 8 mm diameter with mesh size of 250 μm. They are designed in order to couple with approximately the first 20 modes of the cavity at about 140 GHz. The thermal sensitive element is a superconducting Mo-Au bilayer Transition Edge Sensor (TES) at the center of the bolometer. We present the fabrication process with micro machining techniques from silicon wafer covered with SiO2 - Si3N4 CVD thick films, 0.3 μm and 1 μm respectively and preliminary testes.Speaker: Giulio Pizzigoni (GE)
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Feasibility Study of Hybrid Magnetic Cloak for Accelerator MagnetsIt is well known that superconducting (SC) materials repel magnetic field, whereas paramagnetic ones concentrate flux lines in their interior. By using concentric tubes of the two materials, the magnetic field inside a cylinder is canceled without modifying the external applied field. Analytical solutions exist, which provide a relation between the thickness of the paramagnetic material and the relative permeability necessary for a complete cloaking. In this paper we perform a feasibility study on whether this concept works to shield large magnetic fields, by using bulk MgB2 superconductor prepared by the Reactive Liquid Infiltration (RLI) in-situ process. With conventional ovens, it is possible to produce large superconducting bulk pieces using this patented technology. A number of paramagnetic materials have been searched for, and their magnetic permeability measured. Tube junctions have been studied, as well as effects of tube ends, geometry and flux jumps. A successful hybrid cloak would find immediate application at FNAL in the Muon g-2 experiment, which presently relies on a SC inflector magnet to cancel the 1.5 Tesla storage ring field seen by the muon beam at injection.Speaker: Dr Emanuela Barzi (Fermi National Accelerator Laboratory)
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High-Tc superconductors as accelerators wall coatings in FCC-hh: Impedance and compatibility with collective effects issues.One of the ambitious goals of current studies on accelerators is the possibility to work at the highest energy frontier even after the LHC era. To this aim, CERN is preparing a conceptual design report for Future Circular Colliders (FCC) with emphasis on proton-proton (hh) high-energy frontier machines. For FCC-hh one of the foreseen effort is the reduction of the machine impedance to allow to operate at high beam currents. One of the potential solution is the use of high-Tc superconductors as accelerator wall coating. This will require theoretical and experimental validation to see whether the impedance can be brought to the desired values in all frequency range. Low impedance is not the only characteristic required by a wall coating. Positively charged beams may suffer from unconventional interaction with vacuum components. Beam instabilities are predicted, and, in some cases, observed, as caused by the mere presence of low energy electrons in the beam pipe. Such electrons are known to be produced by photo and/or electron interactions with the accelerator walls. The detailed characterization and the precise control of surface properties like surface chemistry, Secondary Electron Yield (SEY), Photoemission, Photoelectron Yield (PY), photon Reflectivity (R) for high-Tc superconductor surfaces is then required to qualify such materials as a potential solution to the foreseen impedance issues. Here, we present a tentative master plan for future activities at INFN.Speaker: Roberto Cimino (LNF)
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Kinetic Inductance Detectors for Far-Infrared SpectroscopyThe star formation mechanisms at work in the early universe remain one of the major unsolved problems of modern astrophysics. Many of the luminous galaxies present during the period of peak star formation (at redshift of about 2.5) were heavily enshrouded in dust, which makes observing their properties difficult at optical wavelengths. However, a rich variety of spectral lines exist at far-infrared wavelengths that serve as tracers of star formation. Here, we describe a detector system suitable for a balloon-borne spectroscopic intensity mapping experiment at far-infrared wavelengths. The system uses lumped-element kinetic inductance detectors (LEKIDs), which have the potential to achieve high sensitivity and low noise levels. LEKIDs consist of separate capacitive and inductive elements, and use the inductive element as the radiation absorber. We describe the design considerations, fabrication process, and readout scheme for a prototype LEKID array of 1600 pixels.Speaker: Ms Alyssa Barlis (University of Pennsylvania)
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Microwave multiplex read out for superconducting sensorsThe calorimetric measurement of the energy released in a nuclear beta decay is a powerful tool to determine the effective electron-neutrino mass. In the last years, the progress on low temperature detector technologies has allowed to design large scale experiments aiming at pushing down the sensitivity on the neutrino mass below 1 eV. Even with outstanding performances in both energy (~ eV on keV) and time resolution (~ 1 microsecond ) on the single channel, a large number of detectors working in parallel is required to reach a sub-eV sensitivity. Microwave frequency domain read out is the best available technique to read out large array of low temperature detectors, such as Transition Edge Sensors (TESs) or Microwave Kinetic Inductance Detectors (MKIDs). This microwave multiplexing system will be used to read out the HOLMES detectors, an array of 1000 microcalorimeters based on TES sensors in which the 163Ho will be implanted. HOLMES is a new experiment for measuring the electron neutrino mass by means of the electron capture (EC) decay of 163Ho. We present here the microwave frequency multiplex which will be used in the HOLMES experiment and the microwave frequency multiplex used to read out the MKID detectors developed in Milan as well.Speaker: Mrs Elena Ferri (MIB)
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Status of the HOLMES detector developmentHOLMES is a new experiment to directly measure the neutrino mass with a sensitivity as low as 0.4 eV. HOLMES will perform a calorimetric measurement of the energy released in the electron capture decay of $^{163}$Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. HOLMES will deploy a large array of low temperature microcalorimeters with implanted $^{163}$Ho nuclei. The detectors used for the HOLMES experiment will be Mo/Cu superconducting Transition Edge Sensors (TES) on SiN$_x$ membrane with bismuth absorbers. The detectors require a special two step fabrication process to allow the $^{163}$Ho nuclei embedding. The signals from the microcalorimeter array will be read-out with a microwave multiplexing system combined with an FPGA based digital acquisition system which implements a Software Designed Radio. HOLMES baseline detector is an array of 1000 microcalorimeters each with an implanted $^{163}$Ho activity of about 300 Bq, an energy resolution FWHM of about 1 eV at the spectrum end-point ($Q\approx 2.5$\,keV), and a time resolution of about 1\,$\mu$s. Matching these performances requires a careful optimization of all components, from the microcalorimeters to the signal processing algorithms. We outline here the project technical challenges and the present status of the development. HOLMES is funded by the European Research Council (GA n. 340321).Speaker: Angelo Enrico Lodovico Nucciotti (MIB)
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Superconducting TES array for large area cryogenic anti-coincidence detector for the ATHENA space missionATHENA, the large X-Ray mission proposed to the European Space Agency, will operate the largest array of superconducting TES micro-calorimeters at 50 mK with 2 eV FWHM resolution in L2. Cosmics (protons and light nuclei) are expected to produce a high background resulting in a loss of detection of efficiency of faint diffuse or far X-ray source like Worm Hot Intergalactic Medium or weak spectral signature from AGN and GRBs. In order to reach the high sensitivities required for the scientific goal of the missions, it is mandatory to discriminate these fake events. A GeV protons and light nuclei detector, 1 mm beneath the microcalorimeter array, is proposed as anti coincidence detector. It is made of 6 cm2 silicon micro-machined chip that detects cosmics by means of fast a-thermal and thermal phonons. The signal is produced by hundreds of superconducting and uniformly distributed small TES, that are fabricated on the silicon chip surface. The surface coverage index can be increased by means of superconducting phonon collectors directly connected with the TESs. Here we present the performance of the samples with and without phonon collector, with the purpose of fine comprehension of the detector physics, together with the design of the next detector generation, which will allow us to reach the technology readiness level 4 (TRL4) for this mission phase A.Speaker: Flavio Gatti (GE)
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Phonon-Light Detectors for the CRESST dark matter searchCRESST-II is a cryogenic direct dark matter search aiming for the detection of WIMPs via elastic scattering off nuclei in CaWO4 target crystals. CRESST detectors are optimized for low thresholds and a precise energy reconstruction in order to measure tiny nuclear recoils (<1keV), which are expected for light WIMPs (O(1GeV/c2)). Phonons induced by particle interactions in the target crystal are detected by a transi- tion edge sensor (TES) on the scintillating CaWO4 crystal. The TES consists of a thin tungsten film which is stabilized very precisely in a point in its superconducting transi- tion at mK temperatures over the whole measurement period. For an active background discrimination we use an additional light detector which detects the scintillation light of the CaWO4 crystal. It consists of a light absorber also equipped with a tungsten TES. In the ongoing run of CRESST-II one of the phonon detectors provides a threshold of 0.60keV and a resolution of 0.090kev (at 2.60keV). The light detectors are sensitive enough to detect energy depositions down to 5keV. For the next phase of the CRESST experiment we will use new detector modules optimized to measure even lower recoil energies (0.1keV) to further enhance the sensitivity for low WIMP masses.Speaker: Anja Tanzke (Max-Planck-Institute for Physics)
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Gas DetectorsConveners: Dr Archana SHARMA (CERN), Gloria Spandre (PI)
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Status Report of the Upgrade of the CMS muon system with triple-GEM detectorsFor the LHC High Luminosity phase (HL-LHC) the CMS GEM Collaboration is planning to install new large size (990 x 440-220 mm2) triple-GEM detectors, equipped with a new readout system, in the forward region of the muon system (1.5<|η|<2.2) of the CMS detector. Combining triggering and tracking functionalities the new triple-Gas Electron Multiplier (GEM) chambers will improve the performance of the CMS muon trigger, and will also improve the muon identification and track reconstruction. With the addition of triple-GEM detectors the forward region of the CMS muon spectrometer will recover its originally planned redundancy. Starting from 2009 the CMS GEM Collaboration built several small and full size prototypes with different geometries, keeping improving the assembly techniques. All these prototypes have been tested in laboratories as well as with beam tests at the CERN SPS and at Fermilab. The results show that the triple-GEM detectors are a mature technology satisfying all the requirements to be used in the forward region of the CMS muon system at HL-LHC. In this contribution we will report on the status of the CMS upgrade project with GEMs and its impact on the CMS performance as also the hardware architectures and expected performance of the CMS GEM readout system. We will also present the latest results on the new generation of chamber using 2014 test beam data. During this test beam, the new CMS GEM readout electronics based on the micro-TCA standard has also been used.Speaker: Dr Gilles De Lentdecker (Université Libre de Bruxelles)
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Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS ExperimentLarge area Micromegas (MM) detectors will be employed for the Muon Spectrometer upgrade of the ATLAS experiment at the LHC. A total surface of about 150 m^2 of the forward regions of the Muon Spectrometer will be equipped with 8 layers of MM modules. Each module covers a surface area of approximately 2 to 3 m^2 for a total active area of 1200 m^2. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the planned 2018/19 shutdown. The NSW project requires fully efficient MM chambers with spatial resolution down to 100 um, a rate capability up to about 15 kHz/cm^2 and operation in a moderate magnetic field up to B=0.3 T. The required tracking capability is provided by the intrinsic spatial resolution combined with a challenging mechanical precision. The design, recent progress in the construction and results from the substantial R&D phase (with a focus on novel technical solutions) will be presented. In the R&D phase, small and medium size single layer prototypes have been built, along with, more recently, the first two MM quadruplets in a configuration very close to the final one chosen for the NSW. Several tests have been performed on these prototypes at a high-energy test-beam at CERN. Recent tests applying various configuration and operating conditions, for example magnetic field dependences, will also be presented.Speaker: Michele Bianco (INFN)
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A continuous read-out TPC for the ALICE upgradeThe largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb-Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at a rate of up to 1 TByte/s. To keep distortions due to space charge from back-drifting ions at a tolerable level, an ion feedback of below 1 % is required. The new read-out chambers will consist of stacks of 4 GEM foils combining different hole pitch. In addition to a low ion backflow other key requirements such as energy resolution and operational stability have to be met. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.7 %, a local energy resolution of 12 % (sigma) and a discharge probability for irradiation with alpha particles of the order of 10^(-10). We will give an overview on the upgrade plans and report on the R&D program and beam tests conducted with large scale Read-Out Chamber prototypes.Speaker: Dr Christian Lippmann (GSI Helmholtzzentrum für Schwerionenforschung)
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TPC-like readout for thermal neutron detection using a GEM-detectorPosition resolving detection of thermal neutrons combined with timing information and high flux capability are key features of detectors in spallation sources like the ESS. In order to reach the extremely low spatial resolution of less than 200 µm for neutron tomography or radiography novel readout scheme based on the time-projection-chamber (TPC) concept is used in a gaseous electron multiplier (GEM) detector. Thermal neutrons are captured in a single 2 µm thick Boron-10 converter cathode and secondary Helium and Lithium ions are produced with a combined energy of 2.8 MeV. These ions have sufficient energy to form tracks of several mm length. With a time resolving 2-dimensional readout of 400 µm pitch in both directions, based on APV25 chips, the ions are tracked and their respective origin in the cathode converter foil is reconstructed. Using n Ar-CO2 93:7% gas mixture, a resolution of 100 µm has been observed with a triple GEM-detector setup at the Garching Neutron source (FRMII) for neutrons of 4.7 A.Speaker: Mr Bernhard Flierl (LMU Munich)
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Cylindrical Micromegas, an innovative solution for central trackers.A Micro-mesh Gaseous Detector, or Micromegas, is a parallel plate detector used in tracking apparatus for its low material budget, good spatial and time resolutions, and high rate capabilities. Recent development in the fabrication of the detector, the bulk technology, has made the detector monolithic by embedding the micro-mesh on the readout electrode. This allowed to curve the detector with a minimal mechanical support and opened the possibility to have very light, self supported, cylindrical Micromegas. With a spatial resolution around 100um, a low material budget with 0.33% of X0, and magnetic field compatible technology; cylindrical Micromegas offer a competitive alternative for central trackers with high-rate capabilities of the order 150kHz/strip. This talk will report on the CLAS12 central tracking project and its innovative solution consisting in a 6 layers Micromegas barrel. The first chambers have been produced and their full characterization will be reported. The CLAS12 design has been adapted and successfully operated in the CERN anti-hydrogen experiment ASACUSA. The performances of the 10cm-radius 30cm-length two layers cylindrical Micromegas will be presented. Finally we will discuss future directions for this technology, focusing an an application for the central tracking at the Electron Ion Collider (EIC).Speaker: Dr Maxence Vandenbroucke (CEA Saclay)
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Resistive MPGDs based on the WELL amplification conceptIn this work we present two innovative architectures of resistive MPGDs based on the WELL-amplification concept: - the micro-Resistive WELL ($\mu$-RWELL) is a compact spark-protected single amplification-stage Micro-Pattern Gas Detector (MPGD). The amplification stage, realized with a structure very similar to a GEM foil (called WELL), is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new architecture, showing an excellent space resolution, $\sim$50 $\mu$m, is a very compact device, robust against discharges and exhibiting a large gain (>$10^{4}$), simple to construct and easy for engineering and then suitable for large area tracking devices as well as digital calorimeters. - the Fast Timing Micro-pattern (FTM): a new device with an architecture based on a stack of several coupled full-resistive layers where drift and multiplication stages (WELL type) alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings, providing a signal with a gain of $10^{4}\,-\,10^{5}$. The main advantage of this new device is the improvement of the timing provided by the competition of the ionization processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as for applications like medical imaging.Speaker: Marco Poli Lener (LNF)
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Charge Transfer Properties Through Graphene for Applications in Gaseous DetectorsGraphene is a single layer of carbon atoms arranged in a honeycomb lattice with remarkable mechanical, electrical and optical properties which make this material interesting in a number of applications. It can be regarded as the thinnest and narrowest conductive mesh, with drastically different transmission behaviours when bombarded with electrons and ions. Graphene layers of dimensions of about 2x2cm^2, grown on a copper substrate, are transferred onto a metal surfaces with holes of diameters from 30um to 70um and a pitch of the order of 150um, so that the graphene layer is freely suspended. The graphene and the support are installed into a gaseous detector equipped with a triple Gaseous Electron Multiplier (GEM), and the transparency properties to electrons and ions are studied in gas as a function of the electric fields applied. The techniques to transfer the graphene from the substrate to the support, and the procedures to measure the charge transmission properties will be described. First results will be presented, spotting the difficulties arising from the defects in the graphene layers and presenting the solutions to study the intrinsic transmission properties of this material. We will also discuss the applications where these techniques can be used to improve the state of the art of gaseous detectors.Speaker: Filippo Resnati (CERN)
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Gas Detectors - Poster Session
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A Dedicated Calibration Tool for the MEG and MEGII Positron SpectrometerThe MEG experiment has set the latest upper limit of $5.7\times10^{-13}$ (90\thinspace\% C.L.) on the branching ratio of the $\mu^{+}\rightarrow e^{+}\gamma$ decay, making use of the most intense continuous surface muon beam in the world at the Paul Scherrer Institut, Villigen. High resolutions in terms of energy, timing and relative opening angle are needed in the detection of the $e^{+}$ and gamma, requiring careful calibration and monitoring of the experimental apparatus. In this poster, a new calibration method involving Mott scattering of a monochromatic positron beam at energies close to the MEG signal energy will be presented. This method provides a powerful tool to study the positron spectrometer's properties in an independent way, allowing for example the extraction of the positron variable resolutions or the alignment of the drift chamber system.Speaker: Ms Giada Rutar (Paul Scherrer Institut Villigen and ETHZ)
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A compact Time Projection Chamber for the Crystal BallThe Crystal Ball Collaboration uses the energy tagged photonbeam facility in Mainz, Germany, to study photo-induced reactions on nucleons and nuclei. The Crystal Ball/TAPS $4\pi$ calorimeter setup is optimized for the detection of neutral final states. Charged particles are identified and measured by the inner detector system including a two layer MWPC. The increased rate of charged particles in current and future experiments exceeds the rate capability of these MWPCs. We are developing a small Time Projection Chamber with triple GEM readout meeting the stringent space requirements of the Crystal Ball experiment. This new tracking detector will feature higher rate capabilities and allows better track reconstruction. We are investigating the use of Carbon Fiber Reinforced Plastics (CFRP) to build light but strong chamber walls. First tests with carbon fiber prepregs show promising results. In addition we are using the PLUTO event generator to study the detector acceptance under our experiment conditions. Similar simulations are done to optimize the number and the shape of the readout pads. This poster will give an overview of the current status of the project and present the latest results.Speaker: Mr Oliver Steffen (Institut für Kernphysik, Universität Mainz)
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A new construction technique of high granularity and high transparency Drift Chambers for modern High Energy Physics experimentsModern experiments for the search of extremely rare processes require high resolutions (order of 50-200 keV/c) tracking systems for particle momenta in the range of 50-300 MeV/c, which is totally dominated by multiple scattering contributions. We present a newly developed construction technique for ultra-low mass, high granularity Drift Chambers fulfilling this goal. It consists of: • a semiautomatic wiring machine with a high degree of control over wire mechanical tensioning (better than 0.5g) and over wire positioning (of the order of 20µm) for simultaneous wiring of multi-wire layers; • a contact-less IR laser soldering tool designed for a feed-through-less wire anchoring system; • an automatic handling system for storing and transporting the multi-wire layers to be placed over the drift chamber end-plates. These techniques have been successfully implemented at INFN-Lecce and University of Salento and are currently being used for the construction of Drift Chamber of the MEG (µ→e+γ) upgrade experimentSpeaker: Gianluigi Chiarello (LE)
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A new cylindrical drift chamber for the MEG-II experimentA new cylindrical drift chamber for the MEG-II experiment is currently under construction. The chamber is used to track low momentum positrons from the $\mu^+$ decays to search for $\mu^+ \rightarrow e^+ \gamma$ events. The chamber is made of very small drift cells, placed in stereo configuration for longitudinal hit localisation and operated in a helium-isobutane gas mixtures. The use of thin aluminium wires and the light gas mixture set the total radiation length of the chamber to only $1.6 \times 10^{-3} X_0$ allowing for a momentum resolution of $\approx 120$ keV/c .Speaker: Marco Grassi (PI)
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A novel method to estimate the impact parameter on a drift chamber cell by using the information of single ionization clusters.Gaseous wire drift chambers are a common device for tracking charged particles to extract information on their momentum or type. A particle crossing a drift chamber cell produces several ionization clusters, but only the signal coming from the cluster which is closest to the anode wire is usually exploited to extract the impact parameter. This introduces a bias, especially in tracking chambers where light gas mixtures are needed, where the number of ionization clusters is limited to $\sim 10$/cm. Measuring the time of each ionization cluster has been proposed in the past to improve the impact parameter reconstrucion, reducing the bias and the single hit resolution, and ad-hoc formulae have been developed to combine information on the single clusters. We show that the problem of finding an estimator of the impact parameter can be solved with an algorithm called Maximum Possible Spacing (MPS), which provides a statistically optimal estimator in this case and, unlike the algorithms proposed to date, does not rely on the knowledge of specific parameters of the detector. We will describe the MPS approach in comparison with other proposed algoritms, and show its application on simulations. The application of this method to a real situation is also discussed.Speaker: Marco Venturini (PI)
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A proposal to upgrade the ATLAS RPC system upgrade for the High Luminosity LHCThe architecture of the present trigger system in the ATLAS muon barrel was designed according to a reference luminosity of 10^34 cm^-2 s^-1 with a safety factor of 5, with respect to the simulated background rates, now confirmed by LHC Run 1 data. HL-LHC will provide a luminosity 5 times higher and an order of magnitude higher background. As a result, the performance demand increases, while the detector being susceptible to aging effects. Moreover, the present muon trigger acceptance in the barrel is just above 70%, due to the presence of the barrel toroid structures. This scenario induced the ATLAS muon Collaboration to propose an appropriate upgrade plan, involving both detector and trigger-readout electronics, to guarantee the performance required by the physics program for the 20 years scheduled. This consists in installing a layer of new generation RPCs in the inner barrel, to increase the redundancy, the selectivity, and provide almost full acceptance. The first 10% of the system, corresponding to the edges of the inner barrel even sectors (BIS), has been already approved by ATLAS and will be installed in 2018, to reinforce the trigger in the region between barrel and endcap. To match the performance requirements, the new RPCs will have a different structure, materials and a high performance front-end electronics, in SiGe technology. We will illustrate the performance of the new detectors and trigger system, as well as the impact on the ATLAS physics performance.Speaker: Riccardo Vari (ROMA1)
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Building and Commissioning of a Setup to Study Ageing Phenomena in Gaseous DetectorsIn high-rate heavy-ion experiments, gaseous detectors encounter big challenges in terms of degradation of their performance due to a phenomenon called ageing. A setup for high precision ageing studies has been constructed and commissioned at the GSI detector laboratory. Several improvements of the setup design and the gas system have been implemented to achieve the required accuracy of the ageing measurements. The ageing effects of two materials have been carried out: RTV-3145 and Gerband 705. The details of construction of this automatic ageing setup and the test results will be presented.Speakers: Dr Saikat Biswas (National Institute of Science Education and Research), Mr alhussain Abuhoza (GSI)
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Characterization and Calibration of Large Area Resistive Strip Micromegas DetectorsResisitve strip Micromegas detectors behave discharge tolerant. They have been tested extensively as smaller detectors of about 10 x 10 cm^2 in size and they work reliably at high rates of 100 kHz/cm^2 and above. Tracking resolutions well below 100 um have been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3m^2 in size. To investigate possible differences between small and large detectors, a 1m^2 detector with 2048 resistive strips at a pitch of 450 um was studied in the LMU Cosmic Ray Facility (CRF) using two 4 x 2.2 m^2 large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. Segmentation of the resistive strip anode plane in 57.6mm x 95mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by 11 95mm broad trigger scintillators placed along the readout strips. This allows for mapping of homogenity in pulse height and efficiency, determination of signal propagation along the 1m long anode strips and, very important, calibration of the position of the anode strips. Additionally, we report on studies of the charge-up behavior of the resistive strip anodes and related simulations of mesh-transparency, a non-trivial aspect, as thicker meshes than usual have to be used for the large area application.Speaker: Mr Philipp Lösel (Ludwig-Maximilians-Universität München)
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Characterization of the ATLAS Micromegas quadruplet prototypeA Micromegas detector with four active layers, serving as prototypes for the upgrade of the ATLAS spectrometer, was designed and constructed in 2014 at CERN and represents the first example of a Micromegas quadruplet ever built. The detector has been realized using the resistive-strip technology and decoupling the amplification mesh from the readout structure. The four readout planes host overall 4096 strips with a pitch of 400μm, two layers have strips running parallel (η in the ATLAS reference system, for measuring the muon bending coordinate ) and two layers have stereo strips inclined by ±1.5◦ with respect to the η coordinate in order to provide measurement of the second coordinate. A complete detector characterization carried out with cosmic muons as well as with particles beam is presented. A novel method based on X-Ray irradiation, used for fast detector characterization and relative strips alignment checking is presented with the obtained results. Finally preliminary ageing results from test carried out at the new CERN Gamma Irradiation Facility (GIF++) are shown.Speaker: Dr Ourania Sidiropoulou (University of Wuerzburg)
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Characterizations of GEM detector prototypeGas Electron Multiplier (GEM) is one of the most important micro-pattern gaseous detectors used in the recent and being considered for future High-Energy Physics (HEP) experiments [1, 2]. For example ALICE at the Large Hadron Collider Facility is upgrading its multi-wire proportional chamber based Time Projection Chamber (TPC) with GEM units. In line with the worldwide efforts, we have also taken an initiative in our experimental high-energy physics detector laboratory build and test of GEM detector prototypes. The GEM foils and other components are obtained from CERN. The detector has been tested with Co60, Cs137 and Sr90 radioactive sources with Ar/CO2 gas in 70/30 ratios. The temperature and atmospheric pressure has been measured and recorded continuously using a data logger developed in-house. Effect of Temperature and Pressure on count rate has also been measured. Variation of the count rate has also been measured with varying flow rate. The details test results will be presented. The results of long term stability test will also be presented.Speakers: Ms SHARMILI RUDRA (University of Calcutta), Dr Saikat Biswas (National Institute of Science Education and Research)
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Cluster ions in gas-based detectorsAvalanches in gas-based detectors using $\mathrm{Ar}\mbox{-}\mathrm{CO}_2$ or $\mathrm{Ne}\mbox{-}\mathrm{CO}_2$ as drift medium produce in a first instance $\mathrm{Ar}^+$, $\mathrm{Ne}^+$ and $\mathrm{CO}_2^+$ ions. Although there is a wealth of information in the literature about ion transport and ion chemistry, some gas-detector simulations simplify the treatment of ions to excess, e.g. by taking only the noble gas ions into account, neglecting the role of the quencher. The noble gas ions transfer their charge to $\mathrm{CO}_2$ in a few ns. Over the next few ns the $\mathrm{CO}_2^+$ ions pick up $\mathrm{CO}_2$ molecules and thus cluster ions, in particular $\mathrm{CO}_2^+\cdot(\mathrm{CO}_2)_n$ are formed. Since the cluster ions are $\sim 20~\%$ slower than the initial ions, the ion-induced signals are substantially altered. The effect is shown to be present in constant-field detectors (LIP-Coimbra) and TPC readout chambers (ALICE and NA49), and is expected to affect devices such as Micromegas and drift tubes.Speakers: Mr Mesut Arslandok (Goethe University), Mr Yalçın Kalkan (Uludağ University, Bursa)
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Construction and Performance Studies of a Micromegas Detector with a Pad Readout GeometryWe report on the design and the performance of a prototype detector based on Micromegas technology with a pad readout geometry. The prototype detector consists of 500 pads covering an active area 10x10 cm. Each pad has a size of 6x4 mm and is connected to an individual readout channel. The design of this prototype and its associated readout infrastructure was developed such, that it can be easily adapted for large size detector concepts. In addition, two alternative implementations of a spark-resistent insulating layer on top of the readout pads of the prototype detector have been implemented and tested to optimize the charge-up behavior of the detector under high rates. The corresponding concepts have never been implemented for Micromegas detectors before. The aim of our prototype detector is to provide a solution for the coordinate matching ambiguity of two orthogonal one-dimensional precision tracking chambers under high raters.Speaker: Mr Andreas Duedder (Uni. Mainz)
