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<font color=green >La Biodola, Isola d'Elba, Italy</color=green><!-- ID_UTENTE=804 -->
<font color=green >La Biodola, Isola d'Elba, Italy</color=green><!-- ID_UTENTE=804 -->
<a href=http://www.elba4star.it>Hotel Hermitage</a>
57037 La Biodola
Isola d'Elba (LI), Italy
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New Detector Systems and Upgrades: I
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ATLAS Detector OverviewThe ATLAS experiment was designed to explore a broad variety of phenomena that may arise in the high energies proton-proton collisions at the Large Hadron Collider (LHC). It was optimized for the search for the Higgs Boson in the largest possible mass range as well as for the search for heavy new particles such as those expected in supersymmetric models. The detector has been successfully taking data since first LHC collisions in Nov 2009. Over the last year the experiment collected data with an efficiency of close to 95% accumulating more than 5/fb of proton-proton data. In this period the luminosity dramatically increased, leading to a maximum of ~15 interactions per bunch crossing at the end of the 2011. During 2011 ATLAS also collected ~150/ub of data during the LHC lead-lead collision run. We present the status of the detector as well as the key aspects of the detector performance from the 2011 run. In addition we present prospects for the detector running in 2012 when the LHC will run with higher energy collisions and at higher luminosities.Speaker: Christoph Rembser (CERN)
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Performance and upgrade plans for the CMS detectorOver the last year the CMS experiment at the CERN Large Hadron Collider has been collecting data for an integrated luminosity exceeding 5 inverse femtobarn at 7 TeV center of mass energy. The detector has shown excellent performance, with very good data taking efficiency since the very beginning. The operational experience during 2011 data taking will be discussed, focusing on relevant technical aspects. Global CMS performance will be illustrated, including some examples taken from subdetectors performances. New challenges dictated by the luminosity increase are ahead of CMS in the future. A general overview of the upgrade plans to cope with new luminosity scenarios will be given, on both medium and long term range.Speaker: Marco Meschini (INFN - Firenze)
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10:50
coffee break
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Upgrade project and plans for the ATLAS detector and triggerIn the coming years different phases of upgrades for the LHC complex are foreseen, which will allow to extend the physics potential of its experiments. Through two different phases (namely phase-1 and phase-2), the average luminosity will be increased by a factor 5-10 above the design luminosity. Consequently, the detectors and the infrastructure of the DAQ system of the experiments will need to be upgraded as well, to take into account the increased radiation level and particle rates foreseen at such high luminosity. In this paper we describe the changes to the ATLAS detector and its trigger system, to face the increased number of interactions per collisions. This will cause higher level of pile-up and increased rates at each level of the trigger. The trigger detectors will improve their selectivity by benefiting from the increased granularity available at the trigger level, which will allow for a higher resolution. The use of the tracking system in the lower levels of the trigger selection is also discussed. It is foreseen that the second level trigger will be helped by a new Fast Tracking. The addition of tracking information at the first trigger level during the LHC upgrade phase-2 is currently under discussion. Different scenarios are compared, having in mind the requirements to achieve the expected physics potential of ATLAS in this high luminosity regime.Speaker: Ms Francesca Pastore (Royal Holloway University of London)
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Upgrade of the CMS Level-1 TriggerVarious parts of the CMS Level-1 hardware trigger will be upgraded to cope with increasing luminosity, using more selective trigger conditions at Level-1 and improving the reliability of the system. Many trigger subsystems use FPGAs (Field Programmable Gate Arrays) and will benefit from developments in this technology, allowing much more logic into a single FPGA chip, thus reducing the number of chips, electronic boards and interconnections and in this way improving reliability. A number of subsystems plan to switch from the old VME bus to the new microTCA crate standard. Using similar approaches, identical modules and common software whereever possible will reduce costs and manpower requirements and improve the serviceability of the whole trigger system.Speaker: Prof. Manfred Jeitler (HEPHY Vienna)
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Upgrade plans for the ATLAS CalorimetersThe ATLAS calorimeter is composed by detectors based on different techniques to exploit the best performance while maintaining a sufficient radiation resistance in each geometrical region. Radiation resistant liquid argon (LAr) sampling calorimeters are used for all electromagnetic sections, for the endcap (HEC) and forward (FCal) hadronic sections. The most central hadronic section is instead, a steel-scintillator sampling calorimeter. While LHC data-taking is expected to continue for a number of years, plans are already being developed for operation of the LHC and the detectors at an increased instantaneous luminosity about 5 times the original design value. There are plans for a two-phase detector upgrade. For phase-1, the LAr calorimeter trigger will be upgraded with new digital tower builder boards being designed to receive higher granularity signals, digitize them on the detector and send them via fast optical links to a new digital processing system. For phase-2 TileCal upgrade consists in replacing the on- and off-detector electronics so that all calorimeter signals are directly digitized and sent to the off-detector electronics in the counting room. Phase-2 upgrades being considered for the LAr system include changes to the DAQ, the HEC cold electronics and the FCal. Development work for these options includes high rate tests of small test modules of the endcap and forward detectors. Proposed solutions for LAr operations in phase-2 will be discussed.Speaker: Mr Frank Seifert (TU Dresden)