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Construction and commissioning of the SuperNEMO detector trackerThe SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory with a sensitivity of |mββ|<0.05÷0.1 eV; the detector design allows complete topological reconstruction of the event enabling excellent background rejection and, eventually, the ability to determine the nature of the lepton number violating process. To prove the experiment feasibility, we are building a demonstrator module with 7 kg of 82Se, with an expected sensitivity of |mββ|<0.2÷0.4eV after 2.5y. The tracker, composed of 2034 drift cells operated in Geiger mode, is currently being assembled in the UK. The main challenge is the high radiopurity required to reduce the background. For this reason all components are carefully screened for radiopurity, the cell wiring is automated and every step of the tracker assembly happens in a clean environment. We review the detector design, and present the result of the Radon emanation measurement and of the surface commissioning of the first section of the tracker (504 drift cells).Speaker: Dr Michele Cascella (Università del Salento e INFN di Lecce)
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Design of a large area triple-GEM forward detector system based on industrially produced GEM foilsThe recently completed Forward GEM Tracker (FGT) of the STAR experiment at RHIC took advantage of commercially produced GEM foils based on double-mask chemical etching techniques. With future experiments proposing detectors that utilize very large-area GEM foils such as the CMS muon detector upgrade and a future Electron-Ion Collider facility, there is a need for commercially available large GEM foils. Double-mask etching techniques pose a clear limitation in the maximum size. In contrast, single-mask techniques developed at CERN would allow one to overcome those limitations. We report on results obtained using large GEM foils produced by Tech-Etch Inc. of Plymouth, MA, USA using single-mask techniques and thus the beginning for large GEM foil production on a commercial basis. A quality assurance procedure has been established through electrical and optical analyses via leakage current measurements and an automated high-resolution CCD scanner. The Tech-Etch foils show excellent optical performance and electrical properties with leakage currents typically measured below 1 nA. The design of a large novel triple-GEM forward detector system consisting of 12 30 degree sectors employing large single-mask produced GEM foils will be presented along with a detailed discus- sion of the excellent performance of large single-mask produced GEM foils manufactured on a commercial basis.Speaker: Prof. Bernd Surrow (Temple University)
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Determination of the anode wire position in a straw of the new type using visible lightMicroscope investigations of new-type thin-wall tubes (straws) produced for NA62 drift chambers revealed that they are semitransparent and allow anode wires to be observed under illumination by visible light. Positions of wires in straws and thus the anode spacing in the drift chamber can be directly determined with a high accuracy (~10 µ) using a microscope mounted on a precision optical bench. These data are important for decreasing errors during reconstruction of charged particle track coordinates in the drift chambers. The proposed method is much simpler than the X-ray or radioactive source methods.Speaker: Dr Levan Glonti (JINR)
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Test beam and irradiation test results of Triple-GEM detector prototypes for the Upgrade of the Muon System of the CMS experimentThe CMS Collaboration is evaluating Gas Electron Multiplier (GEM) chambers for the Upgrade of the High Eta region of the Muon System. Together with a rate capability fitting the extremely high particle rates expected in the forward regions, the use of GEM technology will lead to a significant improvement of tracking and triggering capabilities, muon identification and track reconstruction. The installation of a first GEM station is already foreseen during the 2nd LHC Long Shutdown (LS2), for joint operation with the existing Cathode Strip Chambers (CSC) stations. This contribution will review the status of the CMS GEM project, focusing on the R&D performed on chambers design features and readout electronics. Referring to the results of several test beams performed at the CERN SPS and at Fermilab in the last years, the performances of the upgraded detector will be discussed. In particular the response uniformity, the detection efficiency, the angular and spatial resolutions and the timing resolution as well as the performance in magnetic field have been measured with two different gas mixture (Ar/CO2 and Ar/CO2/CF4) using muon and pion beams.Speaker: Ilaria Vai (PV)
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Fibre Bragg Grating (FBG) sensors as flatness and mechanical stretching sensorsFibre Bragg Grating (FBG) sensors have been so far mainly used in high energy physics as high precision positioning and re-positioning sensor and as low cost, easy to mount and low space consuming temperature sensors. FBGs are also commonly used for very precise strain measurements. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide GEM foils of the GE1/1 chambers of the CMS experiment at LHC. The GE1/1 CMS upgrade consists of 144 GEM chambers of about 0.5 m^2 active area each and based on the triple GEMs technology, to be installed in the very forward region of the CMS endcap. The large active are of each GE1/1 chamber consists of a single GEM foil (the GE1/1 chambers represent the largest GEM foils assembled and operated so far) to be mechanically stretched in order to secure its flatness and the consequent uniform performance of the GE1/1 chamber across its whole active surface. A network of FBG sensors has been used to determine the optimal mechanical tension applied and to characterise the mechanical stress applied to the foils. The results of the test done on a full size GE1/1 final prototype and possible future developments will be discussed.Speaker: Luigi Benussi (LNF)
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High resolution timing for muon detectors at future collidersExperiments at present and future hadron colliders stress timing as one of the most important detector parameters. Indeed the need to increase the collider luminosity can be achieved in principle either by decreasing the inter-bunch crossing time or by increasing the number of protons per bunch. The latter approach however can produce a dramatic event pile-up in the same bunch crossing. We show here that high time resolution detectors can identify consecutive bunch crossings with time separation much below 1 ns. The performance of RPCs in the recent R&D development could match the requirements for future muon detectors. We discuss critically the limits and a possible upgrade of RPCs regarding the detector structure, the Front-End electronics and a new ecological gas mixture.Speaker: Roberto Cardarelli (ROMA2)
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Impact of the GE1/1 station on the performance of the muon system in CMSAfter the upgrades of the Large Hadron Collider planned for the second and the third Long Shutdown, the LHC luminosity will approach values like 2×1034 cm−2 s−1 and 5×1034 cm−2 s−1 respectively. Such conditions will deeply affect the performance of the CMS muon system, especially in the very forward region, due to the harsh expected background environment and the reduced magnetic field. The proposed GE1/1 upgrade consists in implementing an additional muon measurement station based on the Gas Electron Multipliers technology and covering the pseudorapidity region 1.6 < |η| < 2.2. Operating jointly with the existing Cathode Strip Chambers detectors, the GE1/1 station would ensure detection redundancy and would allow to maintain efficient triggering and good momentum resolution in the most critical region of the muon system. This presentation will review studies performed with different simulation tools to assess the capability of GEM detectors to operate in the expected radiation environment, the impact of GE1/1 on the muon trigger rate, on the quality of muon reconstruction and on the momentum resolution. Moreover, the benefits the GE1/1 system would bring to representative physics channels, both in the Standard Model and in the extended Higgs sector, will be discussed.Speaker: Alice Magnani (PV)
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MEG II drift chamber prototype characterisation with the silicon based cosmic ray tracker at INFN PisaHigh energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of many possible small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to be used as an external track reference. It consists in an assembly of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15-30~$\mathrm{\mu m}$. The DAQ originally used in the BaBar experiment was replaced by custom design boards coupled with an acquisition front-end PC through commercial FPGA evaluation boards. We present the performance in terms of tracking resolution and efficiency. A first device designed as a small prototype of the new drift chamber of the MEG II experiment has been characterised in many configurations. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He-Isobutane 85-15\%. The ionisation density in this gas admixture is of about 13 clusters/cm and an appreciable bias of the impact parameters for tracks crossing the cell close to the anode wire is predicted. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterisation the MEG II drift chamber prototype.Speaker: Luca Galli (PI)
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MRPC detector for MAMBO photonuclear experiment in BonnA MRPC detector should be installed in order to cover the forward angle in the MAMBO experiment in Bonn where is used as TOF detector located at 1 m from the target. This detector use four sealed stacks in order to reach time resolution of the order of 30-40 ps. First commissioning data is also showed.Speaker: Francesco Messi (Physikalisches Institut, Uni-Bonn)
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Optical readout of a Triple-GEM detector with a CMOS sensorIn last years, the development of optical sensors has produced objects able to provide very interesting performance. Large granularity is offered along with a very high sensitivity. CMOS sensors with millions of pixels able to detect as few as two or three photons per pixel are commercially available and can be used to read-out the optical signals provided by tracking particle detectors. In this work the results obtained by optically reading-out a triple-GEM detector by a commercial CMOS sensor will be presented. A standard detector was assembled with a transparent window below the third GEM allowing the light to get out. The detector is supplied with an Ar/CF$_4$ based gas mixture producing 650 nm wavelenght photons matching the maximum quantum efficiency of the sensor (about 80\%). In the presentation the measured performance as light yield, space resolution and detection efficiency will be shown.Speaker: Davide Pinci (ROMA1)
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Performance simulation studies for the ALICE TPC GEM UpgradeThe ALICE collaboration plans major upgrades to its detectors for run 3 and 4 of the LHC. For the TPC, the upgrade is aimed at increasing the rate capability to record an expected collision rate of 50 kHz Pb-Pb collisions, which requires continuous readout. The current TPC will therefore be reinstrumented with new Gas Electron Multipliers (GEM) readout chambers that can suppress ~99% of the ion back flow. The remaining 1% ion back flow will still give rise to significant space charge distortions that have to be corrected. In this poster I will show how these corrections are foreseen to be done and report the expected performance obtained from simulations studies. In order to understand the time dependence of the space charge distortions, a dynamic simulation has been developed. Results from these simulations will also be presented here.Speaker: Martin Ljunggren (Lund University)
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Precision Muon Tracking Detectors and Readout Electronics for Operation at Very High Background Rates at Future CollidersThe experience of the ATLAS muon spectrometer shows that drift-tube chambers provide highly reliable precision muon tracking over large areas. The ATLAS muon chambers are exposed to unprecedentedly high background of photons and neutrons induced by the proton collisions. Still higher background rates are expected at future high-energy and high-luminosity colliders beyond HL-LHC. Drift-tube detectors with 15 mm tube diameter (30 mm in ATLAS) and improved readout electronics optimized for high rate operation have been developed for such conditions. Tests at the Gamma Irradiation Facility at CERN showed that the rate capability is improved by more than an order of magnitude compared to the ATLAS chambers as space charge effects are strongly suppressed and operation with minimal electronics deadtime becomes possible. Studies of the new readout electronics will be discussed. Several full-scale chambers have been constructed with unprecedentedly high sense wire positioning accuracy of better than 10 micron. The chamber design and assembly methods have been optimized for large-scale production, reducing considerably cost and construction time while maintaining the high mechanical accuracy and reliability. Precise mounting of optical sensors with respect to the sense wires is essential for achieving the required accuracy of the chamber alignment system and is integral part of the assembly procedure.Speaker: Hubert Kroha (Max-Planck-Institut fuer Physik)
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Resistive Micromegas for sampling calorimetryMicromegas, as a proportional and compact gaseous detector, can be used as an active medium in a sampling calorimeter. Moreover, its readout plane can be finely segmented to perform Particle Flow reconstruction of jets at a future linear collider or high luminosity LHC experiment. For this application, sparks that would result from the potentially very large ionisation released in the gas during a shower can be avoided by means of resistive eletrodes. By slowing down the charge evacuation to ground through an RC-network, they allow a field reduction when the avalanche grows too large. While this mechanism efficiently quenches sparks, it might compromise the Micromegas intrinsic proportionality and the overall calorimeter response linearity. A study was conducted to determine the resistive configuration that best suppresses sparks and preserves proportionality. Several configurations were implemented on small prototypes, with a resistivity varying over five orders of magnitude. Charging of the resistive electrodes depends on the detector current, therefore the gain dependence on the rate and the dependence on the charge density (or dE/dx) were examined separately. Then, the spark quenching efficiency was assessed in a high intensity hadron beam used to generate showers that propagate through the prototypes. Our findings indicate that the resistivity necessary for quenching is surprisingly low, corresponding to an RC constant of the order of the avalanche time scale.Speaker: Dr maximilien chefdeville (CNRS/IN2P3/LAPP)
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Small-Strip Thin Gap Chambers for the Muon Spectrometer Upgrade of the ATLAS ExperimentFor the forthcoming upgrade to the LHC, the first station of the ATLAS muon end-cap system needs to be replaced in 2018 and 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase. In particular, the precision reconstruction of tracks requires a spatial resolution of about 100 um, and the Level-1 trigger track segments have to be reconstructed with an angular resolution of 1 mrad. The single sTGC planes of a quadruplet consists of an anode layer of 50um gold plated tungsten wire sandwiched between two resistive cathode layers. In order to benefit of the very good position resolution of the detectors, the position of each strip must be known with an accuracy of 40 μm along the precision coordinate and 80 um along the beam. The mechanical precision is a key point and must be controlled and monitored all along the process of construction and integration. A full size sTGC quadruplet has been constructed and equipped with the first prototype of dedicated front-end electronics. The performance of the sTGC quadruplet has been evaluated in test beams at Fermilab (May 2014) and CERN (October 2014), where the spatial resolution and trigger efficiencies were measured. We will present results obtained from the test beams and discuss the construction of a full size (~1x1m) sTGC quadruplet prototype.Speaker: Estel Perez (TRIUMF)
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Study of gain variation as a function of physical parameters of GEM foil using Garfield++Electron multiplication in Gas Electron Multipliers (GEM) occurs when primary electrons pass through the small holes where the electric field is very high. However the shape of the electric field distribution through the holes depends on the shape and size of the holes as well as the thickness of the polyimide foil. In consequence the local variation of these parameters results in the variation of gain over the whole area of the foil. Due to complications in the fabrication of the GEM foils, deviations from the design parameters over the entire area of the foil are not rare specially when large area foils are required to be fabricated. So an independent evaluation of the variation of gain as a function of the physical parameters is necessary for better operation of the detector. In this work we used Garfield++ simulation package to evaluate the gain for a GEM based detector and study the variation in it by changing the physical parameters around the standard values. Results from this study with single mask as well as double mask GEM foils will be presented.Speaker: Dr Supriya Das (Bose Institute)
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Study of mesh geometry impact on Micromegas performance with an Exchangeable Mesh prototypeThe fine, conductive meshes used in a Micromegas (MM) to divide drift and amplification regions contribute significantly to the signal formation processes. Systematic studies of the electron transparency and gain impact of different meshes in Micromegas are rare as in most MM applications the mesh is a fixed build-in component. An Exchangable Mesh Micromegas (ExMe) consisting of separated drift- and readout- panels and an easy to exchange mesh frame has been designed, built and tested at CERN. This provides the opportunity to study systematically the influence of different meshes keeping all other detector inherent parameters unchanged. Results from these studies will be presented, including comparison of the experimental data with advanced microscopic simulations carried out in Garfield++.Speaker: Mr Fabian Kuger (CERN / University of Würzburg)
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Systematic measurements of gain and energy resolution of single and double mask GEM detectorsTriple GEM’s will be used to instrument the CBM muon detector MUCH (MUon CHamber). In the GSI detector laboratory an R and D effort has been performed to study the characteristics of both single and double mask GEM detectors. In this study, the gain and the energy resolution have been measured systematically employing an 55Fe source as a function of the voltages applied to the GEM foils. It has been observed that for very low and very high drift voltage the gain is somewhat reduced, while it is nearly constant at the intermediate values. In case of other voltage variations such as the induction and transfer voltages, it has been observed that the gain increases with the voltage and saturates at some point. The results of the systematic measurements will be presented.Speaker: Dr Saikat Biswas (National Institute of Science Education and Research)
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The drift chamber with a new type of straws for operation in vacuumA 2150x2150 mm2 registration area drift chamber capable of working in vacuum is presented. Thin-wall tubes (straws) of a new type are used in the chamber. A large share of these 9.80 mm diameter drift tubes are made at Dubna from the metalized 36 µm Mylar film welded along the generatrix using the ultrasonic welding machine created at JINR. The main features of the chamber and some characteristics of the drift tubes are described. Four such chambers with the X, Y, U, V coordinates each, containing 7168 straws in total, are designed and produced at JINR and CERN. They are installed in the vacuum volume of the NA62 set-up to study the ultra-rare decay and to search for and study rare meson decays. In autumn 2014 the chambers were the first used for the data-taking in the experimental run of the NA62 at CERN's SPS.Speaker: Dr Yury Potrebenikov (JINR, Dubna)
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Tripple-stack Resistive Plate Chamber with Strip Readout for Particles Identification in the BM@N and MPD Experiments.The new full-scale prototype of the ToF detector for BM@N and MPD experiments was produced and tested. First time we use three stacks of glasses to make symmetrical construction to decrease dispersion and reflections of the sygnal on the long readout strip.Speaker: Mr Vadim Babkin (Joint Institute for Nuclear Research)
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Upgrades of the ATLAS Muon Spectrometer with sMDT ChambersThe Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer demonstrated that they provide very precise and robust tracking over large areas. Goals of ATLAS muon detector upgrades are to increase the acceptance for precision muon momentum measurement and triggering and to improve the rate capability of the muon chambers in the high-background regions when the LHC luminosity increases. Small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages with the MDTs, but have more than ten times higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, reducing cost and construction time considerably and improving the sense wire positioning accuracy to better than ten microns. Two sMDT chambers have been installed in 2014 to improve the momentum resolution in the barrel part of the spectrometer. The construction of twelve chambers for the feet regions of the ATLAS detector has started. A just recently approved project foresees the replacement of the MDT chambers at the ends of the inner barrel detector layer with sMDTs making space for additional RPC trigger chambers and improving the rate performance. Design, construction and installation of the new sMDT chambers for ATLAS will be discussed as well as tests of their performance.Speaker: Dr Claudio Ferretti (University of Michigan)
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A Cylindrical GEM Detector with Analog Readout for the BESIII ExperimentWe are developing a cylindrical GEM detector with analog readout to upgrade the Inner Tracker of the BESIII experiment at IHEP (Beijing). The new detector will match the requirements for momentum resolution (σpt/Pt ~0.5% at 1 GeV) and radial resolution (σxy ~100μm) of the existing drift chamber and will improve significantly the spatial resolution along the beam direction (σz ~150μm) with very small material budget (about 1% of X0). With respect to the state of the art the following innovations will be deployed: a lighter mechanical structure based on Rohacell, a new XV anode readout plane with jagged strip layout to reduce the parasitic capacitance, and the use of the analogue readout inside a high intensity magnetic field to have good spatial resolution without increasing the number of channels. A beam test has been performed at CERN in order to measure the performance of a BESIII GEM prototype in a magnetic field up to 1 Tesla. An overview of the project and the preliminary results of the test among with a comparison with detailed Garfield simulations will be presented in the talk. The project has been recognised as a Significant Research Project within the Executive Programme for Scientific and Technological Cooperation between Italy and P.R.C. for the years 2013-2015, and more recently has been selected as one of the project funded by the European Commission within the call H2020-MSCA-RISE-2014.Speaker: Marco Maggiora (TO)
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Ageing tests for the MEG II drift chamberThe MEG II experiment will search for the Lepton-Flavour-Violating decay of $\mu \to e \gamma$ with an expected sensitivity on the branching ratio of about 5$\times 10^{-14}$, ten times better than MEG. In MEG II Michel positrons will be tracked by a single-volume cylindrical drift chamber, composed of 10 criss-crossing sense wire planes with alternating stereo angles of about $7^\circ$. The elementary drift cell is approximately squared with a width of about 7 mm. The chamber is filled with an ultra-low mass gas mixture of helium and isobutane 85:15. Since the detector will be subject to a very high flux of Michel positrons, it is necessary to probe the robustness of the chamber to huge amounts of accumulated charge (up to 0.5 C/cm in the expected data taking period). For this reason, laboratory tests were performed on small size drift chamber prototypes. Accelerated charge collection was induced by X-ray tubes illuminating selected portions of the wires. As an indicator of the ageing of the chamber, gain loss was monitored. Special attention was paid in considering gain variations that can arise from changes of the environmental conditions (e.g. gas temperature) and from space charge effects. At the end of the test, aged wires were inspected with Scanning Electron Microscopy and Energy Dispersive X-ray analysis.Speaker: Mr Marco Venturini (PI)
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Protonated water clusters in TPC detectorWhether intentionally or as contaminant, water is present in many gas-based detectors,owing to its low ionisation potential ($12.52~\mathrm{eV}$), water is ionised both by electron impact and by charge transfer.Ionised water reacts with neutral water molecules to form $\mathrm{H}_3\mathrm{O}^+$ hydronium ions which combine with further water molecules to form large $\mathrm{H}^+ \cdot (\mathrm{H}_2\mathrm{O})_n$ clusters.Hydronium ions also combine with $\mathrm{CO}_2$ molecules into mixed clusters. These clusters are heavier and hence slower than the primary ions.This may lead to an increased dwelling time in large devices like TPCs where they increase the amount of space charge. Additionally, the signal shape will be modified. Therefore, it is important to determine the size distribution of protonated water clusters, not only at low pressure and temperature where most of the earlier experiments have been performed, but also under the conditions that prevail in detectors: atmospheric pressure and room temperature. Here, we perform a theoretical study of the reaction $\mathrm{H}_3\mathrm{O} + (\mathrm{H}_2\mathrm{O})_{n-1} + \mathrm{H}_2\mathrm{O} \leftrightarrow \mathrm{H}_3\mathrm{O} + (\mathrm{H}_2\mathrm{O})_n$ ($n = 1 \mbox{-} 9$) in the gas phase. We calculate the molecular structure and the vibration frequencies of protonated water clusters in the ground state using computational quantum mechanical modeling. The calculated equilibrium constants $K_{n-1,n}$ agree with experimental data from literature.Speaker: Dr Yunus KAYA (Uludag University)
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Solid State DetectorsConveners: Dr Anthony Affolder (University of Liverpool), Dr Frank Hartmann (IEKP Karlsruhe)
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The LHCb VELO UpgradeThe upgrade of the LHCb experiment, planned for 2018, will transform the experiment to a trigger-less system reading out the full detector at 40 MHz event rate. All data reduction algorithms will be executed in a high-level software farm. The upgraded detector will run at luminosities of 2 x 10^33 /cm^2/s and probe physics beyond the Standard Model in the heavy flavour sector with unprecedented precision. The Vertex Locator (VELO) is the silicon vertex detector surrounding the interaction region. The current detector will be replaced with a hybrid pixel system equipped with electronics capable of reading out at 40 MHz. The detector comprises silicon pixel sensors with 55x55 um^2 pitch, read out by the VeloPix ASIC, from the TimePix/MediPix family. The hottest region will have pixel hit rates of 900 Mhits/s yielding a total data rate more than 3 Tbit/s for the upgraded VELO. The detector modules are located in a separate vacuum, separated from the beam vacuum by a thin custom made foil. The detector halves are retracted when the beams are injected and closed at stable beams, positioning the first sensitive pixel at 5.1 mm from the beams. The material budget will be minimised by the use of evaporative CO_2 coolant circulating in microchannels within 400 um thick silicon substrates. The current status of the VELO upgrade will be described and latest results from irradiated sensor assemblies will be presented.Speaker: Mr Álvaro Dosil (Universidade de Santiago de Compostela)
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ALPIDE, the Monolithic Active Pixel Sensor for the ALICE ITS upgradeA new Inner Tracking System based on seven concentric layers of Monolithic Active Pixel Sensors will be installed in the ALICE experiment during the second long shutdown of LHC in 2018-2019. It is based on 10m^2 of pixel sensors that will be fabricated using the 180nm CMOS Imaging process of TowerJazz. The ALPIDE design takes full advantage of a particular process feature, the deep p-well, which allows for CMOS circuitry within the pixel matrix, while retaining the full charge collection efficiency. Together with the small structure size, this allowed placing a continuously active, low-power front-end into each pixel and using an in-matrix sparsification circuit that sends only the addresses of hit pixels to the periphery. This approach led to a design with a power consumption of <40mW/cm^2, a spatial resolution of ~5um, and a peaking time of ~2us, while being radiation hard to some 10^3 1MeV n-eq, perfectly matching or superseding the requirements of ALICE. Over the last years of R&D, several prototype circuits have been used to verify radiation hardness and to optimise pixel geometry and in-pixel front-end circuitry. The positive results led to submissions of full-scale (3x1.5 cm^2) sensor prototypes in 2014. They are being characterised in a thorough campaign that includes several irradiation and beam tests. This contribution will give a comprehensive summary of the results obtained and prospects towards the final sensor to instrument the ALICE Inner Tracking System.Speaker: Dr Magnus Mager (CERN)
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The ATLAS Upgrade Planar Pixel Sensors R&D Project: Status and OverviewTo investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Planar Pixel Sensor R&D Project was established comprising 18 institutes and more than 80 scientists. Main areas of research are • performance assessment of planar pixel sensors at HL-LHC fluences to drive design and process improvements. • establishment of reliable device simulations for severely radiation-damaged pixel detectors • the exploration of possibilities for cost reduction to enable the instrumentation of large areas with pixel detectors The presentation will give an overview of the most recent achievements of the R&D project, among them • beam test results with planar sensors irradiated up to HL-LHC fluences at different eta angles providing new insight into efficiencies and cluster sizes under realistic b-layer conditions • measurements obtained with irradiated n-in-p pixel assemblies of different thicknesses down to 100 µm and with special active/slim edges • comparisons of these experimental findings with initial TCAD device simulations • update on prototyping efforts for large areas: sensor design improvements, 6” wafer production yields, characterisations and rad-hardness confirmations. On the base of these results, a discussion on the possible ways implementing planar pixel sensors in the different layers of the new ATLAS pixel system will be given.Speaker: Dr Paul Dervan (University of Liverpool)
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CMS Tracker Upgrade for HL-LHC: R&D Plans, Present Status and PerspectivesDuring the high luminosity phase of the LHC (HL-LHC), the machine is expected to deliver an instantaneous luminosity of 5 x 10^34 cm^-2 s^-1. A total of 3000 fb^-1 of data is foreseen to be delivered, with the opening of new physics potential for the LHC experiments, but also new challenges from the point of view of both detector and electronics capabilities and radiation hardness. In order to maintain its physics reach, CMS will build a new Tracker, comprising completely new pixel detector and outer tracker. The ongoing R&D activities on both pixel and strip sensors will be presented. The present status of the Inner and Outer Tracker projects will be illustrated, and the possible perspectives will be discussed.Speaker: Fabio Ravera (TO)
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Investigation of radiation effects on Si cryogenic detectors in the framework of CERN-RD39 collaboration program and LHC upgradeThe superconducting magnets of the Large Hadron Collider (LHC) located close (within a few tens of meters) to the Interaction Points of the proton beams are exposed to high-radiation fields due to the collision debris. The Beam Loss Monitoring (BLM) system measures the particle showers from beam losses. Due to the foreseen increase in the LHC luminosity, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the ongoing CERN-RD39 research efforts of the development of the new BLM system based on semiconductor detectors. They will be located as close as possible to the superconducting coils of the triplet magnets, meaning that the BLM will be immersed in superfluid helium inside the cold mass and operate at 1.9 K, with expected irradiation tolerance of 1x10^16 proton/cm2. The overview of the activities aimed on testing silicon and diamond detectors in the conditions of their operation as BLMs (in situ irradiation by 23 GeV protons at 1.9 K) and the status of the experiment are described. The results of the study have been used for the development of the pilot BLM modules currently installed on the magnets in the area with high debris intensity.Speaker: Prof. Zheng Li (School of Nuclear Engineering and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, China)
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The Silicon Vertex Detector of the Belle-II ExperimentThe Belle-II experiment will exploit the very high luminosity planned at the SuperKEKB flavor factory at KEK to perform many precision measurements and to search for new physics beyond the Standard Model. The high precision tracking system is composed of a two-layer DEPFET pixel detector (PXD), a four-layer double-sided silicon strip detector (SVD) and a central drift chamber (DCH). To maintain the required performance for low momentum tracking and vertexing, the SVD employs several innovative techniques: strip signals with a total of 200k channels are readout by about 5,000 APV25 ASICs mounted directly on the ladder with the novel Origami technique in order to minimize the signal path and the consequent capacitive noise; active evaporative cooling is used, with pipes directly in contact with the chip surface; the detector ladders have a lampshade geometry to minimize material in the forward direction. The Belle-II SVD design and prototype has been completed, and it is now in construction stage. The installation on the Belle-II detector is foreseen in 2017. In this paper, the design principles and construction status of the Belle-II SVD will be presented, together with some results from the beam tests performed.Speakers: Francesco Forti (PI), Ms Tomoko Morii (University of Tokyo Kavli IPMU (WPI))
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10:30 AM
Coffee Break
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RD50 Collaboration Overview: Development of New Radiation Hard DetectorsRD50 is a CERN R&D collaboration dedicated to the development of radiation hard semiconductor devices for application in high luminosity colliders. It is based on four pillars: Defect and Material Characterization; Detector Characterization; Development of New Structures; Full Detector Systems. Its ultimate goal is to develop radiation hard devices that can cope with a fluence of 2x106 neq/cm2, to be applied for the high- luminosity LHC runs. This factor 10 increase in fluence requires both material and device engineering. A number of new technologies are developed within RD50. This presentation will report on the following topics: • 3D devices, which have columnar implants across the bulk so that depletion region grow sideways instead of vertically. They are characterized by low depletion voltage. • CMOS pixels in HV technology, built on low resistivity p-type silicon. These detectors, characterized by an n-well deeper than the one normally used in CMOS monolithic active pixels (MAP’s), are expected to be more radiation hard. • Low Gain Avalanche Detectors (LGAD’s): diodes realized with this technology exploit the avalanche multiplication mechanism in order to generate a moderate and controlled gain. These devices can be read-out by the same electronics used for non-multiplying diodes. Thinner substrates can also enhance their time resolution, thus opening up to various applications. Both pixels and strips are targets for this technology.Speaker: Dr Susanne Kuehn (Albert-Luwigs-University Freiburg)
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Design, Fabrication and Characterization of multi-guardring-furnished p+n Silicon Strip Detectors for future HEP experimentsSi detectors, in various configurations (strips & pixels etc), have been playing a key role in High Energy Physics (HEP) experiments owing to their excellent vertexing and high precision tracking information. In future HEP experiments like upgrade of Compact Muon Solenoid experiment at the Large Hadron Collider, CERN & the proposed International Linear Collider, the silicon tracking detectors will be operated at very harsh radiation environment, which lead to both surface and bulk damage in silicon detectors which in turn changes their electrical properties, i.e. change in full depletion voltage, increase in the leakage current & decrease in the charge collection efficiency. In order to achieve the long term durability of Si-detectors in future HEP experiments, it is required to operate these detectors at very high reverse biases, beyond the full depletion voltage thus requiring higher detector breakdown voltage. Delhi University (DU) is involved in the design, fabrication and characterization of multi-guard-ring furnished ac-coupled, single sided, p+n silicon strip detectors for future HEP experiments. The design has been optimized using a two-dimensional numerical device simulation program (ATLAS-Silvaco). The Si strip detectors are fabricated with eight-layer mask process using the planar fabrication technology by Bharat Electronic Lab (BEL), INDIA. Further an electrical characterization set-up is established at DU to ensure the quality performance of fabricated Si strip detectors and test structures. In this work measurement results on non irradiated Si Strip detectors and test structures with multi-guard-rings using Current Voltage (IV) and Capacitance Voltage (CV) characterization set-ups are discussed. The effect of various design parameters, for example guard-ring spacing, number of guard-rings and metal overhang on breakdown voltage of Si strip detectors have been studied.Speaker: Dr Kavita Lalwani (University of Delhi, INDIA)
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Advanced monolithic pixel sensors using SOI technologyWe are developing monolithic pixel detectors using 0.2 um FD-SOI pixel process. It aims at developing the next generation pixel detector for the future high energy physics experiment, space application, material science, medical application and so on. An SOI wafer is utilized for sensor and electronics. The top silicon is used for SOI-CMOS circuit, and the substrate is used for a radiation sensor. There is a buried oxide layer between two silicon materials, and these are connected each other through Tungsten via. SOI-CMOS circuit has smaller parasitic capacitance compared with bulk CMOS, and therefore high-speed, low noise and low power circuits can be fabricated. Since a bump bonding is not used, the sensors have high gain with smaller pixel size. SOI wafers are fabricated from two silicon wafers using Smart Cut™ by SOITEC. We have applied several types of wafers for the substrate, Czochralski (CZ), float-zone (n- and p- type FZ), and double SOI. KEK has performed the development project since 2005 and organizes Multi Project Wafer (MPW) runs once or twice a year and many universities and institution all over the world are participating. Several types of integration-type pixel sensor and counting-type pixel sensor have been developed with the pixel size of 8-64 microns. The characteristics of the detectors were investigated using radiation sources, X-rays and high-energy charged particles. In this presentation, recent progress and status of the development will be shown.Speaker: Dr Toshinobu Miyoshi (KEK)
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Depleted CMOS pixels for LHC pp-ExperimentsWhile so far monolithic pixel detectors have remained in the realm of comparatively low radiation application outside LHC, new developments exploiting high resistivity substrates with three or four well CMOS process options allow fairly large depletion depths and full CMOS circuitry in a monolithic structure. This opens up the possibility to target CMOS pixel detectors also for high radiation pp-experiments at the LHC upgrade, either in a hybrid-type fashion or even fully monolithic. We have prototyped several pixel matrices with high ohmic substrates and full CMOS electronics and characterized them in the lab and in test beams. On the basis of this an ATLAS CMOS demonstrator program has been started. The results available at the time of the meeting will be presented.Speaker: Prof. Norbert Wermes (University of Bonn)
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The INFN-FBK “Phase-2” R&D ProgramWe report on the 3-year INFN ATLAS-CMS joint research activity in collaboration with FBK, started in 2014, aimed at the development of new pixel detectors for the LHC Phase-2 upgrades (aka HL-LHC). The latter will need the complete replacement of the ATLAS and CMS inner trackers with new ones fulfilling the requirements of a higher radiation fluence (2x10^16 neq/cm^2 , or equivalently 1 Grad, expected on the inner pixel layer for 2500 fb^-1 integrated luminosity in the Phase-2), higher event pile-up (140 events/bunch-crossing). To maintain the same performance of the present detector systems a new generation of technologies has to be fully exploited for the redesigned Pixel detectors. Among them the future version of front-end chips in 65-nm CMOS by the CERN RD53 Collaboration will allow for smaller pixel sizes (50x50 or 25x100 um^2) and lower thresholds (~1000 e). The advances in the front-end design shall require sensors with smaller pixel cells and thinner active thickness to match the reduced pixel dimension and to improve track resolution and cluster separation in higher pile-up environment. Additional optimization of the new Pixel detector requires the reduction of the radiation-length of the layer to minimize secondary interactions and Multiple Coulomb Scattering effects. To this purpose, a new generation of 3D sensors and of planar sensors with active edges are being developed in the project and will be fabricated at the pilot line of FBK, that was recently updated to 6-inch wafers. Another partnership is in place with Selex for further developing Indium bump-bonding technology, that is potentially more suited than solder-reflow for large chip sizes, thinner electronic and sensor substrates due to the lower temperature of the process (90 ºC instead of 250 ºC). The talk will cover the main aspects of the research program, from the sensor design and simulation, to the fabrication technology, to the results of initial tests performed of the first prototypes.Speaker: Prof. Gian Franco Dalla Betta (University of Trento)
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A 3D Diamond Detector for Particle TrackingA novel detector using single-crystal chemical vapor deposited diamond and resistive electrodes in the bulk forming a 3D diamond detector is presented. The electrodes of the device were fabricated with laser assisted phase change of diamond into a combination of diamond like carbon, amorphous carbon and graphite. The connections to the electrode of the prototype device were made using a photo-lithographic process. The electrical and particle detection properties of the prototype device were investigated. A prototype detector system consisting of the prototype 3D device connected to a multi-channel readout was successfully tested with 120 GeV protons proving the feasibility of the 3D diamond detector concept for particle tracking applications.Speaker: Lars Graber (II. Physikalisches Institut, Universität Göttingen)
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Solid State Detectors - Poster Session
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A direction sensitive sapphire detector for single particle detectionA multichannel detector designed for single minimum ionising particle detection using a stack of sapphire plates is presented. The performance of the detector was studied in a 5 GeV electron beam at DESY-II. The detector was operated together with the EUDET beam telescope, which allowed the reconstruction of the position of the impact point at the detector. For each sapphire plate the charge collection efficiency was measured as a function of the bias voltage and the signal size as a function of the hit position with respect to the metal electrodes. The charge collection efficiency rises with the voltage, reaching about 10% at 950V. Also evidence for the presence of a polarization field was observed. The data confirms the prediction that mainly electrons contribute to the signal. Based on these results the next generation sapphire detector will be designedSpeaker: Olena Karacheban (DESY/BTU)
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A new on-line luminometer and beam conditions monitor using single crystal diamond sensorsInstrumentation near the beam-pipe requires extremely radiation hard sensors. Inside CMS two rings instrumented with 12 single crystal diamond sensors each are installed on both sides of the interaction point. The sensors are subdivided in two pads, and each pad is read out by a dedicated fast radiation hard ASIC in 130 nm CMOS technology. Due to the excellent time resolution collision products will be separated from machine induced background. In the backend a dead-time less histogramming unit is used, and a fast micro TCA system with GHz sampling rate is under development. The detector will measure both the on-line luminosity and the background bunch-by-bunch. The performance of a prototype detector in a test-beam will be reported, and results from the operation during data taking will be presented.Speaker: Ms Olena Karacheban (PhD BTU Cottus, DESY-Zeuthen)
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Belle-II SVD ladder assembly proceduresThe Belle-II experiment at the SuperKEKB collider in Japan will operate at a luminosity approximately 50 times greater than its predecessor (Belle). At its heart lies a six-layer vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle-II is time-dependent CP violation asymmetry, which hinges on a precise charged-track vertex determination. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the jigs used in assembly as well as of the final SVD modules.Speaker: Mr Varghese Babu (Tata Institute of Fundamental Research)
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Belle-II VXD radiation monitoring and beam abort with scCVD diamond sensors.The Belle-II VerteX Detector has been designed to improve the performances with respect to Belle and to cope with the unprecedented luminosity of 8x10^35 cm-2s-1 achievable by SUPERKEKB. Special care is needed to monitor both the radiation dose accumulated through the life of the experiment and the instantaneous radiation rate, in order to be able to react quickly to sudden spikes for the purpose of protecting the detectors. A radiation monitoring and beam abort system based on single-crystal diamond sensors is now under development for the VXD. The sensors will be placed in several key positions in the vicinity of the interaction region. The severe space limitations require a challenging remote readout of the sensors. The system design will be described, along with the sensor characterization procedure and the design of the readout electronics.Speaker: Lorenzo Vitale (TS)
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CLIC vertex detector R&DA vertex detector is under development for CLIC, a future linear electron—positron collider with a maximum centre of mass energy of 3 TeV. In order to perform precision physics measurements in a challenging environment, the CLIC vertex detector must have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low mass, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations, together with the beam structure of CLIC, push the technological requirements to the limits. A detector concept based on hybrid pixel-detector technology is under development. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin (50 um) planar or active HV-CMOS sensors via low-mass interconnects. Prototype devices have been tested in the lab and with beams. The power dissipation of the readout chips is drastically reduced by means of power pulsing, allowing for a low-mass cooling system based on forced air flow through an optimised arrangement of detection layers. This talk reviews the requirements and design optimisation for the CLIC vertex detector and gives an overview of recent R&D achievements in the domains of cooling, supports, powering, detector integration, sensors and readout. First results with an innovative hybridisation concept based on capacitive coupling between active sensors and readout ASICs will be presented.Speaker: Niloufar Alipour Tehrani (ETH Zürich, CERN)
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CO2 evaporative cooling: the future for tracking detector thermal managementIn the last few years, CO2 evaporative cooling has been one of the favourite technologies chosen for the thermal management of tracking detectors at LHC. ATLAS Insertable B-Layer and CMS Phase I Pixel have adopted it and their systems are now operational or under commissioning. The CERN PH-DT team is now merging the lessons learnt on these two systems in order to prepare the design and construction of the cooling systems for the new Upstream Tracker and the Velo upgrade in LHCb, due by 2018. Meanwhile, the preliminary design of the ATLAS and CMS full tracker upgrades is started, and both concepts heavily rely on CO2 evaporative cooling. This paper highlights the performances of the systems now in operation and the challenges to overcome in order to scale them up to the requirements of the future generations of trackers. In particular, it focuses on the conceptual design of a new cooling system suited for the large phase2 upgrade programmes, which will be validated with the construction of a common prototype in the next years.Speaker: Paola Tropea (CERN)
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Characterization of Depleted Monolithic Active Pixel Detectors with High-Resistive CMOS TechnologyWe present the recent development of Depleted Monolithic Active Pixel Sensors (DMAPS), implemented with a Toshiba 130~nm CMOS process. Recent progress in CMOS technology enables to utilize a high-resistive silicon substrate as a charge sensitive layer and to fabricate CMOS electronics inside of nested-wells in the same substate. Such technology offers truly monolithic devices as an alternative to hybrid detectors or charge coupled devices, and, hence, possibility of DMAPS with various technology is currently under intensive study. Compared to the conventional epi layer-based MAPS, DMAPS have several merits as charge-measurement detectors: since the substrate can be operated as a fully depleted bulk, the charge collection becomes faster and larger signal is available for signal processing. As a result, the radiation tolerance is expected to be much higher than the conventional MAPS detectors. In order to characterize the technology, we implemented a simple three transistor readout with a variety of collection electrode's layouts. This layout variety gives us a clue on sensor characteristics for future optimization, such as the input detector capacitance or leakage current. In the presentation, we will show initial measurement results on the sensor and discuss the future perspective by comparing other DMAPS implementation based on different CMOS technologies.Speaker: Dr Tetsuichi Kishishita (University of Bonn)
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Characterization of Si Detectors through TCT Technique at Delhi UniversityTransient Current Technique (TCT) is one of the important methods to characterize Silicon (Si) detectors and is based on the time evolution of the charge carriers generated when a laser light is shone on it. For red laser, charge is injected only to a small distance from the surface of the detector. For such a system, one of the charge carriers is collected faster than the readout time of the electronics and therefore, the effective signal at the electrodes is decided by the charge carriers that traverse throughout the active volume of the detector, giving insight to the electric field profile, drift velocity, effective doping density, etc. of the detector. Delhi University is actively involved in the Si detector R&D and has recently installed a TCT setup consisting of a red laser system, a metal box, a SMU (Source Measuring Unit), a bias tee, and an amplifier. Measurements on a few Si pad detectors have been performed using the developed system, and the results have been found in good agreement with the CERN setup.Speaker: Ms Geetika Jain (Delhi University)
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Charge collection studies of neutron irradiated double sided silicon strip detectors for double metallization or cable interconnections for the end stripsThe Compressed Baryonic Matter (CBM) experiment is one of the major scientific pillars at FAIR at Darmstadt, Germany which aims to explore the QCD phase diagram in the regions of high net baryon densities and moderate temperatures. The Silicon Tracking System (STS), the core detector of the CBM experiment, is located in the dipole magnet to provide track reconstruction and momentum determination of charged particles from beam-target interactions. The STS will be populated with about 1300 double-sided silicon microstrip detectors (DSSDs) mounted onto a low-mass carbon fiber support structures. The strips on one side of the DSSDs are tilted to have 7.50 stereo angle. This allows to reconstruct multiple hits from the same detector at the expense of a poorer spatial resolution in vertical direction. To have read out only from one detector side, the end strips from one edge of the detector were connected to the end strips on the other edge. This interconnection can be provided via double metallization or by using external interstrip cables. The prototype detectors (with double metallization or with external cables) were irradiated to neutron equivalent fluences of 2×1014 neqcm−2, as they are expected for the worst case scenario in the CBM experiment. These detectors were tested for the leakage current, capaciatance variation with bias voltage and for charge collection. Test results from these prototype sensors both before and after irradiations will be presented.Speaker: Dr Minni Singla (GSI Darmstadt)
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Design Optimization of Pixel sensors using device simulations for Phase-II CMS tracker upgradeIn order to address the problems caused by harsh radiation environment during the high luminosity phase of the LHC (HL-LHC), all Si tracking detectors (pixels and strips) in the CMS experiment will undergo an upgrade. In order to develop radiation hard pixel sensors, simulations have been performed using 2D TCAD device simulators, SILVACO and SYNOPSYS, to obtain design parameters. Simulations are carried out on two n+p- planar pixel sensor geometries; 50 micron x 50 micron and 100 micron x 25 micron, each for two wafer thickness of 150 micron and 200 micron. Each geometry has two configurations, which are referred as “normal” and “wide” having different implant widths. To achieve the isolation between the n+ pixels, simulations are performed for both p-stop and p-spray techniques. The effect of various design parameters like pixel size, pixel depth, implant width, metal overhang, p-stop concentration, p-stop depth and bulk doping density, on leakage current and critical electric field, are carried out for both non-irradiated as well as irradiated pixel sensors. The simulation of non-irradiated pixel sensors are performed by incorporating the fixed oxide charge density (QF) of 1e11cm^(-2) and two interface traps at Si/SiO2 interface (Nit). Irradiated pixel sensors are simulated by implementing two bulk trap levels along with appropriate values of QF and Nit for different fluences considering the level of radiation damage to pixel sensors in HL-LHC scenario. These 2D simulation results of planar pixels are useful in providing an insight of the non-irradiated and irradiated Si pixel sensors and further work on 3D simulation is underway.Speaker: Dr K. Lalwani (University of Delhi)
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Design and TCAD simulation of planar p-on-n active-edge pixel sensors for the next generation of FELsFuture experiments at the European X-Ray Free Electron Laser (XFEL) will require silicon pixel sensors with demanding performance: a wide dynamic range from 1 up to 10^4 12-keV photons per pixel, a small pixel pitch (~100 μm), minimum dead area and a radiation tolerance of 1GGy per 3 years of operation. Therefore, the development of four-side buttable tile detectors that meet such requirements is challenging. Through this work, carried out in the framework of the PixFEL project, design and TCAD simulations of planar p-on-n sensors with an active edge approach are performed with the aim of minimizing the dead area at the edge. The improvement of the breakdown characteristics in order to reach at least the minimum bias voltage required to avoid plasma effects at high charge concentration is achieved using different edge borders or layouts with the incorporation of multiple guard rings at the edge. The methodology of the sensor design, the optimization of the most relevant parameters, and the optimized layout are described. Finally, the simulated performance, in particular the breakdown voltage and the charge collection properties are presented.Speaker: Prof. Gian Franco Dalla Betta (University of Trento)
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Developing Silicon Strip Detectors with a large-scale commercial foundrySilicon-based sensors are well established as tracking devices in modern particle detectors. The high spatial resolution and the comparable low costs make them best suited for large scale applications like the CMS Tracker. However, the required quantities often exceed the capabilities of academic institutions and therefore commercial vendors are assigned with the production. Since 2009 the Institute of High Energy Physics (HEPHY) in Vienna is developing a production process for planar silicon strip sensors on 6 inch wafers with the semiconductor manufacturer Infineon. Up to now, four runs with several batches of wafers, each comprising six different sensors, were manufactured and characterized. The next project milestone will be sensors produced on 8 inch p-type wafers. A summary of the 6 inch campaign will be given in this talk. The focus will be on a defect most of the sensors show, which caused an area of defective strips. Techniques to cure affected sensors as well as the evocation of the defective area at the manufacturer and in the laboratory will be discussed. Along with results from electrical characterization, results gained from beam tests at the SPS at CERN will be presented.Speaker: Mr Axel König (HEPHY Vienna)
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Development of a New Generation of 3D Pixel Sensors for HL-LHCWe report on the development of a new generation of 3D pixel sensors for the High-Luminosity LHC (HL-LHC) within the framework of the INFN-FBK “Phase 2” R&D program. In the first year of the project, the sensor technology and design have been optimized for increased pixel granularity (e.g., 25x100 or 50x50 um^2 pixel size), extreme radiation hardness (up to a fluence of 2x10^16 neq cm^-2), reduced material budget and better geometrical efficiency. Compared to the double-sided 3D sensors successfully produced at FBK for the ATLAS IBL, these requirements called for a modified (single-sided) technology allowing for thinner sensors (~100 um), narrower electrodes (~ 5 um), reduced electrode spacing (~ 30 um), and very slim (~ 50 um) or active edges. Moreover, pixel designs compatible both with present (for testing) and future (RD53 65- nm CMOS) read-out chips of ATLAS and CMS are necessary. The paper will cover aspects relevant to the main technological steps being developed (e.g., Deep Reactive Ion Etching of narrow columnar electrodes and filling of the same with poly-Si) and to the design, TCAD simulation and layout of the first batch of these new 3D sensors to be fabricated at FBK on 6-inch wafers.Speaker: Mr Maurizio Boscardin (FBK)
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Development of arrays of Silicon Drift Detectors and readout ASICs for the SIDDHARTA experimentThis work deals with the development of new Silicon Drift Detector (SDDs) and readout electronics for the upgrade of the INFN-SIDDHARTA experiment. The SIDDHARTA experiment performs a high resolution X-ray spectroscopy measurement of kaonic atoms transitions to determine the strong interaction induced shift and width of the lowest experimentally accessible level. The detector under construction is based on a SDDs array organized in a 4×2 format with each SDD square shaped with 64 mm2 (8×8) active area, for a total area of 34×18 mm2. The SIDDHARTA apparatus requires 48 of these modules, designed and manufactured by Fondazione Bruno Kessler (FBK). The readout electronics is composed by CMOS preamplifiers (CUBEs) and by the new SFERA (SDDs Front-End Readout ASIC) circuit, which is here presented for the first time. SFERA is a 16-channels readout ASIC designed in a 0.35 µm CMOS technology, which features in each single readout channel a high order shaping amplifier (9th order Semi-Gaussian complex-conjugate poles) and a high efficiency pile-up rejection logic. The outputs of the channels are connected to an analog multiplexer for the external analog to digital conversion. An on-chip 12-bit SAR ADC is also available. Preliminary measurements of the detectors in the single and in the array format will be reported. Also measurements of low X-ray energies will be reported in order to prove the possible extension of the soft X-ray range for applications in synchrotron beam lines.Speaker: Filippo Schembari (MI)
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Development of radiation hard CMOS Active Pixel Sensors for HL-LHCThe luminosity of the Large Hadron Collider (LHC) will increase nearly by an order of magnitude over its design luminosity during the HL-LHC upgrade with the goal to substantially enhance the sensitivity of its experiments to rare processes. The present ATLAS tracker, called Inner Detector, will be replaced with a newly developed tracker, which can cope with the expected high radiation damage, the high hit rates, stringent tracking requirements and the pile-up of >140 collisions per bunch crossing of LHC beams. Newly developed pixel detectors, based on commercial high voltage and/or high resistivity full CMOS processes, hold promise as next-generation active pixel sensors for inner and intermediate layers of the upgraded ATLAS tracker. The presentation will summarize recent development and tests on CMOS sensors produced as charge-coupled pixel detectors (“CCPD”) in the AMS 180nm process as well as recent tests of monolithic XFAB SOI sensor test structures. Our development focuses on high granularity and radiation hard pixel sensors, which can be employed as hybrid-pixel detectors as well as monolithic pixel sensors. The sensors also include in pixel signal amplification, shaping, digitisation and position encoding to achieve an optimal spatial resolution for the chosen readout granularity. The use of commercial CMOS processes furthermore allows cost-effective detector construction and simpler hybridisation techniques. The presentation will give an overview of the results obtained on AMS-produced CMOS sensors coupled to the ATLAS Pixel FE-I4 readout chips. The test results include pre-/post-irradiation comparison, measurements of charge collection regions as well as test beam results. The SOI produced sensors by XFAB hold great promise as radiation hard SOI-CMOS sensors due to their combination of partially depleted SOI transistors which reduces back-gate effects, high voltages (up to 200V) and the possibility to use higher resistivity substrates. The presentation will summarise initial radiation measurements up to 700 MRad on transistors and test beam results of pixel sensors.Speaker: Dr Heinz Pernegger (CERN Physics Department)
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First results from the Over-depleted CMOS Monolithic Active Pixel Sensor project (OverMOS)The over-depleted CMOS Monolithic Active Pixel Sensor project (OverMOS) is investigating the use of high-resistivity (rho >~ 1k Ohm cm) substrate layers constructed using the InMAPS process as a way to achieve high-radiation tolerance, low power, and high speed. The InMAPS process allows MAPS pixels to have the same complexity of electronics as found in hybrid sensors without compromising the charge collection performance. No high voltage is used at the front of the design, making this architecture fully compatible with CMOS electronics. A small CMOS-level voltage is enough to create an electric field in the depletion region, thus speeding up charge collection and reducing the spread of charge between several pixels. This also enhances the signal to noise ratio and improves radiation hardness, as the reduced charge collection time means the sensor is less affected by the reduction of the minority carrier collection time due to the lattice damage generated by Non Ionising Energy Loss (NIEL). We report on the first results from test structures implemented In TowerJazz 180nm CMOS and plans for a full architecture prototype.Speaker: Dr Jens Dopke (Rutherford Appleton Laboratory)
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First results of a novel silicon drift detector array designed for low energy X-ray fluorescence spectroscopyWe developed a trapezoidal shaped matrix with 8 cells of Silicon Drift Detectors (SDD) featuring a very low leakage current (below 180 pA/cm^2 at 20 C) and a shallow uniformly implanted p+ entrance window that enables sensitivity of at least up to photons of oxygen K-alpha-1 emission line (524.9 eV). The matrix consists of a completely depleted volume of silicon wafer subdivided into 4 square cells, 39 mm^2 each, and 4 half-size triangular cells. The energy resolution of a single square cell, readout by the ultra-low noise SIRIO charge sensitive preamplifier, is 140 eV FWHM at 5.9 keV and 0 C. The total sensitive area of the matrix is 233 mm^2 and the wafer thickness is 450 µm. The detector was developed in the frame of the INFN R&D project ReDSoX in collaboration with FBK, Trento. Its trapezoidal shape was chosen in order to optimize the detection geometry for the experimental requirements of low energy X-ray fluorescence (LEXRF) spectroscopy, aiming at achieving a large detection angle. We plan to exploit the complete detector at the TwinMic spectro-microscopy beamline at the Elettra synchrotron (Trieste, Italy). The complete system, composed of 4 matrices, covers up to 40% of the isotopic photoemission hemisphere. This geometry provides a 10 times improvement over the present detector configuration. We report on the layout of the SDD matrix and of the experimental set-up, as well as the spectroscopic performance measured at different temperatures and bias conditions.Speaker: Mr Alexandre Rachevski (INFN Trieste)