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Upgrade plans for CMS Calorimeters and Muon systemCalorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity (HL) Large Hadron Collider (LHC) Era demanding unprecedented options and R&D efforts necessary to upgrade the current LHC detectors and enabling discoveries. Several detector upgrades are foreseen for the Compact Muon Solenoid (CMS) detector currently operational at the LHC which is expected to have an ultimate luminosity of more than 10$^{34}$cm$^{−2}$s$^{−1}$ at 14 TeV targeted during Phase 1 (the first 10 year period of the accelerator) operation. In this paper, upgrade plans for Calorimetry and the Muon system will be discussed. Due to radiation damage to the active material of the Hadronic Endcap (HE) calorimeters, radiation hard quartz has been proposed. Photodiodes are being replaced by magnetic tolerant and with a better signal to noise ratio. For Electromagnetic Calorimetry (ECAL), the priority is to ensure stable and excellent performance throughout Phase 1 and to provide accurate predictions for performance in Phase 2 assuming no replacement of the ECAL. The muon Drift Tube (DT) system, performance, on the expectations of an adequate operation of the detector at higher luminosity, upgrades for Phase 1 are focused on improving the reliability of the system. The present Resistive Plate Chamber (RPC) detector, which serves as a dedicated muon triggering system, will be augmented with a fourth layer in the endcap region, along with CSC chambers on either side of the CMS detector; the details will be discussed.Speaker: Dr Archana SHARMA (CERN)
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New Detector Systems and Upgrades: II
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The TOTEM Experiment at the LHCThe forward physics experiment TOTEM at LHC (Interaction Point 5) is dedicated to measure the total and elastic p-p cross-section and to study diffractive processes. The TOTEM detector system is composed of 2 telescopes (T1, T2), and the Roman Pots, installed symmetrically on both sides of the IP 5. To cover the pseudo rapidity range from 3.1 to 4.7, the T1 detector is integrated in the CMS End Caps and centered at a distance of z=9 m with respect to the interaction point. Each side of the T1 telescope is partitioned in 5 planes, each consisting of 6 trapezoidal Cathode Strip Chambers (CSC). The T2 detector is made of 20 half circular sectors of Gas Electron Multipliers (GEM), which are installed at an average distance of z=13.5 m from the interaction point, between the vacuum chamber and the inner shielding of the CMS HF calorimeter,covering the rapidity range from 5.3 to 6.5. At distances of +/- 147 m and +/- 220 m with respect to the IP5 interaction point, the Roman Pot detectors are integrated in the LHC as movable beam insertions, approaching the LHC beam centre to an ultra close distance of less than 7 sigma. Protons, scattered at the interaction point under smallest angles down to 200 microradians, are registered with the 24 RPs,each equipped with 10 planes of edgeless Si strip detectors. The edgeless detectors are characterized by an active area close to 50 um from the Si cutting edge. The contribution describes the status of the TOTEM experiment and it's performance.Speaker: Dr Joachim Baechler (CERN)
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Performance and Upgrade Plans of the LHCb Trigger SystemThe LHCb High Level Trigger (HLT) is implemented in a farm of parallel-processing CPUs, and serves to reduce the event rate from an input of 1 MHz to an output rate of around 2 kHz, with a processing time of around 20 ms per event. In order to maximize efficiencies and minimize biases, the trigger is designed around highly inclusive selection algorithms, culminating in a novel boosted decision tree which enables the efficient selection of heavy flavour deca ys based on a robust partial reconstruction of their decay products. The major bottleneck in LHCb's trigger efficiencies is the hardware trigger which reduces the event rate to the 1MHz detector readout speed. In order to improve performance, the LHCb upgrade aims to significantly increase the speed at which the detector will be read out. As a consequence, the HLT will have to process more than 10MHz of events. We demonstrate that the current HLT architecture will be able to meet this challenge, particularly in the context of running stability and long term reproducibility of the HLT decisions which are crucial to the programme of precision physics measurements for which the LHCb upgrade is being built. We also discuss the expected efficiencies and signal yields per unit luminosity in several key channels for the LHCb upgrade.Speaker: Vava Gligorov (CERN)
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Performance and future plans of the ALICE experimentThe ALICE Experiment at the LHC is providing precision measurements on strongly interacting matter at unprecedented high-energy density by studying A-A, p-A and pp collisions. This will allow a detailed characterization of the properties of the Quark-Gluon Plasma in the first running period up to 2017. Further progress in understanding the dynamics of this condensed phase of QCD will need to focus on rare probes and the study of their collective properties and hadronization mechanism, particularly at soft momentum scales. Such considerations have motivated the development of a comprehensive upgrade strategy for ALICE to provide high rate capability (50 kHz for Pb-Pb collisions), in a near minimum bias mode, and improved tracking accuracy at low momentum. This talk will cover the experimental challenges and performance of the ALICE current detector and give an overview of the upgrade program, including a discussion of the modifications and replacements needed in all ALICE detectors and online systems for high luminosity running.Speaker: Vito Manzari (BA)