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Generalization of the One Dimensional Modeling and Design Considerations of Spiral Si Drift Detectors: Flat (Straight) Drift Channels and Constant Drift FieldsThe one-dimensional design consideration for the spiral (cylindrical geometry) Si drift detector (SDD) described in literature [1-2] has been modified and generalized for small drift distance (R) compatible to the detector thickness (d), i.e. for R∼d, and for non uniform backside biasing situations. With smaller R, an array of SDD with small pixel size down to a few hundreds of microns will be possible. Also, by applying a non uniform biasing voltage with a gradient similar (proportional) to the front side, one can increase the reach-through voltage, resulting in a large drift field for carriers. This can be important for large R (> 3mm), or for high resistivity Si substrates (>8 kΩ cm). In the modeling, the one-dimensional solution to solve the electric potential and drift field, as well as the spiral design have been modified and generalized for all cases. With a careful design of electric field profiles on both sides, one can obtain the optimum case of of a spiral SDD with a strait (flat) drift channel and constant drift field throughout the carrier drift channel. The previous solution in the literature is an approximation of this work for R>> d and with a curved drift channel.Speaker: Prof. Zheng Li (Xiangtan University, Xiangtan, China)
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Graphene-based Field Effect Transistors as Radiation SensorsSince its discovery in 2004, Graphene has been proposed in a wide number of applications, including microelectronic devices and photo-detectors, thanks to its unique electronic properties. Here, we propose the implementation of graphene-based field effect transistor (FET) as radiation sensor. Graphene is employed as the gate readout electrode, able to sense any changes in the field distribution induced by ionization in the underneath absorber, because of the strong variation in the graphene conductivity close to the charge neutrality point. This approach could open up the possibility of achieving high-energy resolutions in radiation detection, not through direct absorption of radiation, but rather by sensing energy absorption in an adjacent medium. With the help of T-CAD software, we have simulated a graphene-FET realized on silicon, having one micrometric strip of graphene as a gate electrode on top of silicon dioxide. First results revealed that, by properly choosing the structures parameters, the e-h pairs generated upon visible light illumination are able to drive the electric field on the graphene gate up to values suitable for effective sensing. Once the optimized parameters will be established, we will fabricate and test the first prototypes, by exploiting the graphene synthesis platform recently installed at LNF and the micro-fabrication facilities made available by the two CNR Institutes (IMM and IFN) involved in the project and supporting this research activity.Speaker: Alessandra Di Gaspare (LNF)
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High Voltage Monolithic Active Pixel Sensors for the PANDA Luminosity DetectorThe PANDA-Experiment will be part of the new FAIR facility at Darmstadt, Germany. It is a fixed target experiment in the antiproton storage ring HESR providing beams with excellent resolution $\Delta$p/p\,=\,10$^{-5}$. The scientific scope of PANDA consists of several pillars like: hadron spectroscopy, properties of hadrons in matter, nucleon structure and hypernuclei. In particular with PANDA it will be possible to study QCD bound states consisting of charm quarks and measure their shapes in energy scan measurements with precision better than 50\,keV. For the normalization of the single scan points the precise determination of the luminosity is needed. The luminosity detector will determine the luminosity by measuring the angular distribution of elastically scattered antiprotons very close to the beam axis (3-8\,mrad). To reconstruct the antiproton tracks very precisely four layers of 50\,$\mu$m silicon sensors with smart pixel readout on chip (HV-MAPS) will be placed inside vacuum around the beam pipe. Those sensors are currently under development by the Mu3e-collaboration. This presentation will discuss the status of the HV-MAPS and the electronic read-out chain.Speaker: Dr Florian Feldbauer (Helmholtz-Institut Mainz/ University Mainz)
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High-Voltage CMOS DetectorsHigh-voltage CMOS (HVCMOS) detectors are depleted active pixel detectors implemented in standard commercial CMOS processes. The sensor element is the n-well/p-substrate diode. The sensor electronics are entirely placed inside the n-well which is at the same time used as the charge collection electrode. High voltage is used to deplete the part of the substrate around the n-well. HVCMOS sensors feature fast charge collection by drift and high radiation tolerance. The development of HVCMOS sensors has started as a small R&D project in Heidelberg. Presently there are more than 10 institutes that are developing such type of sensors. High-voltage CMOS sensors will be used in Mu3e experiment and are considered as an option for ATLAS strip and pixel layers and CLIC. Experimental results obtained with small prototypes are encouraging. We measure for instance detection efficiency of more than 99%. The efficiency is only slightly affected by radiation damage. Bumpless signal transmission works reliably, thinned sensors have been produced. In this talk the status of the HVCMOS developments will be presented. New improvements like the use of high resistivity substrates and time walk compensation will be described.Speaker: Prof. Ivan Peric (KIT Karlsruhe Germany)
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Modeling of Radiation Damage Effects in Silicon Detectors at High Fluences HL LHC with Sentaurus TCADIn this work we propose the application of an enhanced radiation damage model based on the introduction of deep level traps / recombination centers suitable for device level numerical simulation of silicon detectors at very high fluences (e.g. 1÷2×10E16 1 MeV equivalent neutrons). The model is based on a past modeling scheme featuring three levels with donor removal and slightly increased introduction rate which was successfully adopted for the optimization of the silicon detectors operating at LHC. The new fluences expected at HL LHC impose new challenges and the extension of the model (valid up to 1×10E15 n/cm2) is not straightforward. New effects have to be taken into account (e.g. avalanche multiplications and deep-level capture cross section dependencies on electric field, temperature and fluences), at the same time keeping the solid physically based approach of the modeling (e.g. by using no fitting parameters). This will preserve the generality of the approach, allowing its application to the optimization of different kind of detectors. We present the comparison between simulation results and experimental data for p-type substrate structures in different operating conditions (temperature and biasing voltages) for fluences up to 2.2×10E16 n/cm2. The good agreement between simulation findings and experimental measurements fosters the application of this modeling scheme to the optimization of the next silicon detectors to be used at HL LHC.Speaker: Daniele Passeri (University and INFN Perugia)
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Pixel telescope for luminosity measurementThe Pixel Luminosity Telescope is a new complement to the CMS detector for the LHC Run II data taking period. It consists of eight 3-layer telescopes based on silicon pixel detectors that are placed around the beam pipe on each side of CMS viewing the interaction point at small angle. A fast 3-fold coincidence of the pixel planes in each telescope will provide a bunch-by-bunch measurement of the luminosity. Particle tracking allows collision products to be distinguished from beam background, provides a self-alignment of the detectors, and provides for continuous in-time monitoring of the efficiency of each telescope plane. The PLT is an independent luminometer, essential to reduce the uncertainty on the delivered luminosity. This will allow to determine production cross sections, and hence couplings, with higher precision and to set more stringent limits on new particle production. An overview of the project and operational experience during LHC running are presented.Speaker: Andreas Kornmayer (CERN)
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Silicon strip tracking detector development and prototyping for the Phase-2 Upgrade of the ATLAS experimentIn about ten years from now, the Phase-2 upgrade of the LHC is planned. This will result in a severe radiation dose and high particle rates for the multipurpose exeperiments because of a foreseen luminosity of ten times higher the LHC design luminosity. Several detector components will have to be upgraded in the experiments. In the ATLAS experiment the current inner detector will be replaced by an all silicon tracking detector aiming for high performance. The talk will present the development and the latest prototyping of the upgrade silicon strip tracking detector. Its layout foresees low mass and modular double-sided structures for the barrel and forward region. Silicon sensors and readout electronics, so-called modules, are planned to be assembled double-sided on larger carbon-core structures. The modularity allows assembly and testing at multiple sites. Many components need to be developped and their prototyping towards full-size components is ongoing. New developments and test results will be presented. Both silicon sensors and latest electronic readout components and assembly procedures will be shown. The talk will also discuss the experience with the prototyping and give an outlook towards final production.Speaker: Dr Susanne Kuehn (Albert-Ludwigs-University Freiburg)
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The ATLAS Diamond Beam MonitorAfter the first three years of the LHC running the ATLAS experiment extracted it's pixel detector system to refurbish and re-position the optical readout drivers and install a new barrel layer of pixels. The experiment has also taken advantage of this access to also install a set of beam monitoring telescopes with pixel sensors, four each in the forward and backward regions. These telescopes were assembled based on chemical vapour deposited (CVD) diamond sensors to survive in this high radiation environment without needing extensive cooling. This talk will describe the lessons learned in construction and commissioning of the ATLAS x Diamond Beam Monitor (DBM). We will show results from the construction quality assurance tests, commissioning performance, including results from cosmic ray running in early 2015 and also expected first results from LHC run 2 collisions.Speaker: Dr Doug Schaefer (CERN)
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Downscaling of detectors on high resistivity semiconductorsElectrical contact properties play a major in the overall performance of metal-semiconductor-metal (M-S-M) type detectors. For near-room-temperature applications the M-S-M detectors have to be constructed with high resistivity, wide bandgap semiconductors, in order to limit the electrical noise related to leakage currents. In wide bandgap semiconductors the high resistivity is often achieved (willingly or unwillingly) through deep-trap compensation process. Introduction of such deep-traps affects not only the resistivity, but also carriers' lifetimes, and thus charge collection efficiency. However, even high resistivity semiconductor with long carrier lifetimes does not guarantee low leakage current, or good detection performance if the contacts are not optimized. The contacts are known to affect the polarization, and leakage currents. Understanding and modeling the effects of contact (detector) downscaling, particularly on high resistivity semiconductors are complex tasks. In this study finite element computation was employed to solve combined Poisson and continuity equations for three-dimensional M-S-M detectors. The effects of contact dimensions, charge carriers' velocity saturation, and contact generation-recombination velocity were investigated.Speaker: Prof. Arie Ruzin (Tel Aviv University)
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Front end, Trigger, DAQ and Data ManagementConveners: Prof. Joao Varela (LIP Lisbon), Dr Stefan Ritt (PSI, Switzerland)
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The WaveDAQ system for the MEG II upgradeThe MEG II experiment at PSI requires a new TDAQ system with stringent demands. About 9000 channels of waveform digitizing in the GHz range must be combined with SiPM biasing, preamplification and flexible triggering in a limited space. The new WaveDAQ system fulfils these requirements by introducing a new compact crate system which combines gigabit serial links in a dual-star topology with picosecond-precision clock distribution and high voltage biasing. An integrate shelf management monitors and controls the whole system including the high voltage part, and allows for remote firmware updates of all boards. The system combines 256 channels in a 3 HE crate including low voltage and high voltage power supplies, premaplification with variable gains, switchable signal shaping, 5 GSPS 12 bit waveform digitizing with the DRS4 Switched Capacitor Array Chip and 100 MHz 14 bit contiunous digitization for trigger purposes. An integrated high precision clock distribution system allow for time measurements with a precision down to a few picoseconds. The paper presents the design principles of the system, followed by test measurements with the prototype boards, and indicates how this flexible system can be used in many other applications in particle physics, gamma ray astronomy and in PET systems.Speaker: Dr Stefan Ritt (PSI, Switzerland)
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Operation of the Full Format DSSC Pixel Readout ASIC for the European XFELThe DSSC (DEPFET Sensor with Signal Compression) collaboration develops a hybrid pixelated X-ray photon detector with high frame rate and immediate amplitude digitization for experiments at the European XFEL. We present measurements with the first full format 14.9x14mm² pixel readout ASIC for the DSSC detector. The DSSC system is able to record megapixel X-ray images with a frame rate of 4.5 MHz. The readout architecture is specially adapted to the burst structure of the XFEL (bursts with 2880 pulses spaced by down to 221 ns at a rate of 10 Hz) by in-pixel digitization and digital hit data storage and data transfer during the burst gaps. The readout ASICs (130nm IBM CMOS technology) contain 64x64 pixels of 229x204µm² size and include per pixel two low noise front-end versions for DEPFET and silicon drift detectors (SDD), a single-slope 8-bit ADC and local SRAM storage. Particular challenges are the required single photon resolution and the high dynamic range of 10^4 photons at 1 keV, requiring a non-linear characteristic. The DEPFET sensor provides signal compression at the sensor level. For the alternative SDD sensor, signal compression is achieved in the ASIC front-end. The building blocks of the readout electronics and experimental results of the full format ASIC characteristics will be presented. Dispersion of ASIC parameters over the full matrix will be discussed and results of coupling ASICs to detector prototypes (DEPFET and SDD) will be shown.Speaker: Jan Soldat (University of Heidelberg)
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The readout of the upgraded ALICE-ITSDuring the second long shutdown of LHC the ALICE experiment will undergo a major upgrade. As part of this program the current Inner Tracking System (ITS) consisting of six layers of silicon detectors (two pixel, two drift and two strips) will be replaced with a new device comprising seven layers of pixel detectors. The increase to 50 kHz of the peak interaction rate of Pb-Pb collisions, which is planned by LHC, will lead to a combined data rate produced by the ITS of up to 300 Gbit/s. As part of this program two families of pixel chips based on the TowerJazz CMOS Imaging Process are under development as candidates for use in the future ITS. One of the designed pixel chips is ALPIDE, which implements priority encoder readout. The other one is MISTRAL-O and utilises a rolling shutter solution. Both can operate in the continuous mode, with ALPIDE also supporting the triggered option and will format the output data stream into the same 8-bit serial protocol. This allowed the R&D process of higher level Readout Unit to concentrate on a single solution applicable to both cases. All of the components of the readout chain have been modelled in a system level simulation that has been used to optimise its topology and various parameters like the size of pixel chip buffers and readout link bandwidths. We will report on the progress of the R&D efforts, test results of hardware components and the overall expected performance of ALICE-ITS readout system.Speaker: Mr Adam Szczepankiewicz (CERN)
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SAMPIC: a 16-channel, 10-GSPS WTDC digitizer chip for picosecond time measurementSAMPIC is a Waveform and Time to Digital Converter (WTDC) 16-channel chip (AMS 0.18-µm CMOS) which directly measures the arrival time of fast analog signals without the need of any external discriminator. Each channel associates a traditional DLL-based TDC providing a raw time based on a counter and a DLL with an ultra-fast 64-cell deep analog memory (bandwidth > 1.5 GHz, sampling rate > 10GS/s) allowing fine extraction of the time as well as charge, pulse width or rise-time. Each channel also integrates a discriminator that can self-trigger independently or participate into a more complex trigger embedded on-chip. External trigger is also available. After triggering, analog data is digitized on-chip by a massively parallel low-power 11-bit Wilkinson ADC running above 1 GHz and only selected data is then moved out. Dead-time is of 1.6 µs for an 11-bit conversion and as low as 200 ns for an 8-bit conversion which already provides an excellent time precision. A set of boards and DAQ system has already been developed to take data with detectors in a real environment. This setup, including a powerful software with an original interactive graphical interface, has permitted the characterization of the chip, and the measurements of its time resolution which is as good as 3 to 4 ps rms after a simple correction, itself based on a very simple calibration (14 ps rms without any correction). This calibration remains very stable with time and can thus be stored on-board.Speaker: Mr Dominique Breton (CNRS / IN2P3 / LAL Orsay)
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The 40 MHz trigger-less DAQ system for the LHCb upgradeThe LHCb experiment will undergo a major upgrade during the second long shutdown (2018 - 2019), aiming to let LHCb collect an order of magnitude more data with respect to run 1 and run 2. The maximum readout rate of 1 MHz is the main bottleneck of the present LHCb trigger. The upgraded detector foresees apart from major detector upgrades, a full readout into the DAQ, running at the LHC bunch crossing frequency, using an entirely software based trigger. A high-throughput PCIe Generation 3 based read-out board has been designed to read out the detector at 40MHz. The readout boards will allow a cost-effective implementation of the DAQ by means of high-speed PC network. The network-based DAQ system reads data fragments, performs the event building, and transport data to the High-Level software trigger at an estimated aggregate rate of ~32 Tbit/s. Possibile technologies candidates for high speed network under study are Infiniband and Gigabit Ethernet. Different architecture for the DAQ can be implemented, such as push, pull and traffic shaping with barrel-shifter. In order the explore and find the best implementation we are performing tests on different platforms and technologies. The event builder evaluator is flexible, to be used on small size test beds and HPC scale facilities, and allows to explore different network protocols. The architecture of DAQ system and up to date performance results will be presented.Speaker: Dr Antonio Falabella (CNAF)
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Coffee Break
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The Upgrade of the ATLAS First Level Calorimeter TriggerThe Level-1 calorimeter trigger (L1Calo) operated successfully during the first data taking phase of the ATLAS experiment at the LHC. Based on the lessons learned, a series of upgrades is planned for L1Calo to face the new challenges posed by the upcoming increases of the LHC beam energy and luminosity. The initial upgrade phase in 2013-15 includes substantial improvements to the analogue and digital signal processing to cope with baseline shifts due to signal pile-up. Additionally a newly introduced system will receive real-time data from both the upgraded L1Calo and L1Muon trigger to perform trigger algorithms based on entire event topologies. During the second upgrade phase in 2018-19 major parts of L1Calo will be rebuilt in order to exploit a tenfold increase in the available calorimeter data granularity compared to that of the current system. In this contribution we present the lessons learned during the first period of LHC data taking. Based on these we discuss the expected performance improvements together with the upgraded hardware and firmware implementations. The status of the prototypes, integration and commissioning efforts are reviewed.Speaker: Shimpei Yamamoto (ICEPP, the University of Tokyo)
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A Time-Multiplexed Track-Trigger for the CMS HL-LHC upgradeA new CMS Tracker is under development for operation at the High Luminosity LHC from 2025. It includes an outer tracker based on ``PT-modules'' of two different types which will construct track stubs using spatially coincident clusters in two closely spaced sensor layers, to reject low transverse momentum track hits and reduce the data volume before data transmission to the Level-1 trigger. The tracker data will be used to reconstruct track segments in dedicated processors before onward transmission to other trigger processors which will combine tracker information with data originating from the calorimeter and muon detectors, to make the final L1 trigger decision. The architecture for processing the tracker data outside the detector is under study, using several alternative approaches. One attractive possibility is to exploit a Time Multiplexed design similar to the one which is currently being implemented in the CMS calorimeter trigger as part of the Phase I trigger upgrade. The current status of some of the crucial component developments needed to construct modules for the new tracker is described, including recent prototype results. The novel Time Multiplexed Trigger concept is explained, the potential benefits for processing future tracker data are described and a feasible design based on currently existing hardware is presented.Speaker: Prof. Geoff Hall (Imperial College London)
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Graphics Processing Units for HEP trigger systemsThe aim of the GAP project is the deployment of Graphic Processing Units (GPU) in real-time applications, ranging from high-energy physics online event selection (trigger) to medical imaging reconstruction. The final goal of the project is to demonstrate that GPUs can have a positive impact in sectors different for rate, bandwidth, and computational intensity. General-purpose computing on GPUs is emerging as a new paradigm in several fields of science, although so far applications have been tailored to the specific strengths of such devices as accelerator in offline computation. With the steady reduction of GPU latencies, and the increase in link and memory throughputs, the use of such devices for real-time applications in high-energy physics data acquisition and trigger systems is becoming ripe. We will discuss the use of online parallel computing on GPU for synchronous low level trigger, focusing on tests performed on CERN NA62 experiment trigger system. The use of GPU in higher trigger system is also considered. In particular we discuss how specific trigger algorithms can be parallelized and thus benefit from the implementation on the GPU architecture, in terms of the increased execution speed and more favourable dependency on the complexity of the analyzed events. Such improvements are particularly relevant for the foreseen LHC luminosity upgrade where highly selective algorithms will be crucial to maintain a sustainable trigger rates with very high pileup. As a study case, we will consider the Atlas experimental environment and propose a GPU implementation for a typical muon selection in a high-level trigger system.Speaker: Gianluca Lamanna (LNF)
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Front end, Trigger, DAQ and Data Management - Poster Session
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Development of the Quality Control System of the Readout Electronics for the Large Size Telescope of the Cherenkov Telescope Array observatoryThe Cherenkov Telescope Array (CTA) is the next generation VHE gamma-ray observatory, which improves the sensitivity by a factor of 10 in the range 100 GeV–10 TeV and an extension to energies well below 100 GeV and above 100 TeV. CTA consists of different types of telescopes, which are called large size telescope (LST), medium size telescope (MST), small size telescope (SST), and Schwarzschild-Couder telescope (SCT), respectively. The prototype of the LST is currently being built and will be installed at the Observatorio Roque de los Muchachos, island of La Palma, Canary islands, Spain. Having to record very fast signals in a noisy environment where the background frequency can reach up to 400 MHz, a fast digitization speed of the readout system coupled to a fast photosensor like a photomultiplier tube (PMT) is crucial to increase the pixel signal-to-noise ratio. Each telescope is equipped with several thousand photon sensor pixels and the readout system attached to the sensors is in a camera container located at the focal position. The readout system for the LST prototype has been designed and around 300 readout boards will be produces in the coming months, half by japanese companies and half by italian companies. We have developed an automated quality control system in order to certify that the board production fulfills specific qualification standards. The system can be used on the company production line in order to identify faulty components and react in short time for fixes to deliver a full set of working board. We will present in detail the design of the quality control system, with special emphasis on the embedded hardware used for producing test pulses of programmable amplitude and the test qualification procedures.Speaker: Riccardo Paoletti (SI)
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The LHCb trigger system and its upgradeThe current LHCb trigger system consists of a hardware level, which reduces the LHC inelastic collision rate of 30 MHz to 1 MHz, at which the entire detector is read out. In a second level, implemented in a farm of 20k parallel-processing CPUs, the event rate is reduced to about 5 kHz. We review the performance of the LHCb trigger system during Run I of the LHC. Special attention is given to the use of multivariate analyses in the High Level Trigger. The major bottleneck for hadronic decays is the hardware trigger. LHCb plans a major upgrade of the detector and DAQ system in the LHC shutdown of 2018, enabling a purely software based trigger to process the full 30 MHz of inelastic collisions delivered by the LHC. We demonstrate that the planned architecture will be able to meet this challenge. We discuss the use of disk space in the trigger farm to buffer events while performing run-by-run detector calibrations, and the way this real time calibration and subsequent full event reconstruction will allow LHCb to deploy offline quality multivariate selections from the earliest stages of the trigger system. We discuss the cost-effectiveness of such a software-based approach with respect to alternatives relying on custom electronics. We discuss the particular importance of multivariate selections in the context of a signal-dominated production environment, and report the expected efficiencies and signal yields per unit luminosity in several key physics benchmarks the LHCb upgrade.Speaker: Mrs Agnieszka Dziurda (Henryk Niewodniczanski Institute of Nuclear Physics PAS)
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ATLAS LUCID electronicsStarting from 2015 LHC will perform a new run, at higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The ATLAS luminosity monitor LUCID has been completely renewed, both on detector design and in the electronics, in order to cope with the new running conditions. The new detector electronics is presented, featuring a new read-out board (LUCROD), for signal acquisition and digitization, PMT-charge integration and single-side luminosity measurements, and the revisited LUMAT board for side A–side C combination. The contribution covers the new boards design, the firmware and software developments, the implementation of luminosity algorithms, the optical communication between boards and the integration into the ATLAS TDAQ systemSpeaker: Federico Lasagni Manghi (BO)
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An FPGA-based trigger for the MEG II experimentFrontier applications both in high energy and medical physics often require to develop custom electronic to be tailored to the specific detection technique being used, so as to accomplish either trigger or data acquisition (DAQ) tasks. For instance, this used to be the case of the first phase of the MEG experiment, where detector signals were split to seperate trigger and digitizer VME modules. For the phase two of the experiment, we decided instead to develop a new, multi-purpose system, conceived to operate both functions on 3U Eurocard boards plugged to a custom backplane with point-to-point connection for data readout and command handshaking. Here we focus on the on-line reconstruction of detector signals and event selection at a trigger level. Basic algorithms are implemented on a Xilinx Spartan6 FPGA, hosted on the same board as the DRS Gigasampler. Detector signals are sampled by a slower digitizer, namely a 100 MHz, 14-bits FADC, to continuously feed the on-board FPGA. Data from different crates, each connected to a set of detector channels, are then gathered by trigger concentrator boards (one per crate) and further processed by higher-level algorithms to issue a trigger, in the case of a candidate signal event, within 450 $\mu$s from event occurrence. We describe the major features of the system and its performances in terms of selection efficiency and background rejection. We also discuss about possible extension of such a system to other applications than particle physics.Speaker: Donato Nicolò (PI)
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VME Rear Transition Module with Backplane Data Access Capability for the ATLAS FTK UpgradeThis paper describes a data processing board (AUX) designed for the ATLAS Fast Tracker (FTK), a system that does global track reconstruction in ~100 µs. The AUX processes silicon detector hits from 8 pixel and silicon strip layers, with typical data rates of 2 Gbps per layer. Each of 128 AUX boards will send hits to its adjacent pattern recognition board and receive back track roads, narrow regions containing track candidates. For each road, all combinations of 1 hit per layer are fit, a chi^2 cut is applied, and then duplicate tracks are removed. On average, 4 track candidates are fit on the board per nanosecond. The board is a VME Rear Transition Module (RTM) with six large FPGAs from the Altera Arria V family. In order to provide for configuration, setup and monitoring of these chips, a special VME data access feature was developed to provide backplane data transfers to and from the RTMs, while being in full compliance with the VME64xP Specifications. It employs the J2 user-defined feed-through pins to connect with the front module, allowing its slave interface to service FPGAs located both in the front and in the rear. As a result, a crate master, sees devices on this rear card as being part of the corresponding front module.Speaker: Mr Mircea Bogdan (The University of Chicago)
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The timing upgrade project of the TOTEM RP detectorsWe describe the upgrade project developed by the TOTEM Collaboration to measure the time of flight (TOF) of the protons in the vertical Roman Pot detectors. The physics program that the upgraded system aims to accomplish will be addressed. Simulation studies allowed to define a geometry of the sensor such that the detection inefficiency due to the pile-up of the particles in the same electrode is low even with a small amount of read-out channels. The measurement of the protons TOF with $\sim$50 ps time resolution requires the development of several challenging technological solutions. The arrival time of the protons will be measured by sCVD diamond detectors, for which a dedicated fast and low-noise electronics for the signal amplification has been designed. Indeed, while diamond sensors have the advantage of higher radiation hardness, lower noise and faster signal than silicon sensors, the amount of charge released in the medium is lower. The sampling of the waveform is performed at a rate up to 10 GS/s with the SAMPIC chip. The sampled waveforms are then analysed offline where optimal algorithms can be implemented to reduce the time walk effects. The clock distribution system, based on the Universal Picosecond Timing System developed at GSI, is optimized in order to have a negligible uncertainty on the TOF measurement. Finally an overview of the control system which will interface the timing detectors to the experiment DAQ is given.Speaker: Dr Mirko Berretti (CERN)
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The supply voltage apparatus of the CUORE experimentThe Electronics system of experiments for the study of rare decay, such as double beta decay, must be very stable over the very long expected runs. We introduce our solution for the power supply of such an experiment, CUORE. The power supply chain consists in this case of a series of ACDC’s, followed by DCDC’s and then linear regulators. We emphasize here our approach to the DCDC regulation system that was designed with a complete rejection of the switching noise, across 50 MHz bandwidth. In the experimental layout the DCDC will be located far from the very front-end, with long connecting cables (10 m). We introduced our very simple and safe solution to prevent huge overvoltages, due to the energy stored in the cable, generated after the release of accidental short circuits, so avoiding destructive effects. Some microcontrollers take care of the DCDC operation and from the control room the managing and monitoring of every DCDC is possible via CAN BUS protocol, coupled via optical fibres. CUORE is an array of 1000 cryogenic detectors that will need 30 of our DCDC’s in its final setup. Production results and statistics will be shown.Speaker: Gianluigi Ezio Pessina (MIB)
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The first level trigger of JEM-EUSO: concept and testsJEM-EUSO is a space mission devoted to the investigation of Ultra-High Energy Cosmic Rays and Neutrinos (E $> 5 \cdot 10^{19}$ eV) from the International Space Station (ISS). The telescope is formed by a system of three Fresnel lenses and a focal surface filled with multi anode photomultipliers read by a front-end electronics based on the single photon counting. The trigger system should face different major challenging points: a) to manage a large number of pixels ($\sim 3 \cdot 10^5$); b) to use a very fast, low power consuming, and radiation hard electronics; c) to achieve a high signal-to-noise performance and flexibility; d) to cope with the limited down-link transmission rate from the ISS to Earth. In this contribution the general overview of the first trigger level for cosmic ray detection is reviewed; tests that validate its performance are discussed.Speaker: Dr Mario Edoardo Bertaina (TO)
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The WaveCatcher Waveform Digitizers: high-end instrumentation for characterization of advanced fast detectorsTThe WaveCatcher digitizers are proposing an alternative to oscilloscopes or ADC-based digitizers. They are based on the SAMLONG Switched Capacitor Array (AMS CMOS 0.35-µm). This circuit permits sampling high speed signals like very short pulses (range of 2.5 V, 12 bits coding, 500 MHz bandwidth, sampling rate between 0.4 and 3.2 GS/s). The sampling depth is of 1024 samples, which fits with most applications where readout dead-time is not critical. The number of channels of the WaveCatcher digitizers ranges from 2 for the USB-powered version to 64 (optionally 72). Sampling time precision is better than 5 ps rms, which permits using the system as a high-resolution TDC between any set of channels, the time precision remaining constant between chips and boards. Moreover, the boards and systems offer a lot of functionalities, like threshold-triggering on any channel and numerous trigger modes including smart coincidences. A firmware block located in each channel permits performing on-board real-time extraction of the main signal characteristics (amplitude, charge, time, …) , and individual rate counters are also implemented. In parallel to hardware and firmware, we developed a powerful and user friendly acquisition software running on PC and transforming the latter into a 2 to 64-channel oscilloscope. It permits saving data files directly on disk, and is currently used in most WaveCatcher system applications. A C-library is also available for Windows or Linux code development.Speaker: Mr Dominique Breton (CNRS / IN2P3 / LAL Orsay)
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The Upgrade for the Data Acquisition System of the KOTO DetectorThe goal of KOTO experiment at J-Parc is to discover and measure the rate of the rare decay . The data acquisition system is built around a 14-bit 125MHz ADC frontend boards and a three-tiered trigger system. The detector analog signals are shaped, digitized and stored inside a 4 μs deep pipeline. The L1 and L2 trigger boards received data from the ADC via 2Gbs. Data passing the L2 decision are sent to a computer cluster via a 1Gb Ethernet connection based on UDP protocol for event reconstruction and L3 trigger. The DAQ system was used during KOTO first physics run in May 2013 and ran at sustained L2 trigger rates of 14KHz, as per design specifications. An upgrade to the L3 architecture using the Infiniband network communication for event building will be commissioned in March 2015. It is complemented by enhancements in the clock distribution system and a redesigned Master Trigger and Control board, which allows to save the data in separate trigger streams. To cope with the increase in proton intensity projected for 2016 and 2017, a major upgrade to the L2 Trigger hardware based on the ATCA standard is being considered. The ATCA standard provides a natural solution to the current KOTO DAQ constraints, including communication between boards and higher input and output bandwidth. This framework will provide for a L2 trigger able to implement real-time clustering and timing analysis of different components.Speaker: Dr Monica Tecchio (University of Michigan)
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The Trigger and Data Acquisition System for the 8 tower subsystem of the KM3NeT detectorKM3NeT is a deep-sea research infrastructure being constructed in the Mediterranean Sea. It will host a large Cherenkov neutrino telescope that will collect photons emitted along the path of the charged particles produced in neutrino interactions in the vicinity of the detector. The philosophy of the DAQ system of the detector foresees that all data are sent to shore after a proper sampling of the photomultiplier signals. No off-shore hardware trigger is implemented and a software selection of the data is performed with an on-line Trigger and Data Acquisition System (TriDAS), to reduce the large throughput due to the environmental light background. A first version of the TriDAS has been developed to operate a prototype detection unit deployed in March 2013 in the abyssal site of Capo Passero (Sicily, Italy), about 3500 m deep. A revised and improved version has been developed to meet the requirements of the final detector, using new tools and modern design solutions. First installation and scalability tests have been performed at the Bologna Common Infrastructure and results comparable to what expected have been observed.Speaker: Mr Matteo Manzali (CNAF, Università degli Studi di Ferrara)
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The RD53 effort towards the development of a 65 nm CMOS pixel readout chip for extreme data rates and radiation levelsThe next generation of silicon pixel detectors for the phase-II upgrade of ATLAS and CMS at the High Luminosity LHC sets unprecedented requirements to the microelectronic readout systems. Front-end integrated circuits must provide advanced analog and digital functions in pixel readout cells with a pitch of a few tens of a um. Operating at low power dissipation, they must handle huge data rates and stand extreme radiation levels. The community of designers is studying the 65nm CMOS technology as a tool to achieve the ambitious goals of these future pixel systems, and has organized itself in the RD53 project to tackle the challenges associated with mixed-signal design in this process. The tolerance of 65nm CMOS to extreme radiation levels is a major subject of RD53, and this paper will review the current status of radiation effects studies. Various solutions are being explored for analog circuits performing signal amplification and analog-to-digital conversion in the pixel readout cells. RD53 is studying a pixel matrix digital readout architecture that handles huge hit rates in a power-efficient way, delivering data off the chip with a large output bandwidth. RD53 has submitted small prototype chips with the goal of testing various options for the analog cells and for their integration in a mostly digital environment. Test results on these chips provide the basis for future submissions of larger prototypes towards the goal of fabricating a full-scale integrated circuit in 2016.Speaker: Valerio Re (PV)
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The Level 0 trigger processor for the NA62 experimentThe NA62 experiment at CERN SPS is devoted to the measurement of the very rare kaon decay K+-> pi+ nu nubar. The expected branching ratio has been recently estimated to be of the order of 10−10, thus requiring a high intensity kaon beam. The high rate of incident particles affects the design of the trigger and data acquisition for the experiment. In particular, the lowest level (L0) trigger represents a crucial component in reducing the event rate, estimated to be about 10 MHz, by a factor 10 with a maximum latency of 1 ms. More recently, the implementation of trigger processors has been based on FPGA devices, gaining great flexibility in maintaining, improving filter algorithms and configuring hardware functionalities by specific programming languages. For the NA62 experiment, two approaches for the realization of L0 trigger processor were developed. A first approach is totally based on the use of a commercial FPGA, while the second one joins a commodity PC to the same tool. In both cases the FPGA device receives data from detectors via Gigabit Ethernet links and routes selected triggers to the local trigger unit of the experiment. In the second approach data are immediately stored, via PCI-express, into the DDR memory of the PC, which performs the event selections. The first approach features fully real-time processing with guaranteed constant latency, but limitations appear in the limited FPGA resources, concerning algorithm implementation and memory depth. On the other hand, in the PC-based trigger processor the implementation of complex algorithms is much simpler and any maintenance operation does not imply to re-configure the FPGA. Anyway, one can lose the full synchronization inside L0 because the PC does not respond as a real-time device.Speaker: Ilaria Neri (FE)
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The GANDALF Framework: Readout and Trigger System for the CAMERA detector at COMPASS IITo measure Deeply Virtual Compton Scattering cross sections the detection of recoil protons is mandatory. Therefore the CAMERA detector was developed for COMPASS II at CERN, consisting of two layers of concentric arranged scintillating slats, surrounding a liquid hydrogen target. The detector design allows for reconstruction of track and energy deposition of recoiled protons, using Time-Of-Flight together with amplitude information from photomultipliers. The signals from 96 channels cover a dynamic range from 0V to -4V, have a rise-time of 3ns and its time information needs to be obtained with a resolution of 200ps to meet the requirements for the track reconstructions. The GANDALF Framework consists of an electronic readout system, based on VXS/VME64x modules, which allow for digitizing the detector signals at 1GS/s at a resolution of 12bit. In real-time, the data is processed by a Virtex-5 FPGA, calculating time and amplitude of the signals. From up to 18 sampling ADC boards, corresponding to 144 ADC channels, this information is streamed to a single central proton trigger unit, the Tiger module. Here a Virtex-6 SXT FPGA calculates geometric pattern and time coincidences of the detector signals. By this step recoil protons are identified in real time [2]. A second TIGER module is used for the distribution of the experiment wide clock beat and the first level trigger signals. The same module collects time stamps, signal amplitudes and integrals, compiles event information and acts as a readout driver module for the data acquisition system. In this talk an overview of the readout and trigger system for the CAMERA detector and the performance of the GANDALF Framework will be explained and results of the 2012 pilot run at COMPASS II will be presentedSpeaker: Mr Florian Herrmann (University of Freiburg)
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The Central Logic Board for the KM3NeT detector: design and productionThe KM3NeT deep sea neutrino observatory will include a very large number of multi-Photomultiplier (PMT) optical modules (DOM) to detect the Cherenkov light generated by secondary particles produced in neutrino interactions. The Central Logic Board (CLB) has been developed to acquire timing and amplitude information from the PMT signals, implementing time-to-digital conversion (TDC) with time over threshold (TOT) technique. All the collected data are transmitted to shore using a wide-bandwidth optical network. All the DOMs are kept synchronized in time within 1 ns precision using the White Rabbit (WR) Precision Time Protocol (PTP). A large Field Programmable Gate Array (FPGA) has been adopted to implement all the specifications witht the requested performances. The CLB will be also used in the base container of the detection unit (DU) to set-up and monitor all the requested functionalities: in this scenario a dedicated firmware and software will be deployed on board. The design has been started in early 2013 and several prototypes have been developed. After deep test carried on in different EU laboratories, the final mass production batch of 600 boards has been ordered and built: all the CLB are now ready for integration in the DOMs and base containers. The first two KM3NeT DU will be deployed in spring-summer 2015 and all other units are in advanced stage of integration.Speaker: Paolo Musico (GE)
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The computing and data infrastructure to interconnect EEE stationsThe Extreme Energy Event (EEE) experiment is devoted to the search of high energy cosmic rays through a network of telescopes installed in around fifty high schools distributed throughout the Italian territory. Such a structure requires a peculiar data management infrastructure to collect data registered in stations very far from each others and to allow a coordinated analysis. Such infrastructure is provided by INFN-CNAF, which operates a Cloud facility, based on the OpenStack opensource Cloud framework, that provide Infrastructure as a Service (IaaS) for its users. In 2014 EEE started to use it for collecting, monitoring and reconstructing the data acquired in all the EEE stations. For file syncing between the stations and the INFN-CNAF infrastructure we used BitTorrent Sync, a free peer-to-peer software designed to optimize data syncronization between distributed nodes. All the data folders are syncronized with the central repository in real time to allow an immediate reconstruction of the data and their publication in a monitoring webpage. We present the architecture and the functionalities of this data management system that provides a flexible environment for the specific needs of the EEE project.Speaker: Francesco Noferini (BO)
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Study of the spatial resolution for binary readout detectorsOften the binary readout is proposed for high granularity detectors to reduce the generated data volume to be readout at the price of a somewhat reduced spatial resolution compared to an analogue readout. In this contribution we show that the detector geometry could be optimized to offer an equivalent spatial resolution than with an analogue readout. In our work we have been studying single hit resolutions obtained with a binary readout using simulations as well as analytical approaches. The resolution has been studied in a generic case, as a function of several parameters: strip pitch, diffusion coefficients, incident track angle, primary electron statistics, etc. Consequently this study can be useful for detector optimization and may bring new ideas of detector developments. The speaker will present three different cases : silicon sensor, Micromegas, and GEM-based detector, and shed light on the principle behind.Speaker: Dr Ryo Yonamine (Université libre de Bruxelles)
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Smart Fast-Digitizer system for astro-particle physics detectorsWe developed a Fast-Digitizer based zero-suppression algorithm which supports single channel self-triggering, TDC and ADC functionalities, and detector triggering capabilities. We implemented and successfully tested the system in the veto of the DarkSide experiment for the search of dark matter, composed by a liquid scintillator detector equipped with 110 PMTs and a water Cherenkov detector equipped with 80 PMTs. The system can be used as it is for any next generation dark matter or neutrino experiments which use photo-detectors and is scalable up to tens of thousands of channels.Speaker: Dr Stefano Davini (GSSI)
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Self-Triggering Readout System for the Neutron Lifetime Experiment PENeLOPEThe aim of PENeLOPE is a high-precision measurement of the neutron lifetime and thereby an increase of the parameter's precision by one order of magnitude. In order to achieve an increasingly higher accuracy, modern experiments naturally require state-of-the-art readout electronics, as well as high-performance data acquisition systems. This talk will therefore present the readout system for the neutron lifetime experiment PENeLOPE, which is currently being designed at the department of physics at Technische Universität München. The system's readout chain involves preamplifier, shaper, sampling ADC, and a data processing stage implemented on field programmable gate arrays (FPGAs). Due to the incorporated signal detection, the system is able to process data from 1,000 self-triggering channels, each of which is hit by 10 particles/sec. The corresponding data rate of 1.5 MB/sec is transferred to the outside of the experiment by a high-speed optical interface, which has been developed to meet the special experimental requirements of PENeLOPE. The main focus of the talk will be set on the performance and tests of the trigger algorithm as well as on characteristics and properties of the optical interface. The project is supported by the Maier-Leibnitz-Laboratorium (Garching), the Deutsche Forschungsgemeinschaft and the Excellence Cluster "Origin and Structure of the Universe".Speaker: Mr Dominic Gaisbauer (Technische Universität München)
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Research and Development for a Free-Running Readout System for the ATLAS LAr Calorimeters at the High Luminosity LHCThe ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}/cm^2/s$. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of $3000~fb^{-1}$. In the HL-LHC phase, the increased radiation levels require a replacement of the front-end electronics of the LAr Calorimeters. Furthermore, the ATLAS trigger system is foreseen to increase the trigger accept rate by a factor 10 to 1 MHz and the trigger latency by a factor of 20 which requires a larger data volume to be buffered. Therefore, the LAr Calorimeter read-out will be exchanged with a new front-end and a high bandwidth back-end system for receiving data from all 186.000 channels at 40 MHz LHC bunch-crossing frequency and for off-detector buffering. The talk will give an overview of the developement of radiation tolerant components like low-noise pre-amplifier and shapers, 10-14 bit and 40-80 MHz analog-to-digital converters (ADCs) with low power and latency, integrated serializer and optical transceivers, as well as a 140 Tb/s digital processing system based on high-performance FPGAs. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented. sented.Speaker: Mr Maximilian Hils (Technische Universität Dresden)
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Real time tracking with a silicon telescope prototype using the “artificial retina” algorithmWe developed a prototype of a silicon tracker with real time tracking capabilities. The working principle is based on the ‘artificial retina’ algorithm, based on extensive parallelisation of data distribution and pattern recognition. The algorithm, inspired by neurobiology, has been implemented on custom data acquisition boards based on FPGAs Xilinx Kintex 7 lx160 in three main logic modules: a switch for the routing of the detector hits, a pool of engines for the digital processing of the hits, and a block for the calculation of the track parameters. The architecture is fully pipelined and allows the reconstruction of real-time tracks with a latency below 100 clock cycles, corresponding to 0.25 microsecond at 400 MHz clock. The silicon telescope consists of 8 layers of single-sided silicon strip detectors with 512 strips each. The detector size is about 10 cm x 10 cm and the strip pitch is 183 um. The detectors are read out by Beetle chips, custom ASICs developed for the LHCb experiment, which provide the measurement of the hit position and pulse height of 128 channels. We report on the first results of the fast tracking device and compare with simulations.Speaker: Mr Marco Petruzzo (Universita' di Milano and INFN Milano)
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Radiation testing campaign results for understanding the suitability of FPGAs in detector electronicsSRAM based Field Programmable Gate Arrays (FPGAs) have been rarely used in High Energy Physics (HEP) due to their sensitivity to radiation. The last generation of commercial FPGAs based on 28 nm feature size and on Silicon On Insulator (SOI) technologies are more tolerant to radiation to the level that their use in front-end electronics is now feasible. FPGAs provide re-programmability, high-speed computation and fast data transmission through the embedded serial transceivers. They could replace expensive custom application specific integrated circuits in front end electronics in locations with moderate radiation field. The use of a FPGA in HEP experiments is only limited by our ability to mitigate single event effects induced by the high energy hadrons present in the radiation field. In this paper, we summarize results of a two-year study of Xilinx 7-series devices on their susceptibility to a HEP experiment radiation field. Experimental results from irradiation campaigns in the USA and Europe on ionizing dose studies up to 300 krad, and single event effects measurements performed with high-energy neutrons up to 1x10exp11 n/cm2 and protons up to 1x10exp13 p/cm2, will be presented. After the proton exposure, the devices tested presented no permanent operational failure except for a 10% increase in the core-logic power consumption, well within the component specification. To mitigate single event upsets we have implemented techniques such as Triple Module Redundancy (TMR) and soft error scrubbing. The effectiveness of these implementations will be presented in detail. The paper also describes the various errors detected in the FPGA Multi Gigabit Transceivers (MGT). The estimated lane error rate suggests that the configurable logic that interfaces with the MGT is the most sensitive part of the FPGA. Proper application of mitigation methods, however, can significantly reduce this sensitivity. Future experiments are planned with improved TMR and scrubbing mitigation.Speaker: Alessandra Camplani (INFN Milano, Italy)
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Performance of pile-up mitigation techniques for jets in pp collisions with the ATLAS detectorThe large rate of multiple simultaneous proton-proton interactions, or pile-up, generated by the Large Hadron Collider in Run I required the development of many new techniques to mitigate the adverse effects of these conditions. This presentation shows the methods employed to correct for the impact of pile-up on jet energy, jet shapes, and even spurious additional jets. Energy correction techniques that incorporate sophisticated estimates of the average pile-up energy density and tracking information are described in detail. Jet-to-vertex association techniques are also presented. We also describe the extension of these techniques to ameliorate the effect of pile-up on jet shapes using both subtraction and grooming procedures. Prospects for pile-up suppression at the HL-LHC will be also discussed.Speaker: Mrs Marianna Testa (LNF)
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PANDA Straw Tube Detectors and ReadoutPANDA is a detector under construction dedicated to studies of production and interaction of particles in the charmonium mass range using antiproton beams in the momentum range 1.5 – 15 GeV/c which will be available at the Facility for Antiproton and Ion Research in Darmstadt. PANDA consists of two spectrometers – the Target Spectrometer based on a superconducting solenoid and a Forward Spectrometer using large dipole magnets and covering the most forward scattering angles (Th<10o). In both spectrometers, the deflection of particles trajectories in the magnetic field is measured using self-supporting straw tube detectors. The expected high count rates reaching up to 1 MHz are one of the main challenges for the straw tubes and associated read out electronics. In the talk, the design of the tracking system and the results of a test of the prototype straw tube tracker equipped with a read out chain will be presented. The latter consist of a newly developed ASIC with amplification, signal shaping, tail cancellation, discriminator stages and digital boards -Time ReadOut Boards- with a TDC implementation based on an FPGA featuring time over threshold measurements and fast GbE optical links for the data transmission.Speaker: Mr Pawel Strzempek (Jagiellonian University)
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Optical Wireless Communication system for particle detectors in High Energy Physics.The particle detectors in high energy physics utilize complex networks of high speed optical fibers for communication. Higher bandwidth will be required for future upgrades and any requirements to route new cables may be difficult due to space limitations. Optical wireless communication (OWC) can provide cable-free high speed data links, which could result in reduced material budget and cheaper installation. A joint collaboration of SSSUP and INFN Pisa is targeting the development of such OWC system and here we present the outcome of an initial study. As reference architecture, the inner tracker of Compact Muon Solenoid (CMS) operating in Large Hadron Collider (LHC) is considered. Similar approaches can also be applied to other particle detectors. We studied the performances of an OWC system based on 1550nm source used as transmitter and PIN diodes used as receiver, working at 10cm distance and operating at 2.5Gb/s and 10Gb/s. In particular, we investigated the tolerance to misalignment for different source beam waist as the system must be self-aligning, because no post alignment operation can be performed. It was observed that reasonable tolerance values from +/-0.25mm to +/-0.8mm can be obtained using beam waist ranging from 0.38mm to 3.5mm respectively. We also performed simulations in order to increase tolerance of the system. With an optimized lens at the receiver it should be possible to obtain tolerances bigger than +/-1mm without having any lens at the transmitter.Speaker: Mr Wajahat Ali (Scuola Superiore Sant'Anna Pisa Italy)
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New electronics of the spectrometric channel for the SND detector electromagnetic calorimeterThe Spherical Neutral Detector (SND)[1] is intended for the study electron-positron annihilation processes operating at VEPP-2000[2] e+e- collider, which is located at Novosibirsk, Russia. The main part of the SND detector is a three-layer electromagnetic calorimeter (EMC). The EMC consists of 1640 counters. Each counter includes NaI(Tl) crystal, vacuum phototriode[3], and charge-sensitive preamplifier. Now the SND team has an aim to study e+e- into neutron-antineutron reaction near threshold. One of the necessary condition for this task is to provide the time resolution of about 1 ns or better[4] (now 5 ns) and save current amplitude resolution. To achieve that, new modules for shaping and digitizing signal were designed, manufactured and tested. New shaping module F12M provides optimal signal shape for best time and amplitude resolution. New FADC module will provide recording and processing of the signal oscillogram for the time-of-flight and amplitude calculation. Special algorithm of the signal processing was developed and tested. Achieved time resolution is about 1 ns, the amplitude resolution is 250 keV. References [1] M.N Achasov et al. Nuc. instr. Meth. A 449, 125 (2000); [2] D.E Berkaev et al. Journal of Experimental and Theoretical Physics 140, N2, 247 (2011); [3] V.V. Anashin et al. Nucl. Instr. and Meth. A 379, 522 (1996) [4] A.A.Botov et al. Nucl. Phys. B, Proc. Suppl.162, 41 (2006)Speaker: Mr Ilya Surin (Budker Institute of Nuclear Physics)
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New electronics for the surface detectors of the Pierre Auger ObservatoryThe Pierre Auger Observatory is currently the worldwide largest installation for the investigation of ultra-high energy cosmic rays. Air showers are detected in a hybrid technique by 27 fluorescence telescopes and 1660 water Cherenkov detectors (WCD) distributed over about 3000 km². The Auger Collaboration has decided to upgrade the electronics of the WCD and complement the surface detector with scintillators (SSD). The objective is to improve the separation between the muonic and the e/m shower component for better mass composition determination during an extended operation period of 8-10 years. The surface detector electronics records data locally and forms coincidence trigger based on the GPS timing. The performance of the detectors is significantly improved with a higher sampling rate, an increased dynamic range, new generation of GPS receivers, and FPGA integrated CPU power. The number of analog channels will be increased to integrate the new SSD, but the power consumption needs to stay below 10 W to be able to use the existing photovoltaic system. In this paper, the concept of the additional SSD is presented with a focus on the design and performance of the new surface detector electronics.Speaker: Dr Matthias Kleifges (Karlsruher Institut für Technologie (KIT) - IPE)
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Method of Signal Detection from Silicon Photomultipliers Using Fully Differential Charge to Time Converter and Fast ShaperThe paper presents an implementation of fully differential readout method for Silicon Photomultipliers (SiPM). Front-end electronics consists of fast and slow path. The former creates the trigger signal while the latter produces a pulse width proportional to the input charge. One of the advantages of the circuit is its speed. The fast shaper generates unipolar pulse and utilizes the pole-zero cancelation circuit. The peaking time for single photoelectron is equal to 4.3ns and the FWHM is 6.4ns. The pulse width of the charge to time converter (QTC) depends on the number of photons entering the SiPM at the moment of measurement. The QTC response is nonlinear but it allows to work with signals in wide dynamic range. The pulse width for one photoelectron is equal to 10ns and can be modified. The proposed readout method is effective in measurements of random signals where frequent events tend to pile-up. The QTC provides the information on the total number of photons reaching SiPM during the integration time while the fast shaper generates a pulse each time a group of photons hit the detector. Thermal generation and afterpulses have a strong influence on the width of pulses from QTC. The proposed method enables to distinguish those overlapping signals and get the reliable information on the number of detected photons.Speaker: Mr Mateusz Baszczyk (AGH University of Science and Technology)
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L1Track: a fast Level 1 track trigger for the ATLAS High Luminosity UpgradeWith the planned high-luminosity upgrade of the LHC, the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC design. Due to this the pile-up collisions will increase by a similar factor. The earliest hardware based ATLAS trigger stage ("Level 1") will have to provide an higher rejection factor in a more difficult environment. The Level 1 trigger architecture needs therefore to be improved. A new Level 1 trigger architecture is under study, which, in addition of the “regions of interest” identified by the calorimetry and the muon chambers, also includes the possibility of extracting tracking information and use it for the decision taking process. The expected trigger rates at HL-LHC and the available latency are the key ingredients that will drive the new design. A low-latency and accurate tracking trigger system is being developed in the context of this additional trigger refinement. The design results in a substantial modification of the ATLAS silicon detector readout philosophy: a precursor of the potential merging of detector and trigger architectures in the future silicon detectors at particle colliders. In this context, we will discuss and review the design alternatives and potential approaches that are being actively considered to fulfill such demanding constraints and deliver tracks of quality sufficient to maintain trigger rejection power with a very limited time budget.Speaker: Dr alessandro cerri (LBNL)
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In-pixel conversion with a 10 bit SAR ADC for next generation X-ray FELsThis work presents the design of an interleaved SAR ADC, part of the readout channel of an X-ray imager for application at the next generation free electron laser facilities. The front-end channel, designed in a 65 nm CMOS technology in the framework of the PixFEL project, has to be capable of processing signals in a very large dynamic range (1 to 10000 photons) with single photon resolution at small number of photons. Each channel is equipped with an ADC. This makes the system more robust as compared to the case of conversion at the chip periphery or off chip transmission of analog samples. The choice of the SAR architecture is justified by the need for a good tradeoff between power dissipation, area occupation and conversion speed. While an 8-bit ADC may ensure single photon resolution at small energies and Poisson limited performance for signals towards the high energy range, a 10-bit resolution may be exploited to improve robustness against parameter dispersion and noise. After schematic simulation at the maximum sample rate of 5 MHz, a maximum DNL = 0.125 LSB and a maximum INL = 0.138 LSB were obtained. None of them exceeds 0.5 LSB after post layout simulations. The SNR is 56.6 dB, implying an ENOB = 9.6. The power consumption is 85 uW. The layouts designed for different test chip occupy an area that spans from (97 x 74) um to (97 x 58) um, compatible with the target pitch of the pixel of 100 um. Experimental data are expected for the time of the conference.Speaker: Luca Lodola (PV)
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Front-end chip for Silicon Photo-Multipliers detector with pico-second Time-of-Flight informationA mix-mode readout application specific integrated circuit (STIC3) has been developed for high precision timing measurements with Silicon Photomultipliers (SiPM) for medical imaging and particle physics applications. The STiC3 is 64-channel chip, with fully differential analog front-end for crosstalk and electronic noise immunity. The time and charge information from the SiPM signals are encrypted into two time stamps generated by the integrated Time to Digital Converter (TDC) modules with a resolution of less than 20 ps. The TDC data is stored in an internal memory and transfered to pc over a 160 MBit/s serial link using an 8/10 bit encoding. The chip provides a input bias tuning in a range of 0- 700mV to compensate the breakdown voltage variation of individual SiPMs. Measurements of the analog front-end show a time jitter less than 20 ps and jitter of the TDC together with the digital part is around 37 ps. A Coincidence Time Resolution (CTR) of 215 ps FWHM has been obtained with 3.1 x 3.1x 15 mm2 LYSO:Ce scintillator crystals and Hamamatsu SiPM matric (S12643-050CN(x)). Characterization measurements with the chip and its performances will be presented.Speaker: Mrs Vera Stankova (Detector development)
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Electronics Design and Layout Complexity of the ATLAS New Small WheelsThe LHC resumes its operation in 2015 aiming to deliver an average luminosity of 1×10^34 cm^−2 s^−1. Further upgrades of the experiments and the accelerator in 2018/19 and 2022/23 will allow to further increase the luminosity to 2×10^34 cm^−2s^−1 and 5×10^34 cm^−2s^−1, respectively. For the ultimate HL-LHC phase the expected mean number of interactions per bunch crossing will increase from 55 at 2×10^34 cm^−2s^−1 to ∼140 at 5×10^34 cm^−2s^−1. This increase, drastically impacts the ATLAS trigger rates. For the ATLAS Muon Spectrometer, a replacement of the innermost endcap stations, the so called “Small Wheels”, is therefore planned for 2018/19 to be able to maintain a low pT threshold for single muon and excellent tracking capability also in the HL-LHC regime. The New Small Wheels will feature two new detector technologies, Resistive Micromegas and small strip Thin Gap Chambers conforming a system of ~2.4 million readout channels. Both detector technologies will provide trigger and tracking primitives to the muon trigger system and are already designed as fully compliant with the post-2024 HL-LHC operation. The electronics design of such a system will be implemented including the design of 4 custom front-end ASICs capable to drive trigger and tracking primitives. Among them the 64 channels VMM, a common frontend ASIC providing amplitude, timing measurements, per channel analog-to-digital conversions and in parallel direct trigger outputs. The design integrates the Gigabit transceiver and Slow Control ASICs developed at CERN. The data flow is designed through a high-throughput network. The overall design along with the first ASIC and board prototypes will be presented.Speaker: Dr Sahal Yacoob (University of KwaZulu-Natal)
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EUSO-BALLOON: readout electronics performancesThe EUSO-Balloon experiment is a pathfinder for the satellite mission JEM-EUSO whose goal will be to observe Extensive Air Showers. The experiment consists in launching a balloon, equipped with a set of lenses which is used to focus the fluorescent UV photons on the Photo Detector Module (PDM) which will be controlled by the Data Processing systems. The PDM contains two elements: the 9 Elementary Cell units (EC unit) and the 6 EC-ASIC boards. The EC unit includes four 64-channel MAPMT and a set of PCBs used to supply high voltages to the MAPMTs and to read out the output signals. These signals are transmitted to the front-end electronics, the EC-ASIC boards each of which contains 6 SPACIROC. The ASIC is designed to perform single photon counting in a dynamic range of 1 photoelectron (PE) to 300 PEs/pixel/2.5 µs, with double pulse resolution of 30 ns, and low power consumption (<1 mW/ch). During the year 2013 and 2014, the flight model EC_units and EC_ASIC PCBs were produced and the performance was successfully tested and confirmed. The 24th of August 2014, the EUSO-BALLOON instrument went for a night flight for several hours, 40 km above Timmins (Canada) balloon launching site. The flight has been interesting from the scientific point of view, since different types of grounds could be overflown, as well as regions with and without clouds of different types. This paper will present in detail the performances of the electronics before, during and after the flight.Speaker: Mrs Sylvie Blin (OMEGA/IN2P3/CNRS)
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Digital signal processing for thermal neutron detectors using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMsThis work presents the development of a digital signal processing system for a thermal neutron detector designed for a strain-scanning diffractometer [1]. The detector is based on ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. The main challenges concerning the signal processing are the suppression of the detector background counts due to the SiPM dark count rate and the suppression of the multiple triggers due to the scintillator afterglow, together with a high trigger efficiency and a high neutron rate capability. The output of the SiPM is digitized so that each single photoelectron signal produces a 5ns wide NIM logical pulse. This digitization allows to get rid of the SiPM crosstalk since a simultaneous firing of several SiPM cells always leads to a single logical pulse. The impact of this digitization on the reduction of the background rate of the detector will be presented. The digital signal processing system continuously counts the number of digital pulses during each FPGA clock cycle, i.e., it performs a sampling of the density of digital pulses in time. In this work, several digital filters are investigated and for each filter, the following detector characteristics are evaluated: background rate, trigger efficiency, probability of multiple triggers, neutron rate capability and time resolution. [1] J.-B. Mosset et al., Nucl. Instr. and Meth. A, 764, 299 (2014).Speaker: Dr Jean-Baptiste Mosset (Paul Scherrer Institute)
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Development of the FoCal-E PAD detector and its electronics for the LHC-ALICE experimentIn order to understand the initial state of the high-energy heavy-ion collision, it is proposed to install a forward calorimeter (FoCal) in the LHC-ALICE experiment. FoCal consists of two detectors that are an electro-magnetic calorimeter (FoCal-E) to measure the direct photons and a hadron calorimeter (FoCal-H) to observe the jets. And, FoCal-E has the low-granularity silicon-pad (PAD) modules and the high-granularity silicon-pixel (MAPS) modules. Each PAD module has four pairs of a tungsten tile and the 8 x 8 silicon photodiode array, and the output signal is derived as the current sum of four photodiode cells in the same position. The first beam test of FoCal-E was carried out at the CERN PS and SPS beam lines in 2014, and we developed the trigger signal converting circuit, the temperature monitor, the independent regulated power circuit and the isolated high-voltage generator for PAD modules. The trigger signal converting circuit is used for merging the PAD data with the MAPS data because they are working on different readout systems. The temperature monitor is connected with high-precision digital thermo-sensors through the 1-wired serial interface and it is easy to increase the number of thermo-sensors up to 160. The independent regulated power circuit and the isolated high-voltage generator had a great success to decrease the electric noise on PAD modules. For the next beam test in 2015, we are going on with the new readout system for PAD modules.Speaker: Dr MOTOI INABA (TSUKUBA UNIVERSITY OF TECHNOLOGY)
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Design and test of clock distribution circuits for the Macro Pixel ASICThe innermost part of the CMS outer tracker at the HL-LHC is based on a combination of pixelated and short strip sensors, the so-called Pixel-Strip module (PS). The pixelated layer is read out by means of the Macro Pixel ASIC (MPA), bump bonded to the sensor, as normally done in hybrid pixels. The MPA consists of a matrix of 16x120, 1500um x 100um pixels, and will be designed in a 65 nm CMOS technology. Clock distribution circuits account for a significant fraction of the power dissipation in the readout chip, mainly related to the dynamic power needed to drive the long lines running the clock signal through the wide area matrix. Moreover, the clock signal must be distributed all over the chip with minimum possible skew. A test chip including the clock distribution circuits of the MPA has been fabricated and tested. The prototype chip includes metal structures emulating the long clock lines that will be laid out in the final design of the MPA, and two versions of the drivers and the receivers suitable for operation in the readout chip. These versions are based on CMOS drivers supplied with a reduced supply voltage and on static reduced-swing drivers. Experimental results show that a power saving up to 60% can be obtained with a 0.8V chip supply voltage. The paper will present a summary of the experimental results relevant to the prototype chip, focusing particularly on the power and speed performance and will compare such results with those coming from circuit simulations.Speaker: Luigi Gaioni (University of Bergamo)
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Design and performance of the upgrade of the CMS L1 muon triggerAfter the Long Shutdown 1 LHC will run at a center of mass energy of 13TeV, providing CMS with proton collisions at an expected rate which is almost double the LHC design goal of 10^34 cm-2s-1, and almost three times the peak luminosity reached during Run1 of 7.7 10^33 cm-2s-1. The higher luminosity and center of mass energy of LHC will raise the Level 1 (L1) muon trigger rate by almost a factor six for a given muon pt threshold. It is therefore necessary to increase the muon transverse momentum threshold to keep the trigger rate under 100 kHz, maximum sustainable rate for the CMS detectors. An increase of the L1 trigger thresholds implies a lowering of the efficiency in detecting signals from new physics and consequently a delay in possible discoveries. The CMS muon trigger will be completely upgraded using custom designed AMC boards, with more powerful FPGAs and larger memories. The upgraded CMS trigger muon system will implement pattern recognition and MVA (Boosted Decision Tree) regression techniques in the trigger boards for muon pt assignment, drastically reducing the trigger rate and improving the trigger efficiency. The upgraded system design will exploit the redundancy of the CMS muon detectors at a very early stage merging different muon detector information already at L1. The pileup subtracted information from the upgraded calorimeter trigger will allow to require isolated muons already at L1. The upgrade trigger is also designed to include inputs from GEM, the phase 2 muon detector upgrade, in particular in the very high rapidity region. In this presentation the upgraded CMS L1 muon trigger is described and its expected performance presented.Speaker: Dr Pierluigi Bortignon (University of Florida)
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Characterization of Bandgap Reference Circuits designed for High Energy Physics ApplicationsBandgap reference circuits (BGR) in a commercial 65nm CMOS technology were designed and fabricated in view of potential use in high-energy physics (HEP) applications. Since in bandgaps the dominant radiation-susceptibility is due to the bipolar devices or diodes, a few different versions employing MOSFETs with standard and special layout techniques have been designed. Trimming techniques to adjust the reference voltage as a function of temperature and irradiation are not included in the circuits. Measurement results show a temperature variation as low as ±3.4 mV over a temperature range of 170°C (-30°C to 140°C) and a line regulation at room temperature of 7.6%/V. Measured Vref is 690 mV ±15 mV (3σ) for 26 samples on the same wafer. Circuits correctly operate with supply voltages in the range from 1.32 V down to 0.78 V. A reference voltage shift of only 4.1 mV (around 0.6%) was measured after irradiation with 10 keV X-rays up to an integrated dose of 90 Mrad (SiO2). Irradiation to higher integrated doses and with different sources are already planned. This work discusses the measurements results and their relation with the particular semiconductor device (BJT, diode, MOSFET) employed in the design of the bandgap.Speaker: Francesco De Canio (PV)
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CITIROC 32channel ASIC for SiPM readoutCITIROC is a 32-channel front-end ASIC designed to readout Silicon Photo-Multipliers (SiPM) for the proposed ASTRI SST-2M Small Size Telescopes of the Cherenkov Telescope Array (CTA). CITIROC is an evolution of EASIROC/SPIROC, chip proposed by INAF/Palermo to readout efficiently and at low power the focal plane made of SiPMs. Based on variable gain/low noise preamplifiers and high speed discriminators, it allows easy triggering down to 1/3 of photoelectron (50fC) and provides the 32 discriminator outputs to extract timing down to 50 ps. A second set of 32 discriminators also allows fast event validation with a higher threshold. Each channel is also equipped with a variable bandpass shaper (12.5 ns to 87.5 ns) and peak-sensing holder to provide a multiplexed charge readout up to 2500 pe.(400 pC). As for previous chips, a channel-wise 5V 8-bit DAC allows individual adjustment of the SiPM overvoltage. The power consumption is around 2.5mW/channel allowing two naked chips (64 channels) to be mounted on a small size board. 37 boards equipped with CITIROCs has been realized by INAF/Palermo and successfully tested. In this paper we give a description of the main features of CITIROC.Speaker: Dr Christophe de LA TAILLE (OMEGA CNRS/IN2P3 Ecole Polytechnique)
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An artificial retina processor for track reconstruction at the full LHC crossing rateThe INFN-RETINA is an R&D project aimed at developing and implementing a parallel computational methodology allowing the reconstruction of events with hundred of charged-particle tracks in pixel and silicon strip detectors at 40 MHz, thus suitable for processing LHC events at the full crossing frequency. For this purpose we design and test a massively parallel pattern-recognition algorithm, inspired by studies of the processing of visual images by the brain as it happens in nature. We find that high-quality tracking in large detectors is possible with sub-microseconds latencies when this algorithm is implemented in modern, high-speed, high-bandwidth FPGA devices. This opens a possibility of making track reconstruction happen transparently as part of the detector readout. The detailed geometry and charged-particle activity of a large already-built tracking detector are simulated and used to assess the performance of an artificial retina processor prototype at the current available silicon readout frequency of 1MHz. TEL62 boards, equipped with 4 Altera Stratix III FPGAs providing the adequate computing power, are used for the processing stage of the prototype. We report on the first results of such fast tracking device based on test with simulated and real LHC events.Speaker: Riccardo Cenci (Scuola Normale Superiore and INFN-Pisa)
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ALDO: a radiation-tolerant, low-noise, adjustable low dropout linear regulator in 0.35 micron CMOS technologyIn the current work we present ALDO, an adjustable low dropout linear regulator designed in AMS $0.35\ \mu m$ CMOS technology. It is specifically tailored for the use in the upgraded LHCb RICH detector in order to improve the power supply noise filtering for the front end readout chip (CLARO). ALDO is designed with radiation-tolerant solutions such as an all-MOS band gap voltage reference and other layout techniques that make it able to operate successfully in harsh environments like High Energy Physics accelerators. It is capable of sourcing up to $200\ mA$ while keeping a power supply rejection ratio of at least $40\ dB$ in a very wide frequency range from $10\ Hz$ up to $100\ MHz$. This property allow to suppress the high frequency spikes generated by the DC-DC regulator that is responsible of the first stage of the supply voltage conversion in the upgraded LHCb RICH front end. ALDO also demonstrated a very low noise of $50\ \mu V$ RMS in the same frequency range. Its output is protected with over-current and short detection circuits for a safe integration in tight packaged environments. Design solutions and measurements of the first prototypes are presented in this work.Speaker: Paolo Carniti (MIB)
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A simulation tool for a Silicon Photomultiplier coupled to a scintillating fiberA Monte Carlo simulation, based on Geant 4, for scintillating fibers coupled to a silicon photomultipliers (SiPMs) has been implemented. The software includes the simulation of the SiPM response, taking into account the dark current, the after-pulse and the optical crosstalk effect. The software allows to study the propagation of photons through the fiber, the occupancy of the pixels on the SiPM active area and to obtain the expected distribution of the detected photoelectrons. In this poster we show the different steps of the simulation, from the geometry definition to the response of the SiPM. Finally we show the comparison with data concerning the detection of minimum ionizing and highly ionizing particles, performed with a detector based on thin scintillating fibers coupled to SiPMs.Speaker: Dr EMANUELE RIPICCINI (INFN Roma)
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A proposed DT-seeded muon track trigger for the CMS experiment at the HL-LHCThe LHC program at 13 and 14 TeV, after the observation of the candidate SM Higgs boson, will clarify future subjects of study and shape the tools needed to carry them on. Any upgrade of the LHC experiments for unprecedented luminosities, such as the HL-LHC ones, must then maintain the acceptance on electroweak processes for a detailed study of the properties of the new particle. In particular, key triggers must allow for an acceptance of low-mass scale processes comparable to the one featured in 2012. In such a scenario, a new approach to early trigger implementation is needed. One of the next major steps is the exploitation of high-granularity tracking sub-detectors, such as the CMS Silicon Tracker, in the early trigger decision. This can be crucial for the confirmation of triggers in other subsystems, and for the improvement of the on-line momentum measurement resolution. A muon track-trigger for the CMS experiment at the HL-LHC is presented. A back-extrapolation of DT trigger primitives is proposed to match tracks found at Level 1 with muon candidates. Given the better momentum resolution of the CMS silicon tracker, the crucial role of the muon trigger will be to provide good spatial information to enhance the association with Level 1 tracks. The main figures-of-merit are presented, featuring sharp thresholds and less contamination from lower momentum muons, and an expected rate reduction of a factor 5 to 10 at typical thresholds with respect to the current algorithm.Speaker: Nicola Pozzobon (PD)
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A new highly selective first level ATLAS muon trigger with MDT chamber data for HL-LHCHighly selective first level triggers are essential for the physics programme of the ATLAS experiment at the HL-LHC where the instantaneous luminosity will exceed the LHC Run 1 instantaneous luminosity by almost an order of magnitude. The ATLAS first level muon trigger rate is dominated by low momentum muons, selected due to the moderate momentum resolution of the resistive plate and thin gap trigger chambers. This limitation can be overcome by including the data of the precision muon drift tube chambers in the first level trigger decision. This requires the implementation of a fast MDT read-out chain and a fast MDT track reconstruction. A demonstrator of the fast read-out chain was successfully tested under HL-LHC operating conditions at CERN's Gamma Irradiation Facility. The test results showed that the data provided by the demonstrator can be processed with a fast track reconstruction algorithm on an ARM CPU within the 6~$\mu$s latency of the first level ATLAS trigger anticipated for the HL-LHC. The algorithm was also applied to ATLAS LHC run I data to prove under realistic operating conditions that first level single muon trigger rates as small as the high level trigger rates can be achieved with the new MDT based muon trigger.Speaker: Dr Hubert Kroha (Max-Planck-Institut fuer Physik)
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A high performance Front End Electronics for Drift Chamber readout in MEG experiment upgradeThe new positron tracker for the spectrometer of the MEG experiment at Paul Sherrer Institut (Zurich), based on a high resolution drift chamber, produces typical time separation between consecutive ionization acts in helium-based gas mixture of few nanoseconds. Therefore the electronic readout interface has to be able to process such high speed signals. In order to reach this goal we propose a high performance eight-channels front end electronics which amplifies weak signals from MEG drift chamber tracker. The front end board is designed and tested at INFN of Lecce electronics laboratory and it is based on commercial devices. Each front end channel is a multistage amplifier: the first gain stage is performed by an ADA4927 from Analog Devices: a low noise, ultralow distortion, high speed, current feedback differential amplifier; a THS4509 from Texas Instruments is used as wideband signal output driver. Dedicated networks guarantees protection, matching and decoupling from high voltage wires supply. Careful consideration of design rules preserves signal integrity by minimizing crosstalk between channels. In order to compensate the attenuation introduced by the output cable a double stage of pre-emphasis is implemented to produces a high frequency peak in frequency response. Simulation performed by Spice shows a 3dB bandwidth around 1GHz and a voltage gain of the order of 10. Preliminary measurements show a good agreement with simulation.Speaker: Aurora Pepino (LE)
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A charge amplifier for VUV photomultiplier operating in cryogenic environment.We present the design and the performance of a preamplifier operating in a cryogenic environment, potentially interesting for noble liquid detectors. The circuit design has been constrained by requirements of low power consumption (2mA), low noise (250 microV) and use of commercial components. The gain is 10 with a bandwidth of 100 MHz. The optimal configuration has been obtained by using a cascade of two AD8011 Op-Amps. The amplifier has been integrated onto a PCB with a voltage divider, customised for cryogenic temperature, and coupled to an Hamamatsu R11410 photomultiplier tube. The system has been tested simulating operations in liquid xenon by using VUV light pulses in a controlled bath of liquid nitrogen to keep the temperature close to -100 °C. Performance and further improvements are presented.Speaker: Dr ADRIANO DI GIOVANNI (NEW YORK UNIVERSITY ABU DHABI)
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A New Front-end ASIC for GEM detectors with Time and Charge Measurement CapabilitiesGEM detectors offer interesting solutions for particle detection in several application fields, thanks to their excellent features in terms of spatial resolution, gain, flexibility and cost. In the framework of the project AMIDERHA, which aims at building a new hadrontherapy facility, GEM is the detector of choice for beam monitoring and the associated front-end electronics must be able to provide measurements of the charge delivered by the detector, in order to improve the spatial resolution of the detection system by exploiting charge centroid algorithms. For this purpose, a 32 channel front-end ASIC has been designed in a standard 0.35um CMOS technology. The analog channel is based on the classic CSA+shaper architecture, followed by a peak detector (PD) which works as an analog memory during the read-out phase. A multiplexer routes the outputs of the PDs towards an integrated 8-bit subranging ADC. A trigger signal is generated by fast-ORing the outputs of 32 voltage discriminators which compare the shaper outputs with a programmable threshold. The digital part of the ASIC manages the read-out of the channels, the A/D conversion and the configuration of the programmable features of the chip, via SPI interface. A 100Mbit/s LVDS serial link is used for data communication. The sensitivity of the analog channel is 15mV/fC and the dynamic range is 80fC, with a linearity error less than 1%. The ENC is about 650e- for a detector capacitance of 10pF.Speaker: Mr Fabio Ciciriello (Politecnico Bari, INFN)
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A Fast hardware Tracker for the ATLAS Trigger systemThe trigger system at the ATLAS experiment is designed to lower the event rate occurring from the nominal bunch crossing at 40 MHz to about 1 kHz for a designed LHC luminosity of 10$^{34}$ cm$^{-2}$ s$^{-1}$. To achieve high background rejection while maintaining good efficiency for interesting physics signals, sophisticated algorithms are needed which require extensive use of tracking information. The Fast Tracker (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to perform track-finding at 100 kHz and based on a mixture of advanced technologies. Modern, powerful Field Programmable Gate Arrays form an important part of the system architecture, and the combinatorial problem of pattern recognition is solved by ~8000 standard-cell ASICs named Associative Memories. FTK provides track reconstruction based on the full silicon detector with quasi-offline resolution in approximately 100 $\mu$s/event. The availability of the tracking and subsequent vertex information within a short latency ensures robust selections and allows improved trigger performance for the most difficult signatures, such as $b$-jets and $\tau$s. We present the architecture of the FTK system, the results from integration tests of a slice of the FTK at CERN and discuss the expected physics performance in the harsh environment of high pile-up and high luminosities expected for LHC run IISpeaker: Mr Carlo Pandini (LPNHE Paris)
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A 12-bit SAR ADC integrated on a multichannel Silicon Drift Detector Readout ICA 12-bit analog-to-digital converter (ADC) addressed to Silicon-Drift Detectors (SDDs) multichannel readout front-ends for X and gamma-ray applications is presented. Aiming at digitizing output multiplexed data from the upstream analog filters banks, the converter must ensure at least 11-bit accuracy and a sampling frequency of about 5 MS/s. The ADC architecture is the charge-redistribution (CR) successive-approximation register (SAR). A fully-differential topology has also been chosen for better rejection of common-mode noise and disturbances. The internal DAC is made of binary-scaled capacitors, whose bottom plates are switched by the SAR logic to perform the binary search of the analog input value by means of the monotonic switching scheme. The A/D converter is integrated on SFERA, a multichannel ASIC fabricated in a standard CMOS 0.35 um 3.3 V technology and it occupies an area of 0.44 mm2. Simulated static performance show monotonicity over the whole input-output characteristic while differential (DNL) and integral nonlinearity (INL) appear to be lower than half LSB. Dynamic performance are instead expected to be higher than those of the first ADC prototype, which consisted in 68 dB SFDR, 66.5 dB SiNAD and an effective number of bits (ENOB) equal to 10.75 at full-scale and 4 MS/s sampling rate. The description of the circuit topology and of inner blocks architectures together with the experimental characterization of both static and dynamic parameters is here presented.Speaker: Filippo Schembari (Politecnico di Milano & INFN sez. Milano)
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A New ATLAS Muon CSC Readout System with System on Chip Technology on ATCA PlatformThe ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf through software waveform feature extraction to output 32 S-links. The full system was installed in Sep/2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning towards LHC Run 2.Speaker: Richard Claus (SLAC)
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A Pattern Recognition Mezzanine based on Associative Memory and FPGA technology for Level 1 Track Triggers for the HL-LHC upgrade.The increase of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments to maintain an acceptable trigger rate to select interesting events despite the one order of magnitude increase in the minimum bias interactions. To extract in the required latency the track information a dedicated hardware has to be used. We present the tests of a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC ATLAS and CMS experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.Speaker: Giacomo Fedi (PI)
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A Track Finding Algorithm for a Time Multiplexed L1 Track Trigger for the phase II CMS experimentAt the HL-LHC, proton bunches will cross each other every 25 ns, producing an average of 140 pp-collisions per bunch crossing. To operate in such an environment, the CMS experiment will need a L1 hardware trigger, able to identify interesting events within a latency of 12.5 μs. The future L1 trigger will thus make use also of data coming from the silicon tracker to constrain the trigger rate. The architecture that will be used in future to process tracker data is still under discussion. One interesting proposal makes use of the Time Multiplexed trigger concept, already implemented in the CMS calorimeter trigger for the Phase I trigger upgrade. The proposed track finding algorithm is based on the Hough Transform method. The algorithm has been tested using a simulated pp collision data. Results show a very good tracking efficiency. The algorithm will be demonstrated in hardware in the coming months, using the “MP7”, which is uTCA board with a powerful FPGA capable of handling data rates approaching 1 Tb/s.Speaker: Mr Davide Cieri (RAL)
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Detector Techniques for Cosmology, Astroparticle and General PhysicsConveners: Aldo Morselli (ROMA2), Dr Cristiano Galbiati (LNGS)
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FLARES: a flexible scintillation light apparatus for rare event searchesCompelling experimental evidences of neutrino oscillations and their implication that neutrinos are massive particles have given neutrinoless double beta decay (\bbzn) a central role in astroparticle physics. In fact, the discovery of this elusive decay, besides giving precious information concerning the absolute neutrino mass scale, would unambiguously demonstrate that neutrino and antineutrino are the same particle and that the lepton number is not conserved. On the other hand, all current experimental programs to search for \bbzn\ are facing with the technical and financial challenge of increasing the experimental mass while maintaining incredibly low levels of spurious background. The technique proposed here is the combination in a single device of all the demanding features needed by an ideal experiment: energy resolution, low cost mass scalability, isotope choice flexibility and many powerful handles to make the background negligible. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120\,K. This would provide scintillation detectors with 1\% level energy resolution and a $\mu$s time resolution. The performances of a first production of matrices of Silicon Drift Detectors as well as first measurements of the low temperature light yield of a selection of high purity scintillation crystals will be presented and discussed.Speaker: Monica Sisti (MIB)
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The XENON1T ExperimentThe XENON1T experiment, currently under construction at the Laboratori Nazionali del Gran Sasso in Italy, aims at detecting dark matter weakly interacting massive particles (WIMPs) with a dual-phase time projection chamber filled with 3300 kg of liquid xenon. The new experiment will be sensitive to a spin-independent WIMP-nucleon scattering cross section of 2 x 10^-47 cm^2 (40 GeV/c^2), nearly two orders of magnitude better than current limits. In this talk I will present the experiment, describe its various subsystems, and report on the current status of the construction.Speaker: Mr Guillaume Plante (Columbia University)
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CUORE: Bolometers at the Frontier of Neutrinoless Double BetaNeutrinoless double beta decay ($0\nu\beta\beta$) is theoretically motivated but has never been observed. It's discovery would demonstrate lepton number violation, establish neutrinos are Majorana fermions and possibly constrain the absolute neutrino-mass scale. The last decade has seen tremendous progress in the search for this decay but to push the frontier forward improved detectors --- with excellent energy resolution, extremely low background, and ton-yr exposures --- are required. CUORE is meeting this challenge with an array of 988 TeO$_{2}$-bolometers. With an active mass of 741~kg, it will be by far the largest ultra-low-temperature bolometer array ever operated. I will describe the bolometer detectors of CUORE and discuss what has been learned from an ongoing prototype experiment, CUORE0. The data demonstates the bolometer performance in terms of energy-resolution and intrinsic background meet the requirements needed for CUORE to achieve it's target 90\%C.L lower-limt sensitivity of \mbox{$T_{1/2}^{0\nu}$ = $9.5\times 10^{25}$~yr.}Speaker: Dr Thomas ODonnell (UC Berkeley / LBNL)
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The Hyper-K Experiment: present and R&D for the next decadeHyper-Kamiokande (Hyper-K), a proposed one-megaton water Cherenkov detector, is the logical continuation of the highly successful program of neutrino (astro)physics and proton decay using the water Cherenkov technique. In its baseline design, the Hyper-K detector consists of two cylindrical tanks lying side-by-side, the outer dimensions of each tank being 48m x 54m x 250m. The inner detector region will be instrumented with 99,000 20-inch photo-sensors. Hyper-K will offer a broad program of physics and astrophysics including precise measurements of the lepton mixing matrix and leptonic CP asymmetry with accelerator and atmospheric neutrinos and searches for nucleon decay. An international collaboration has been intensively working on the R&D of key components such as optimization of cavern and tank construction, development of high performance photosensor, calibration, readout and trigger systems, J-PARC neutrino beam improvement, and development of simulation and reconstruction software. In addition new near detectors are being designed that employ novel techniques to maximise the Hyper-K beam physics potential. An overview of the R&D for Hyper-K and its near detectors will be presented.Speaker: Dr David Hadley (University of Warwick)
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KM3NeT - The next-generation neutrino telescope in the MediterraneanKM3NeT is a multi-site, deep-sea research infrastructure being constructed in the Mediterranean Sea. It will comprise the next generation neutrino telescope and it will offer the opportunity of a variety of multi-disciplinary, real-time measurements. The apparatus will be equipped with a large number of digital optical modules (DOMs), each equipped with 31 PMTs of 3” photocathode, arranged on flexible detection units (DUs). The DUs are deployed on the sea bottom in a compact configuration and are left free to reach their unfurled shape after installation. Two configurations of DUs, each comprising 18 DOMs, have been considered: in the tallest configuration, the spacing between DOMs is of 36 m, for a total height of a DU exceeding 700 m; alternatively, the DOMs can be mounted with a spacing as small as 6 m, allowing to build a detector optimized for lower energies as needed for neutrino mass hierarchy investigations. KM3NeT 2.0 comprises the installation of 230 such units, optimized for high-energy neutrino astrophysics, at a depth of 3500 m offshore Sicily, plus 115 DUs, in the lower-energy configuration, at 2500 m depth offshore Toulon, France (respectively: the ARCA and ORCA projects, i.e. Astroparticle and Oscillations Research with Comics in the Abyss). Following the successful installation of prototypes in the past two years, construction of the first core of the apparatus has started. The technological solutions for KM3NeT and the expected performance will be presented.Speaker: Marco Circella (BA)
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Digital FDIRC: a Focused Differential Internal Reflection Cherenkov imaged by SiPM arraysA prototype of an Internal Reflection Cherenkov detector, with a SiO2 (Fused Silica) radiator bar optically connected to a cylindrical mirror, was tested at CERN SPS in March 2015 with a beam of relativistic ions obtained from fragmentation of primary argon nuclei at energies 13 and 30 GeV/n. The detector, designed to identify cosmic nuclei, features an imaging focal plane of dimensions ~4 cm x 3 cm equipped with 16 arrays of NUV-SiPM (near-ultraviolet sensitive silicon photon avalanche detector) for a total of 1024 sensitive elements. The outstanding performance of the photodetectors (with negligible background in between adjacent photopeaks), allowed to apply the technique of photon counting to the Cherenkov light collected on the focal plane. Thanks to the fine granularity of the array elements, the Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z^2 as a function of the atomic number Z. In this paper, we report the performance of the SiPM arrays and the excellent resolution achieved by the Digital Cherenkov prototype in the charge identification of the elements present in the beam.Speaker: Pier Simone Marrocchesi (University of Siena and INFN Pisa)
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Coffee Break
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Interferometric Readout of a Monolithic Accelerometer, towards the fm/√Hz resolutionThe European Gravitational wave Observatory Virgo is undergoing an upgrade to increase its strain sensitivity to about 3e-24 1/√Hz in the detection band of 10 Hz – 10 kHz. The upgrade for this detector necessitates seismically isolating sensing optics in a vacuum environment that were on an optical bench outside vacuum in previous Virgo configurations. For this purpose, Nikhef has designed and built the five compact isolators, called MultiSAS. To measure the residual motion of the optical components and the transfer function of the isolator in full assembly, no (commercial) sensor is available that has sufficient sensitivity. A novel vibration sensor has been built at Nikhef that features an interferometric readout for a horizontal monolithic accelerometer. It will be able to measure in the vicinity of the fm/√Hz regime from 10 Hz onwards. Current results show unprecedented (self) noise levels around 30 fm/ √Hz from 20 Hz onwards, 1 order of magnitude too high.Speaker: Mr Joris van Heijningen (Nikhef)
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Radio Detection of high-energy cosmic rays with the Auger Engineering Radio Array (AERA)The Auger Engineering Radio Array (AERA) is an enhancement of the Pierre Auger Observatory in Argentina. AERA is the world’s largest antenna array for cosmic-ray observation. It consists of more than 150 antennas detecting the radio signal emitted by air showers, i.e., cascades of secondary particles caused by primary cosmic rays hitting the atmosphere. At the beginning, technical goals had been in focus: first of all, the successful demonstration that a large scale antenna array consisting of autonomous stations is feasible. Moreover, techniques for calibration of the antennas and time calibration of the array have been developed, as well as special software for data analysis. Meanwhile physics goals come in focus. At the Pierre Auger Observatory, air showers are simultaneously detected by several detector systems, in particular water-Cherenkov detectors at the surface, underground muon detectors, and fluorescence telescopes, which enables cross-calibration of AERA. For the direction and energy of air showers, the precision achieved by AERA is already competitive, for the type of the primary particle, several methods are tested and optimized. By combining AERA with the particle detectors we aim for a better understanding of cosmic rays in the energy range from approximately 0.3 to 10 EeV, i.e., significantly higher energies than preceding radio arrays.Speaker: Dr Frank G. Schröder (Karlsruhe Institute of Technology (KIT))
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Deep sky survey of MeV gamma rays due to advanced Electron Tracking Compton Camera (ETCC) with balloon experimentETCC with a TPC and scintillators, by measuring electron tacks, provides a strong background rejection by dE/dx of the track and clear imaging by the arc direction of MeV gammas for MeV Gamma Astronomy. In 2006 its background rejection was revealed by SMILE-I balloon using the dE/dx of tracks. In 2013, 30cm-cube-ETCC was developed to catch gammas from Crab in next SMILE-II balloon with >5$^\circ$ for 4 hrs. Now its sensitivity has been doubled to 10$^\circ$ by attaining the angular resolution of the track (SPD angle) to that determined by multiple scattering of the gas. Thus, we show the ability of ETCC to give a better significance by a factor of ~10 than conventional Compton Cameras by dE/dx and SPD. Based on this technology, a 40cm-cubic ETCC with CF4 gas is expected to provide a 5times better sensitivity than COMPTEL in one month balloon, and 50cm-cube ETCCs would exceed over 10-12 ergcm-2s-1 (1mCrab) in satellite. Here we summarize the performance of SMILE-II ETCC and its future development. To verify, SMILE-II was irradiated by intense gammas and neutron by 140MeV proton, and measured both clear image of a weak RI without the efficiency deterioration under 10times stronger radiation than the balloon altitudeSpeaker: Prof. Toru Tanimori (Graduate School of Science, Kyoto University)
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The superconducting microcalorimeters array for the focal plane of the X-IFU instrument on board of the X-ray observatory AthenaThe Advanced Telescope for High-ENergy Astrophysics (Athena) has been selected by ESA as its second Large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0. 3− 12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with an high filling-factor, high quantum efficiency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-of-the art of the FDM read-out.Speaker: Dr Luciano Gottardi (SRON - Netherlands Institute for Space Research)
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The Spectrometer/Telescope for Imaging X-ray (STIX) on Solar Orbiter: flight design, challenges and trade-offsSolar Orbiter is a Sun-observing mission of the European Space Agency, addressing the interaction between the Sun and the heliosphere, with launch planned for 2018. The Spectrometer/Telescope for Imaging X-rays (STIX), one of ten instruments on-board the spacecraft, will determine the intensity, spectrum, timing, and location of thermal and accelerated electrons near the Sun through their Bremsstrahlung X-ray emission, addressing in particular the emission from flaring regions on the Sun. STIX uses indirect Fourier imaging. The Sun is observed through pairs of fine tungsten grids, separated by 55 cm, that cast a Moire transmission pattern on pixelized CdTe detectors. The source location and morphology will be reconstructed on the ground using the transmitted pixel count rates. The construction of flight-hardware has recently started. This contribution focuses on the instrument and detector challenges, performance limitations, and how they were addressed. The main design constraints comprise a) the limited electrical power (7 W), b) the thermal environment (CdTe passively cooled to -20 deg Celsius embedded in a +50 deg Celsius spacecraft), c) the radiation environment (degradation of CdTe from displacement damage by energetic protons), d) the required long-term reliability (space mission duration of ten years), e) the requirement for autonomous operation over periods of up to 80 days, and f) the low telemetry rates (700 bits per second).Speaker: Dr Oliver Grimm (ETH Zurich, FHNW Windisch)
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Calocube - A highly segmented calorimeter for a space based experiment.Future research in High Energy Cosmic Ray Physics concerns fundamental questions on their origin, acceleration mechanism, and composition. Well known "features" of the energy spectra of cosmic rays such as the "knee" region can provide some of the answers to the above questions. The limits of ground based observations, which rely on sophisticated models describing high energy interactions in the earth's atmosphere, could be overcome by direct measurements in space. A calorimeter based space experiment can provide not only flux measurements but also energy spectra and particle ID, especially when coupled to a dE/dx measuring detector. Unfortunately fluxes at these high energies are extremely low and require very large acceptances if enough statistic is to be collected in a reasonable time. This contrasts with the lightness and compactness requirements for space based experiments. A novel idea in calorimetry is presented here which addresses these issues while limiting the mass and volume of the detector. The proposed calorimeter has a high granularity coupled to a homogeneous segmentation both lateral and in depth. This unique design allows it to achieve excellent distinction between hadrons and electrons while maximizing the acceptance by increasing the number of entry windows to the detector. A small prototype has already being built and tested with ions. In this talk the results obtained will be presented in light of the simulations performed.Speaker: Raffaello D'Alessandro (FI)
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Detector Techniques for Cosmology, Astroparticle and General Physics - Poster Session
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The Tunka Radio Extension (Tunka-Rex) – Radio Measurements of Cosmic Rays in SiberiaThe Tunka observatory is located close to Lake Baikal in Siberia, Russia. Its main detector, Tunka-133, is an array of photomultipliers measuring the Cherenkov light emitted by cosmic-ray air showers. It is used to study cosmic rays up to energies of approximately 1 EeV, which is the energy range of the assumed transition from galactic to extra-galactic cosmic rays. The Tunka Radio Extension (Tunka-Rex) started operation in October 2012. It currently consists of 44 antennas distributed over an area of approximately 1 km². Tunka-Rex measures the radio emission of the same air showers, which are also detected by Tunka-133 and Tunka-Grande, a scintillator extension installed at the site in 2014. Tunka-Rex has mainly three goals: First, the demonstration that radio arrays can be economic. This is achieved by adapting the detection technique to the existing infrastructure at the site. Second, the cross-calibration with the air-Cherenkov measurements, and the determination of the precision for the energy and mass of the primary cosmic-ray particles. Third, cosmic-ray physics at energies close to 1 EeV, where the standard Tunka analysis is limited by statistics. In contrast to the air-Cherenkov measurements, radio measurements are not limited to dark nights with good weather and, therefore, can provide an order of magnitude higher event rate at this energy.Speaker: Dr Frank G. Schröder (Karlsruhe Institute of Technology (KIT))
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TITUS: An Intermediate Distance Detector for the Tokai-to-Hyper-Kamiokande Neutrino Beam and Physics with GadoliniumThe Tokai Intermediate Tank for Unoscillated Spectrum (TITUS) detector is a proposed addition to the Hyper-Kamiokande (Hyper-K) experiment, located approximately 2 km from the J-PARC neutrino beam. The design consists of a 2 kton Gd-doped water Cherenkov tank, partially covered by a magnetised muon range detector. The target material and location were chosen so that the neutrino interactions and beam spectrum at TITUS would match those of Hyper-K. Including a 0.1% Gd concentration allows for nu/antinu discrimination via neutron tagging. The primary goal of TITUS is to measure the neutrino spectrum at the near detector with a very high precision, thus improving the Hyper-Kamiokande CP violation sensitivity. TITUS is also able to precisely measure cross section as a function of the neutron multiplicity and can be used for physics unrelated to the J-PARC beam, functioning as an independent detector for supernova neutrino bursts and measuring the neutron rate to improve Hyper-K proton decay searches. Also, a more general overview on the physics with gadolinium both for high and low energy physics and synergy with other worldwide programmes will be given.Speaker: Dr David Hadley (University of Warwick)
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Search for sterile neutrinos at the ILL reactorThe goal of the Stereo experiment is to answer the question of the existence of a sterile neutrino with a mass around 1 eV. The proposed measurement will take place at short distance from the research reactor of ILL in Grenoble. If a sterile neutrino exists then one should observe a distortion of the energy spectrum of the reactor electron antineutrinos induced by the mixing with the new sterile state. The detection concept is based on the interaction of the antineutrinos in a liquid scintillator (LS) via the inverse beta decay process. The target volume consists in 6 cells stacked along the direction of the core. They are filled with Gadolinium (Gd) -doped LS to tag the radiative neutron capture on Gd in coincidence with the annihilation of the positron. An outer crown, filled with LS without Gd, recovers part of the escaping gammas to improve the detection efficiency and the energy resolution. The light emits by the reaction is collected by 54 photomultipliers (PMT), placed at the top of the vessel. The optically coupling between the LS and the PMT is realized thanks to acrylics blocks . To collect the maximum of the light emitted, an acrylic aquarium which is comprising within a reflector foil is placed inside the internal vessel. The CEA Irfu team is in charge of the design, the realization and the integration of the inner detector of the experiment.Speaker: Caroline Lahonde-hamdoun (cea)
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Ultra-Sensitive γ-Ray Spectroscopy Set-Up for Investigating Primordial Lithium Problem.To precisely determine BBN 6Li production, the cross section of the nuclear reaction $^2$H(α,γ)$^6$Li must be directly measured within the astrophysical energy range of 30-400 keV. Since the cross section is of the order of nanobarn, the expected counting rate is very low indeed, therefore this measurement requires an ultra-low γ-ray background in the experimental set-up. We have realized the conditions matching these very strict requirements at LUNA, the deep underground accelerator laboratory active in the INFN Gran Sasso National Laboratory (LNGS), Italy, exploiting 1400 m of rock as a powerful passive shield from cosmic ray. This leads to a reduction of the muon flux, the most penetrating component of the cosmic-rays, by a factor 106 compared to the surface. At LUNA is running an electrostatic continuous beam 400 kV accelerator that provides an α beam of 0.3 mA of average luminosity. The nuclear reactions are induced in a windowless differentially pumped gas target filled with up to 0.3 mbar high purity deuterium gas, with on-line feed back control of gas pressure. We present and discuss the γ-ray background reduction reached in the HPGe spectrometer.Speaker: Dr Gianpiero Gervino (Dipartimento di Fisica and INFN Torino)
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The rearch of aging test for the 20inch MCP-PMTMicrochannel plate (MCP) adsorbed plenty of gases when it is produced. We had degased in the manufacture of MCP-PMT, but it isn't enough, it still affect the parameters of the MCP-PMT. We raerch the aging test of the MCP-PMT to stabilize the parameters of the MCP-PMT. Aging test condition and procedure :put the MCP-PMT in the Camera obscura and it continuous operated with the voltage of 2500V, we test the gain ``dark noise''. Single photoelectron spectrum peak-to-valley ratio(P/V) every day,after 6 days. We found that the gain decreased from 0.87E7 to 0.64E7,dark noise decreased from 35.8K/s to 14.2K/s, P/Vdecreased from 3.7 to 2.7, we continuous operate MCP-PMT more than 10 days, the parameters keep stabilization. We considered that the aging test is effective worked for the MCP-PMT parameters and when it was at aging test, the electrons can remove the gas adhere to the MCP. The aging test of 20inch MCP-PMT is the first attempt, it is good for us to rearch the MCP-PMT.Speakers: Prof. Dong Li (Institution: North Night Vision Technology Co.,Ltd Nanjing Branch), Prof. Shuguang Si (Institution: North Night Vision Technology Co.,Ltd Nanjing Branch)
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The POLIS interferometer for ponderomotive squeezed light generationPOLIS is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states, of light, and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In the poster the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.Speaker: Martina De Laurentis (NA)
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The Large Synoptic Survey Telescope Corner Raft Readout ElectronicsThe Large Synoptic Survey Telescope (LSST) instrument consists of a main science array of 189 4K x 4K CCDs and four guiding and wavefront sensing subsystems located at the four corners of the instrumented field of view. Each wavefront/guiding subsystem comprises a pair of 4K x 4K guide CDDs and a pair of offset 2K x 4K wavefront curvature sensors. The guide CCDs read a region of interest (ROI) of 50 x 50 pixels with a rate of 9Hz, whereas the wavefront curvature CCDs are read at the same cadence of the main camera system, providing 15 sec integrations with 2 sec readout. The corner raft readout electronics is located directly behind the CCDs inside the camera vacuum vessel and includes ASICs for readout and clock generation, multiple 18bit ADCs for the video signal chain and an FPGA for sequence generation, data capture and communication. One PCB will serve the guide functionality and another PCB will serve the wavefront functionality. All communication with the corner raft readout electronics is performed via a high speed serial link to keep the necessary vacuum penetrations. For the same reason the power interface is designed to operate from a minimum of external voltages. An overview of the hardware and electronics of this LSST subsystem will be given.Speaker: Sven Herrmann (SLAC)
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The EEE Project: an extended network of muon telescopes for the study of cosmic raysThe EEE (Extreme Energy Event) Project is an experiment to study high energy extensive air showers (EAS) over a very large area, using an array of muon telescopes, based on positionsensitive Multigap Resistive Plate Chambers. Each telescope is composed by three MRPC, with an active area of 0.82 x 1.58 m2. Each chamber is segmented into 24 strips, and a readout at the two ends. Strip size and measurement of the time difference at the two ends, provide an overall spatial resolution of about 7 mm along the two coordinates. A VME-based data acquisition include a trigger card, 144 TDC channels and a GPS unit for remote synchronization. At present the array is composed of more than 40 stations, located in Italian high schools, INFN sections (total area 3 x 105 km2) and at CERN, and most of them were independently taking data since several years. A new combined run (RUN 1) has started in February 2015, with more than 20 telescopes taking data simultaneously and a collected statistics larger than 5 x 109 reconstructed events. An overview of the experiment, experience on a several year running period and some results from physics analyses will be given. Studies on correlated muons from the same EAS in many metropolitan areas, for distances up to ~2 km, solar events and Forbush decreases observed at the same time by several stations, upgoing low energy tracks and angular distributions of the detected muons, also making use of equatorial coordinates, will be shown.Speaker: Ms Maria Paola Panetta (INFN Lecce)
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The Archimedes ExperimentArchimedes is an INFN funded pathfinder experiment aimed at verifying the feasibility of measuring the interaction of vacuum fluctuations with gravity. The final experiment will measure the force exerted by the gravitational field on a Casimir cavity whose vacuum energy is modulated with a superconductive transition, by using a balance as a small force detector. Archimedes is devoted to test the most critical experimental aspects, in particular the balance resonance frequency and quality factor, the thermal modulation efficiency and the superconductive sample realization.Speaker: Dr Paola Puppo (ROMA1)
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The Advanced Virgo monolithic fused silica suspensionThe detection of gravitational waves is one of the most challenging prospects faced by experimental physicists. Suspension thermal noise is an important noise source at operating frequencies between approximately 10 and 30 Hz, and represents a limit to the sensitivity of the ground based interferometric gravitational wave detectors. Its effects can be reduced by minimizing the losses and optimizing the geometry of the suspension fibre and its attachment system. In this poster we will present the design of last suspension system for use in the Advanced Virgo (AdV) detector, describing the design of the double stage monolithic suspension. With the help of a finite element model, we also present a full thermal noise analysis, taking into account for the precise geometry of the fibers attachment systems on the suspension elements. We shall demonstrate the suitability of this suspension for installation in AdV.Speaker: Dr Paola Puppo (ROMA1)
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Test of Weak Equivalence Principle on Antimatter with AEgISThe AE$\bar\textrm{g}$IS experiment plans to perform a direct measurement of the gravitational acceleration $\bar g$ of antihydrogen in the gravitational field of the Earth and thus test the validity of the weak equivalence principle on antimatter. The production of antihydrogen will be performed by combining the advantages of pulsed charge-exchange reaction between highly excited positronium metastable atoms and cold antiprotons that are trapped in a cryogenic Penning trap. Once created, the excited antihydrogen atom will be formed into an anti-atom beam via the use of inhomogeneous electric fields. The deflection of this anti-atom beam due to gravity will be measured by using the moiré deflectometer gratings and a position sensitive detector at micrometer precision. While still in construction and development phase, AE$\bar{\text{g}}$IS started taking preliminary data since 2012. We present an overview of the experiment, describe its current status and show some of the recent results with antiprotons including the studies of direct low energy antiproton annihilation in silicon and nuclear emulsion detectors. We also show the results of a successful extension of an atom optics tool (the moiré deflectometer) for the measurement of small electromagnetic forces acting on slow antiprotons. This proof-of-principle measurement shows the feasibility and strength of such detection technique for the foreseen gravity measurement in AE$\bar{\text{g}}$IS.Speaker: Daniel Krasnicky (GE)
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Possible usage of Cherenkov photons to reduce the background in a 136Xe neutrinoless double-beta decay experimentOne of the main backgrounds in the search for 129Xe nutrinoless double-beta decay (0$\nu\beta\beta$) is the signal from Compton scattering of photons with energy around the decay end point at 2.458 MeV. One efficient method to exclude this background is by self-shielding, resulting in a waste of active volume. Another proposed method is tagging the daughter barium nucleus, which relies on the capture and detection of single Ba ions to identify a Xe 0$\nu\beta\beta$ decay. This is an extremely challenging task and, although feasible, presently suffers of very low efficiency. Electrons in liquid xenon emit scintillation light at 175~nm, but liquid xenon is extremely transparent to ultra violet light. It is in principle possible to discriminate one particle events (Compton background) from two particle events (double-beta decay signals) by the amount of Cherenkov radiation emitted. The identification of the Cherenkov photons may be performed by looking at the different time structure of the signal with respect to the scintillation, by selecting photons with wavelengths larger than the typical Xenon scintillation light, and by the different emission topology. The efficiency of this discrimination, albeit small, can be comparable to that of barium tagging. A proof-of-principle study of this approach is presented here together with preliminary studies on possible detectors for the two light components at different wavelengths.Speaker: Giovanni Signorelli (PI)
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Phase camera experimentWe will report a study of the phase camera, which is a wave-front sensor of laser. Especially, this sensor is utilized for observing phase-modulated laser in an interferometer of gravitational wave (GW) detectors. We are preparing this phase camera for advanced VIRGO and its installation is on going. The sideband signals in power recycling cavity are easily degraded by mirror aberrations in VIRGO. The phase camera will be used to see such mirror aberrations through the wave front of sidebands, and then, a cancellation pattern of the aberrations is constructed on compensation plates using CO2 lasers as a thermal compensation system.Speaker: Dr Kazuhiro Agatsuma (National Institute for Subatomic Physics)
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Measurement of a polarised gamma ray beam from 1.7 to 74 MeV with the HARPO TPCGamma-ray astronomy allows us to explore the non-thermal emissions of objects such as Active Galatic Nuclei (AGN), Gamma Ray Bursts (GRB) and pulsars. Current gamma-ray telescopes based on photon conversion to electron-positron pair use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. A gaseous detector can achieve higher angular resolution in the MeV-GeV range thanks to reduced multiple scattering. This gives access to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. The HARPO Time Projection Chamber (TPC) has been designed as a high angular resolution telescope for gamma-ray polarimetry. It was set up in a polarised gamma-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The full experimental setup of the TPC and the photon beam will be described. The first results from the beam campaign will be shown.Speaker: Dr Philippe Gros (LLR, Ecole Polytechnique)
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INFN Camera demonstrator for the Cherenkov Telescope ArrayThe Cherenkov Telescope Array is a world-wide project with the aim of exploring the highest energy region of the electromagnetic spectrum. Two arrays will guarantee the full sky coverage in the energy range from few tens of GeV to hundreds of TeV, with improved angular resolution and a sensitivity in the TeV energy region better by one order of magnitude than the currently operating arrays. Three different telescope types have been envisaged, with different mirror sizes and focal plane features. A silicon photomultiplier (SiPM) based camera is being proposed as a solution to match the pixel angular size of ~ 0.17 degrees. INFN is developing a camera demonstrator made by 9 Photo Sensor Modules (PSMs, 64 pixels each, total coverage ~ 1/4 of the full focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near UltraViolet High Fill factor SiPMs and a Front-End Electronics (FEE) based on Target 7 ASIC, a 16 channels fast digitizer (up to 2GS/s) with buffer and self-trigger capability specifically developed for this purpose. The pixel dimension of 6x6 mm^2 leads to a very compact design with challenging problems of thermal dissipation. A modular structure, made by copper frames hosting one PSM and the corresponding FEE inserted in an aluminium structure, has been conceived, with a water cooling system to keep the required working temperature. The actual design, the adopted technical solutions and the achieved results for this demonstrator are presented and discussed.Speaker: Riccardo Paoletti (SI)
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Experimental study of breakdown electric fields in liquid argonThe last decade has seen an increase in the importance and application of liquified noble gases as detecting medium, both in the dark matter search and accelerator-based neutrino experiments. Especially in the latter field, Liquid Argon Time Projection Chambers (LArTPCs) are promising candidates for future short and long baseline oscillation experiments. Hence, characterization of both LArTPCs and liquid argon properties results crucial for the successful realization of multi-kiloton scale detectors. In this talk I report on systematic studies of breakdown electric fields in liquid argon as a function of argon purity, cathode - anode distance and electrode size performed at Fermilab. The results exhibit a geometric dependence of the electric field strength at breakdown. This is the first time that such a dependence has been shown for liquid argon.Speaker: Dr Roberto Acciarri (FNAL)
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Evaluation of Photo Multiplier Tube Candidates for the Cherenkov Telescope ArrayPhoto Multiplier Tubes (PMT) are the most wide spread detectors for fast, faint light signals. Some five years ago, an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project was started with the companies Hamamatsu Photonics K.K. (Japan) and Electron Tubes Enterprises Ltd. (England). CTA is the next major Imaging Atmospheric Cherenkov Telescopes array for high energy gamma-ray astrophysics. For CTA we need PMTs with outstanding good quantum efficiency, high photo electron collection efficiency, short pulse width, very low after-pulsing and transit time spread. Both manufacturers were able to produce outstanding PMTs with an enhanced peak quantum efficiency of ~ 40%, which can collect up to 95-98% of photo electrons onto the first dynode for the wavelengths ≥ 400nm. The pulse width averages around 3ns at the selected operational gain of 40000. Also, the after-pulsing for a set threshold level of ≥ 4 photo electrons is significantly reduced, down to 0.02%. We will report on the measurements of PMT R-12292-100 from Hamamatsu as the final version and the PMT D573KFLSB as one of the latest test versions from Electron Tubes Enterprises as candidate PMTs for the CTA project.Speaker: Mr Dominik Müller (Max-Planck-Institute for Physics)
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Euso Balloon: the first flightEUSO-Balloon is a pathfinder mission for JEM-EUSO (Extreme Universe Space Observatory on-board the Japanese Experiment Module), the near-UV telescope proposed to be installed on board the International Space Station (ISS) before the end of this decade. The main objective of this pathfinder mission is to perform a full scale end-to-end test of all the key technologies of JEM-EUSO detectors and to measure the UV background . The JEM-EUSO instrument consists of an UV telescope designed to focus the signal of the UV tracks generated by Extreme Energy Cosmic Rays propagating in Earth’s atmosphere, onto a finely pixelized UV camera. The EUSO-Balloon instrument, smaller than the one designed for the ISS, was launched on August 2014 from Timmins (Ontario, Canada). The flight lasted about five hours and the instrument reached a float altitude of about 40 km. From this altitude the telescope registered, at a rate of 400’000 frames/sec, the nightglow background on forests, lakes and clouds, as well as city lights and artificial air showers tracks generated by means of a laser installed on an helicopter flying inside its field of view. In this contribution we will describe the instrument and its performance during the flight.Speaker: Dr Valentina Scotti (INFN Napoli)
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EUSO-TA prototype telescopeEUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. EUSO-TA consists of two 1 m squared Fresnel lenses, with a field-of-view of 11°. The lense system focuses the light on a Photo Detector Module (PDM), identical to those (137) that will form the JEM-EUSO focal surface. The PDM currently consists of 36 Hamamatsu multi-anode photomultipliers (MAPMTs) with 64 channels each, for a total of 2304 channels. Front-End readout is performed by 36 ASICS, with trigger and readout tasks performed by two FPGA boards that send the data to a CPU and a storage system. The detector was installed in February 2015 and tests using the mentioned light sources have been performed successfully, as well as observations of stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a PDM. The response of this sensor type is investigated by simulations and in the laboratory.Speaker: Ms Francesca Bisconti (Karlsruhe Institute of Technology)
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Development of a super-resolution optical microscope for directional Dark Matter search experimentThe Dark Matter (DM) existence is one of the most open and discussed questions nowadays. The best candidates are so-called Weakly Interactive Massive Particles (WIMPs) with mass ranging from few GeV to a few TeV that interact with ordinary matter with cross sections typical or smaller than that of the weak processes. The motion of the Sun inside the galaxy causes an anisotropy in direction of WIMP-induced nuclear recoils, and, as it has never been observed, its evidence would unambiguously prove the existence of WIMP particles as DM constituents, which makes the directional DM search an extremely interesting and important issue from the point of view of fundamental science. Nuclear emulsion is a perfect choice for a detector for directional DM search because of its high density and the best position accuracy. The track length of recoil nuclei in emulsion is of the order of 100 nm, making the resolution of conventional optical microscopes insufficient to resolve them. Here we report about the R&D on a super-resolution optical microscope to be used in a future directional DM search experiment with nuclear emulsion as a detector media. The microscope will be fully automatic, will use novel image acquisition and analysis techniques, will achieve the spatial resolution of the order of few tens of nm and will be capable of reconstructing recoil tracks with the length of at least 100 nm with high angular resolution.Speaker: Andrey Alexandrov (NA)
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A simple technique for gamma ray and cosmic ray spectroscopy using plastic scintillatorA simple and new technique has been developed for gamma ray and cosmic ray muon pulse height spectroscopy without using SCA or MCA. Only scintillator detector, a leading edge discriminator and a NIM scaler have been used in this technique. Gamma ray spectrum has been obtained for Co60 and Cs137 sources. Proportionality in energy and pulse height has been observed. The energy resolution for the detector has been found to be 9.3% and 7.6% for the Co60 1.17 MeV and 1.33 MeV peak respectively and 10.2% for 662 keV peak of Cs137. Cosmic ray muon pulse height spectrum has been obtained for two scintillators and fitted with Landau distribution. The most probable energy deposition in 1 cm thick plastic material has been found to be ∼ 1.4 MeV. Although the energy resolution is not so good but still using plastic scintillator detector gamma spectroscopy and cosmic ray muon pulse height spectroscopy can be done. Main drawback of this technique is that this process is time consumable and may not be useful for real experiment; however, this process is very useful and can be applied for laboratory measurement where MCA or SCA are not available.Speakers: Ms SHARMILI RUDRA (University of Calcutta), Dr Saikat Biswas (National Institute of Science Education and Research)
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A scintillating bolometer array for double beta decay studies: the LUCIFER experimentThe main goal of the LUCIFER experiment is to study the neutrinoless double beta decay, a rare process allowed if neutrinos are Majorana particles. Although aiming at a discovery, in the case of insufficient sensitivity the LUCIFER technique will be the demonstrator for a higher mass experiment able to probe the entire inverted hierarchy region of the neutrino mass. In order to achieve this challenging result high resolution detectors with very low background and active background discrimination capability are required. This very interesting possibility can be largely fulfill by scintillating bolometers thanks to the simultaneous read-out of heat and light emitted by the interactions in the detector or by pulse shape analysis. The LUCIFER setup will consist of an array of individual module detectors, arranged in a tower-like structure. Each module will be composed by a ~0.5 kg scintillating crystal equipped with a Ge-crystal light detector operated as bolometers at ~10 mK. We will present an overview on LUCIFER and the results obtained with a single module. Finally, we will also report on the first bolometric measurement of the two neutrino double beta decay of 100Mo obtained with ZnMoO4 crystals.Speaker: Luca Gironi (MIB)
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CalorimetryConveners: Prof. David Hitlin (Caltech), Prof. Junji Tojo (Kyushu University)
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The Next Generation of Crystal Detectors in High Energy Physics ExperimentsCrystal detectors have been used widely for decades in high energy and nuclear physics experiments, medical instruments and homeland security applications. Novel crystal detectors are continuously being found. Future HEP experiments require bright and fast crystal detectors with excellent radiation hardness. Cost-effectiveness is also a crucial issue for crystal detectors to be used in a large volume. To face these new challenges a thorough R&D program is required to investigate and develop crystal detectors for future HEP experiments in all frontiers.Speaker: Dr Ren-yuan Zhu (Caltech)
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Recent Developments on Scintillating Crystal Fibers for Calorimetry ApplicationsThe recent progress in the micro-pulling-down technique allows heavy scintillating crystals to be grown directly into a fiber geometry of variable shape, length and diameter. Examples of materials that can be grown with this technique are Lutetium/Yttrium Aluminum Garnets. Thanks to the flexibility of this approach, combined with the high density and good radiation hardness of the material, such a technology represents a powerful tool for the development of future calorimeters. In this work, the most recent results for LuAG:Ce and YAG:Ce fibers are presented. In particular, the tolerance to radiation and the use of co-dopants to improve the scintillation time response are discussed, these two aspects being amongst the most important challenges to be faced for operation in the harsh radiation environment of the next phase of LHC. As an important proof of concept of the application of crystal fibers in future experiments, a small calorimeter prototype was built and tested on beam in March 2014 at the Fermilab T-1041 beam line. A grooved brass absorber was instrumented with 64 LuAG fibers. Each fiber was readout individually using SiPMs, thus providing a highly granular description of the shower development inside the module as well as good tracking capabilities. The performance of the module was tested using electrons and pions in the 2-32 GeV energy range. Physics results from this beam test will be presented, together with further ideas for fiber calorimeter prototypes.Speaker: Mr Andrea Davide Benaglia (CERN)
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Design and status of the Mu2e electromagnetic calorimeterhe Mu2e experiment at FNAL aims to measure the conversion of a $\mu^-$ to an electron, resulting in a mono-chromatic $e^-$ signal with an energy of $\sim$ 105 MeV, and reach a single event sensitivity of ~ $2.5 \times 10^{-17}$ in three years of running. The calorimeter has to perform $\mu$/e particle identification, support/improve the tracking pattern recognition and provide a tracking independent software trigger for the experiment. It should be able to keep functionality in an environment where the n, p and $\gamma$ background, from muon capture processes and beam flash events, deliver a maximum dose of ~ 120 Gy/year. It should also work in 1 T axial magnetic field and a $10^{-4}$ torr vacuum. These requirements ask for a calorimeter with large acceptance for signal events and a reasonable energy O(5\%) and time O($<$ 500 ps) resolution. Due to the sudden LYSO cost increase, the baseline calorimeter version is now composed of two disks of $\sim$ 900 BaF$_2$ crystals. This choice matches the requirement of fast, high resolution and radiation hardness crystals. Each cell is read out by two APDs whose signals are amplified, shaped and readout through 200 msps waveform digitizers. We show the calorimeter design, the results obtained at 100 MeV with a small size LYSO prototype, to test a first version of calorimeter system integration, and the $R\&D$ and simulation carried out to prove the validity of the new baseline.Speaker: Stefano Miscetti (LNF)
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A pure CsI Calorimeter for the BelleII experiment at SuperKEKBThe new facility SuperKEKB will be an upgrade of the existing KEKB electron-positron asymmetric collider, with a target luminosity of 8 x 10^35 cm^-2 s^-1, about 40 times greater than that of KEKB. The accelerator upgrade is based on the novel low-emittance "nanobeams" scheme. The detector will also be upgraded to cope with the higher luminosity, pile-up and occupancy. We report here on the design and development of the new pure CsI calorimeter for the forward region. An intensive R&D has been carried on to study the performance of pure CsI crystals with APD’s (Avalanche Photodiodes) readout. Results about the signal to noise ratio of this detector for different front end electronics configurations will be presented. A matrix of 16 crystals has been put on electron beam at the BTF facility in Frascati. Results in terms of energy and timing resolution of this prototype of the detector will also be discussed.Speaker: Alessandro Rossi (PG)
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4:55 PM
Coffee Break
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Upgrade of the MEG liquid xenon calorimeter with VUV-light sensitive large area SiPMsThe MEG experiment searches for the muon lepton flavor violating decay, $\mu^+\to e^+\gamma$. An upgrade of the experiment is ongoing, aiming to reach a sensitivity of Br($\mu^+\to e^+ \gamma$) = $5\times10^{-14}$, an order of magnitude better than the sensitivity of the current MEG. To achieve this goal, all of the detectors are being upgraded. In MEG, the energy, position and timing of the gamma ray were measured by a liquid Xe calorimeter, which consists of 900 $l$ of liquid Xe and 846 2-inch round-shaped photo-multiplier tubes (PMTs). In the upgrade, the granularity at the gamma ray incident face will be improved by replacing 216 PMTs with 4092 SiPMs (MPPCs) with an active area of 12$\times$12 mm$^2$ each. The energy resolution for the gamma ray is expected to improve by a factor of 2, because the efficiency to collect scintillation light will become more uniform. The position resolution is also expected to improve by a factor of 2. In collaboration with Hamamatsu Photonics K. K., we have successfully developed a high performance MPPC for our detector. It has excellent photon detection efficiency for the liquid xenon scintillation light in VUV range. The size of the chips is large so that it can cover large area with a manageable number of readout channels. The characteristics of the MPPCs are being tested in liquid Xe, and also at the room temperature. The results of the tests will be presented, together with the expected performance of the upgraded detector.Speaker: Dr Kei Ieki (University of Tokyo)
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New results from the RD52 (DREAM) projectSimultaneous detection of the Cherenkov light and scintillation light produced in hadron showers makes it possible to measure the electromagnetic shower fraction event by event and thus eliminate the detrimental effects of fluctuations in this fraction on the performance of calorimeters. In the RD52 (DREAM) project, the possibilities of this dual-readout calorimetry are investigated and optimized. In this talk, the latest results of this project will be presented. These results concern tests of a dual-readout fiber calorimeter with electrons at very small angles of incidence, detailed measurements of the time structure of hadron showers in this detector, as well as elaborate comparisons of various aspects of the calorimeter performance with GEANT4 simulations.Speaker: Prof. Richard Wigmans (Texas Tech University)
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Precision Timing Calorimetry for High Energy PhysicsThe High Luminosity upgrade of the Large Hadron Collider (HL-LHC) and potential future Hadron Colliders operating at even higher energies will deliver unprecedented instantaneous luminosities. The detectors have to cope with a very high rate of simultaneous collisions, referred to as pile up (PU). A powerful mitigation technique uses detectors with excellent time resolution which allows association of particles to primary interactions utilizing the time-of-flight information. In this context we present studies of scintillator based calorimeter technology with the aim to achieve particle detection with a time resolution of a few 10 ps for high energy electrons. We present results from a prototype of a 1.4x1.4x11.4 cm3 sampling calorimeter cell consisting of tungsten absorber plates and Cerium-doped Lutetium Yttrium Orthosilicate (LYSO) scintillator plates. The LYSO plates are read out with wave lengths shifting fibers which are optically coupled to photo detectors on both ends. The timing performance of several photo detectors was characterized. The photo detectors tested were conventional photomultiplier tubes (PMTs), silicon photomultipliers (SiPMs), and microchannel plate PMTs (MCP-PMTs). The measurements were performed at the Fermilab Test Beam Facility, the CERN test beam and at Caltech. As a benchmark setup we use MCP-PMTs to further characterize the timing properties of the high energy showers and other experimental effects. We also present measurements with a fast laser to characterize the response of the prototype and the photo sensors. These measurements are part of an R&D program towards a large scale electromagnetic calorimeter with a time resolution on the order of 10 picoseconds, to be used in high energy physics experiments.Speaker: Adi Bornheim (CALTECH)
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Performances of the SDHCAL hadronic calorimeter for future lepton collider experimentsHadronic calorimeter using GRPC as active medium is proposed in the ILD project of the future ILC experiments. A prototype of 1.3 m3 was built within the CALICE collaboration to validate the option proposed for ILD. The prototype is made of 50 GRPC detector of 1m2 size and 3 mm thickness each. They are fully equipped with a semi-digital electronic readout embedded on the detectors. A new genuine gas distribution design is elaborated to optimize the gas circulation within the detectors. The detectors are placed in a self-supporting mechanical structure playing the role of the absorber. The prototype was exposed to pion and electron beams at CERN in 2012 and in 2014 using the triggerless and the power-pulsing modes. This is the first time a prototype of this size is run with these both modes and until now the unique one. New techniques were developed to extract the energy of the hadron producing the hadronic showers in the prototype. An excellent energy resolution was obtained by analyzing the collected data during the Test Beams at different energies. The ultra-granularity of the SDHCAL allows also a better understanding of the hadronic showers. In addition MIPs produced within the hadronic showers are easily extracted using Hough Transform and used for the insitu study of the detector. The results obtained so far show the big potential of such a high granular calorimeter and pave the way for the use of this new generation of calorimeters in the future experimentsSpeaker: Mr imad laktineh (ipnl)
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Calorimetry - Poster Session
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The design of a photodetector unit of a new Shashlyk EM calorimeter for COMPASS IIA nine-channel photodetector unit with micropixel avalanche photodiodes (MAPD) and precision thermostabilization based on the compact Peltier element is designed and constructed. MAPD-3N with superhigh pixel density 15000 per square mm and area 3×3 mm manufactured by the Zecotek Company were used.Speaker: Dr Igor Chirikov-Zorin (JINR)
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Upgrade of the ATLAS Tile Calorimeter for the High luminosity LHCThe Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal will undergo a major replacement of its on- and off-detector electronics for the high luminosity programme of the LHC in 2024. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and shipped to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies will determine which option will be selected. Field Programmable Gate Arrays (FPGAs) are extensively used for the logic functions of the off- and on-detector electronics. One hybrid demonstrator prototype module with the new calorimeter module electronics, but still compatible with the present system, is planned to be inserted in ATLAS by the end of 2015.Speaker: Dr Giulio Usai (Arlington UT)
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Time performances and irradiation test of CsI crystals readout by MPPCAs an alternative of the crystal choice for the Mu2e calorimeter, we have tested single crystals of pure CsI in combination with large area MPPC from Hamamatsu. The MPPC under consideration, consisting of an array of 16 3$\times$ 3 mm$^2$ cells, 50 $\mu$m pixels, grants an active area of 12$\times$12 mm$^2$ and has an improved PDE reaching $\sim$ 40 \% down to 250 nm thus well adapting to the emission spectra of these crystals. We have measured the light yield, the longitudinal response uniformity and the time performances of CsI crystals procured from three different firms. We have also determined their radiation hardness to a ionization dose of up to 100 krad and to a neutron flux of up to 10$^{11}$ n/cm$^2$.Speaker: Raffaella Donghia (LNF)
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The Calibration system of the Muon G-2 Experiment at FermilabThe muon anomaly (g-2)/2 has been measured to 0.54 parts per million by E821 experiment at Brookhaven Lab, and at present there is a 3 to 4-standard deviation difference between the SM and experimental values. A new muon (g - 2) experiment, E989, is being prepared at Fermilab that will improve the experimental error by a factor of four to clarify this difference. A central component to reach this fourfold improvement in accuracy is the high-precision laser calibration system which should monitor the gain fluctuations of the Calorimeter Photodetectors at 0.04% accuracy. I will review this system, focusing on the technical challenges, solutions, and achievements obtained so far.Speaker: Graziano Venanzoni (LNF)
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Test beam results with a sampling calorimeter of cerium fluoride scintillating crystals and tungsten absorber plates for calorimetry at the HL-LHCA sampling calorimeter using cerium fluoride scintillating crystals as active material, interleaved with absorber plates made of tungsten,and read out by wavelength-shifting fibers has been studied as a calorimeter option for detectors at the upgraded LHC collider at CERN. A prototype has been exposed to high-energy electron beams at the CERN SPS H4 beam line, as well as to lower-energy beams at the INFN Frascati Beam Test Facility in Italy. Results from the studies performed on the prototype will be presented, with energy resolution as the main focus.Speaker: Simone Gelli (R)
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Test beam results of micro channel plates in "ionisation mode" for the detection of single charged particle and electromagnetic showersIMCP is an R&D project aimed at the exploitation of secondary emission of electrons from the surface of micro-channel plates (MCP) for fast timing of showers in high rate environments. The usage of MCPs in "ionisation" mode has long been proposed and is used extensively in ion time-of-flight mass spectrometers. What has not been investigated in depth is their use to detect the ionizing component of showers. The fast time resolution of MCPs exceeds anything that has been previously used in calorimeters, and, if exploited effectively, could aid in the event reconstruction at high luminosities. Results from tests with electrons with energies up to 150 GeV of MCP devices with different characteristics will be presented, in particular detection efficiency and time resolution.Speaker: Paolo Meridiani (ROMA1)
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Research of pure CsI crystal readout by APD for ECL end cap of BELLE IIBELLE II is the upgrade of BELLE by 40 times luminosity, investigating the CP-violation effects. In order to cope with the extremely high luminosity at Belle II, utilizing fast pure CsI scintillation crystals at end cup of ECL has been proposed. Silicon avalanche photodiodes (APD) are considered as a candidate of photosensitive elements to get the acceptable level of the electronic noises. In University of Tokyo, a counter with one pure CsI scintillation crystal coupling one or two or four APD has been studied. The shot noise, thermal noise and addition noise are measured respectively. The total ENC (equivalent noise charge) has been calculated and compared with the value measured experimentally. By calibration of the cosmic ray, the ENE (equivalent noise energy) of the counter has also been measured. We confirm that with pure CsI scintillation crystals readout by 2 S-8664-1010 APDs, the expectation of total noise at 0.6 MeV can be obtained.Speaker: Yi-Fan Jin (University of Tokyo)
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Radiation Damage Induced by 800 MeV Protons in Fast Crystal ScintillatorsThis paper reports charged hadron induced radiation damage in crystal scintillators using 800 MeV proton beam at the WNR facility of LANSCE. A 20 cm long LYSO crystal, a 14 cm long CeF3 crystal and four liquid scintillator based sealed quartz capillaries were irradiated to the level of 1014 p/cm2 by 800 MeV protons in the WNR facility of LANSCE. The results show that the emission weighted radiation induced absorption in the 20 cm long LYSO crystal is about 1 m-1 after 3.3 × 1014 p/cm2, indicating excellent radiation hardness of LYSO against charged hadrons.Speaker: Liyuan Zhang (California Institute of Technology)
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Performance results of a high-granularity electromagnetic calorimeterA compact high-granularity electromagnetic calorimeter prototype has been built to perform generic R&D for an upgrade proposal of a forward calorimeter (FoCal) in the ALICE experiment, which should have very good gamma/π0 discrimination capabilities. The prototype is a Si/W sampling calorimeter using CMOS sensors of the MIMOSA type with a pixel pitch of 30 micron and binary readout with a total of ~39 million pixels. We will report on performance studies of the prototype with test beams at DESY and CERN in a broad energy range. The results of the measurements demonstrate a very small Moliere radius (~11mm) and good linearity of the response. Also results on the detailed shower shape, both longitudinal and lateral, will be presented. We will compare the measurements to GEANT-based MC simulations, which additionally include a modelling of charge diffusion. The studies show the extremely high potential of this technology for future calorimeter development.Speakers: Mr Chunhui Zhang (Utrecht University), Prof. Thomas Peitzmann (Utrecht University/Nikhef)
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Micro-channel Plate Phototubes Used as a Fast EM Shower Maximum DetectorWe present a study of micro-channel plate photomultipliers (MCP-PMT) as the active element of an electromagnetic shower maximum (SM) detector. Results for Photek 240 and Photonis XP85011 MCP-PMT devices were obtained at the Fermilab Test Beam Facility. The time resolutions obtained for this new type of SM detector is at the level of ~12 ps for Photek 240 and ~27 ps for Photonis XP85011 with individual pixel readout. The MCP-PMT showed essentially 100% efficiency for shower detection. No significant dependence of the time resolution on the absorber thickness was observed. We also performed tests where the photocathode was reverse biased, showing that the micro-channel plate alone works as a SM detector and gives 40 ps time resolution.Speaker: Dr Erik Ramberg (Fermilab)
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Calorimetry at CMD-3 detectorCMD-3 is a general purpose detector designed to study $e^+e^-$ annihilation in hadrons in the wide energy range, $E_{c.m.s}=0.3\div2$~GeV. Since 2010 CMD-3 collected data at the $e^+e^-$ collider VEPP-2000 in the Budker Institute of Nuclear Physics. VEPP-2000 collider with $10^{32}cm^{-2}s^{-1}$ luminosity is the only present collider which covers its energy range. The calorimetry at the detector is based on three subsystems: closest to the beam pipe barrel Liquide Xenon calorimeter, outer barrel calorimeter based on CsI scintillation crystals and endcap calorimeter made of BGO scintillation crystals. We will describe the structure of the calorimeters along with its electronics. The energy calibration procedures with cosmic particles and using $e^+e^-$ scattering events will be described. The calorimeters characteristics will also be reported.Speaker: Mr Vasiliy Shebalin (Budker Institute of Nuclear Physics)
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A new-concept calorimeter for future neutrino beams based on Kaon taggingNeutrino cross section measurements are an essential requirement for the next generation of neutrino oscillation experiments and they are presently limited by uncertainties on neutrino fluxes. In [1] we propose to instrument a neutrino decay tunnel to detect large angle positrons and tag the three-body semileptonic $K^+ \to e^+ \pi^0 \nu_e$ decays. In such a facility the absolute electron neutrino flux could be determined with unprecedented precision (O(1\%)). An $e^+$/$\pi$ separation capability of about 2\% as well as a high $e^+$ efficiency is required for a diffuse particle source over a length of several tens of meters. Additional constraints, due to the harsh beam environment, involve radiation hardness and fast response. For this purpose we propose a specialised shashlik calorimeter (copper-scintillator) with a compact readout based on small-area Silicon PhotoMultipliers coupled to WLS fibers. The setup would allow an effective longitudinal segmentation for electron/hadron separation, reducing the dead zones introduced by fiber bundling. Detailed Monte Carlo simulations are in progress. The construction of a small prototype and exposures to pion and electron beams are foreseen. [1] A. Longhin, L. Ludovici and F. Terranova, "A novel technique for the measurement of the electron neutrino cross section", arXiv:1412.5987 [hep-ex], submitted to European Physical Journal C.Speaker: Andrea Longhin (LNF)
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A liquid hydrogen target for the calibration of the MEG and MEG-II liquid xenon calorimeterThe liquid xenon calorimeter of the MEG experiment at PSI is designed to have a percent-level resolution at a photon energy of $52.8~$MeV. To measure its performance, stability and uniformity it is mandatory to have a calibration source as close as possible to this energy. The charge exchange reaction of negative pions at rest on protons produces both mono-energetic 129~MeV photons and a flat spectrum from 55 to 83 MeV coming from the decay of the daughter neutral pions. With the aid of an opposite-side detector it is possible to tag almost monoenergetic 55~MeV photons impinging on the xenon detector. A fundamental device in this respect is the proton target to be placed at the center of the MEG experiment. Its design is non trivial since it has to be suspended at the center of a 3m long magnet, with a strong magnetic field and limited accessibility. We designed and operated a liquid hydrogen target that was used along the entire MEG data taking (2008-2013) to perform such a calibration. The hydrogen is liquefied by means of a continuous LHe flow in a 75cc cell made of stainless steel equipped with a thin mylar window to minimize the material along the $\pi^-$ trajectory. We describe, along with the obtained results on the detector resolution, its reliable and cost-effective design, its operation and the modifications needed to adapt the existing target for the calibrations of the liquid xenon calorimeter in the MEG-II upgrade (2015-2019).Speaker: Donato Nicolo' (PI)
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A high precision calorimeter for the CeSOX experimentThe Ce-SOX experiment is being built to clarify neutrino anomalies by observing possible short distance neutrino oscillations. For this purpose, a 100 kCi 144Ce-144Pr antineutrino generator will be placed under the BOREXINO detector at the Laboratori Nazionali del Gran Sasso in Italy. Thanks to its large size and very low background, BOREXINO is an ideal detector to discover or refute eV-scale sterile neutrinos. To reach the maximal sensitivity, we aim to determine the neutrino flux emitted by the antineutrino generator with a <1% accuracy. With this goal, INFN Genova and TU München are developing a vacuum calorimeter, which is designed to measure the source-generated heat released into a water coil, by measuring the flow and the temperature difference between the input and output lines with high accuracy. The system's design has been optimized to minimize heat losses, paying attention to conduction and infrared radiation, while keeping within the tight dimensional limits imposed by the available space. The entrance water temperature and flow stability will be strictly controlled to ensure the <1% activity measurement accuracy. The calorimeter is designed to meet the requirements of a possible second phase of the SOX experiment with a neutrino Cr-51 source (Cr-SOX). This presentation will discuss the present status including details on the embedded technologies, the stringent material selection aimed at satisfying the highest vacuum, thermal and safety requirements.Speaker: Mr Laszlo Papp (Physik-Department und Excellence Cluster Universe, Technische Universität München, Germany)
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Studies of an array of PbF2 Cherenkov crystals with large-area SiPM readoutThe electromagnetic calorimeter for the new muon (g-2) experiment at Fermilab will consist of arrays of PbF2 Cherenkov crystals read out by large-area silicon photo-multiplier (SiPM) sensors. We report here on measurements and simulations using 2.0 -- 4.5 GeV electrons with a 28-element prototype array. All data were obtained using fast waveform digitizers to accurately capture signal pulse shapes versus energy, impact position, angle, and crystal wrapping. The SiPMs were gain matched using a laser-based calibration system, which also provided a stabilization procedure that allowed gain correction to a level of 1e-4 per hour. After accounting for longitudinal fluctuation losses, those crystals wrapped in a white, diffusive wrapping exhibited an energy resolution sigma/E of (3.4 +- 0.1) % per sqrt(E/GeV), while those wrapped in a black, absorptive wrapping had (4.6 +- 0.3) % per sqrt(E/GeV). The white-wrapped crystals---having nearly twice the total light collection---display a generally wider and impact-position-dependent pulse shape owing to the dynamics of the light propagation, in comparison to the black-wrapped crystals, which have a narrower pulse shape that is insensitive to impact position.Speaker: Graziano Venanzoni (LNF)
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Response of a Close to Final Prototype for the Barrel of the PANDA Electromagnetic Calorimeter to Photons at Energies below 1 GeVThe PANDA detector at the future FAIR facility will be used to study proton - antiproton interaction. The electromagnetic calorimeter (EMC) of the target spectrometer with its expected excellent performance and efficiency for electromagnetic probes over a wide energy range from 10 MeV up to 15 GeV, will be one of the central components to achieve the physics goals. The barrel part of the EMC will consist of more than 11,000 lead tungstate (PWO-II) crystals operated at -25°C to achieve the required performance and efficiency. The most recent prototype PROTO120 represents a larger section of a barrel slice, containing the most tapered crystals and the close to final components. The readout is performed with two rectangular large area APDs per crystal, which are read out separately via the custom made APFEL-ASIC, adapted to the large dynamic range, with low power consumption and an optimized signal shaping. The present contribution will show the response of the PROTO120 to photons in the energy range between 50 MeV and 800 MeV. Furthermore, it will focus on the performance of the ASIC under real experimental conditions and on the analysis procedure including the signal extraction, noise rejection, calibration and the energy and position resolution using the information from both APDs. In addition, the position dependence of the energy resolution within the crystal and the implementation of higher order energy correction algorithms for improvement were studied.Speaker: Mr Christoph Rosenbaum (II. Physikalisches Instiut, University Gießen, Germany)
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Energy and time resolution for a LYSO matrix prototype of the Mu2e experimentA beam test of the prototype LYSO electromagnetic calorimeter for the Mu2e experiment at Fermilab has been performed at the beam test facility, BTF, of the Laboratori Nazionali di Frascati of INFN using electrons from 100 to 450 MeV. The time resolution of the 25 crystal matrix, readout by large area APD of Hamamatsu, has been measured with two techniques and compared with Monte Carlo simulations. A time resolution of $\sim$ 160 ps is obtained at 100 MeV. The first technique uses the timing of each single photosensor as derived by a fit to the signal pulses recorded with a 250 Msps Waveform Digitizer with respect to the timing provided by two scintillator counters. A second method uses instead the time difference between two neighbour cells thus allowing us also to estimate the timing resolution with the tagged photon beam of the MAMI (Mainz Microtron) facility.Speaker: Simona Giovannella (INFN - LNF)
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