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The LHCb VELO UpgradeThe upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a triggerless system operating at 40 MHz. All data reduction algorithms will be executed in a high level software farm, with access to all event information. This will enable the detector to run at luminosities of above $2\times10^{33} \mathrm{cm}^{-2}\mathrm{s}^{-1}$ and explore New Physics effects in the beauty and charm sector with unprecedented precision. The vertex detector will have to cope with radiation levels of up to $10^{16}$ 1-MeV neutron equivalents / cm$^2$, more than an order of magnitude higher than those expected at the current experiment. A solution is under development for a hybrid pixel detector based on $55 \times 55 \mu\mathrm{m}^2$pixels. A dedicated ASIC development is underway for a new FE chip, dubbed VELOPix, from the Timepix/Medipix family of chips. The chip will be radiation hard and be able to cope with pixel hit rates of above 500 MHz, highly non-uniformly distributed over the ~2 cm$^2$ chip area. It will incorporate local intelligence in the pixels for time-over-threshold measurements, time-stamping and sparse readout. The material budget will be optimised with the use of novel heat dissipation techniques and sensor and ROC thinning. In addition a micro-strip solution is as also under development, with finer pitch, higher granularity and lower mass than the current detector. The current status will be described together with a presentation of recent testbeam results.Speaker: Heinrich Schindler (CERN)
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16:10
coffee break
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The ALICE Silicon Tracker UpgradeThe long-term physics program of the ALICE experiment at the CERN LHC relies on a major upgrade of the central barrel detectors planned for the second long LHC shutdown (LS2) that as of today is scheduled for 2017/18. A key aspect of the global upgrade strategy is to develop the capability to collect Pb-Pb data at an interaction rate up to 50 kHz, with the least possible bias, and improved performance in terms of secondary vertex reconstruction. The upgrade of the existing silicon Inner Tracking System (ITS) is a fundamental cornerstone of this upgrade plan, which will allow to access new measurements on the charm and beauty production. The baseline idea is to build an entirely new ALICE Silicon Tracker (AST) to replace the existing ITS. The AST will be based on 7 silicon layers: three inner layers of pixel detectors followed by four outer layers of pixel or double-sided microstrip detectors. This contribution will present the on going studies and developments of the AST. The layout options and the technical features that are being evaluated for the AST will be described. The effects of the radial position, material budget and segmentation of the layers on the performance of the AST in terms of impact parameter resolution, standalone tracking efficiency, momentum resolution and readout rate capabilities will be discussed.Speaker: Dr Petra Riedler (CERN)
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Overview of the ATLAS Insertable B-Layer (IBL) ProjectThe upgrades for the ATLAS Pixel Detector will be staged in preparation for high luminosity LHC. The first upgrade for the Pixel Detector will be the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine, foreseen in 2013-14. The new detector, called the Insertable B-layer (IBL), will be installed between the existing Pixel Detector and a new, smaller radius beam-pipe at a radius of 3.3 cm. The IBL will require the development of several new technologies to cope with increased radiation and pixel occupancy and also to improve the physics performance through reduction of the pixel size and a more stringent material budget. Two different and promising silicon sensor technologies, planar n-in-n and 3D, are currently under investigation for the IBL. An overview of the IBL project, of the module design and the qualification for these sensor technologies with particular emphasis on irradiation and beam tests will be presented.Speaker: Dr Didier Ferrere (Université de Genève)
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The upgrades of the CMS tracker: status and plansLHC is expected to increase its luminosity above the original nominal value of $1\times10^{34}\,\mathrm{cm}^{−2}\mathrm{s}^{−1}$, eventually achieving an order of magnitude increase after major upgrades will be performed after 2020. This configuration of the machine is known as High Luminosity-LHC (HL-LHC). CMS plans two upgrades of the tracking system. In the second half of this decade the present pixel system will be replaced. This replacement is called the Phase-1 upgrade and aims to improve the performance up to peak luminosities of $3\times10^{34}\,\mathrm{cm}^{−2}\mathrm{s}^{−1}$. The new features are ultra-light mechanical design with four-barrel layers and three end-cap disks, a novel two-phase cooling system and a digital readout chip with higher rate capabilities. In the next decade the CMS experiment will need a completely new tracking system (called the Phase-2 upgrade) to maintain adequate performance in the HL-LHC environment and to provide tracking information for the Level-1 trigger decision. Innovative solutions are being studied to improve tracking resolution, reduce the material budget, increase the sensor granularity and provide useful information for an upgraded trigger system. The new detector will also have to fit within the constraints of the present allocated services and volumes, thus a special care is needed in managing the power budget and the available I/O bandwidth. The presentation will cover both upgrades with emphasis on prototypes and production plans for Phase-1 while for the Phase-2 system the focus will be on the most relevant requirements and constraints, along with highlights from the R&D activities.Speaker: Dr Gino Bolla (Purdue University)
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The silicon Micro Vertex Detector of the PANDA experimentThe PANDA experiment will make use of cooled antiproton beams of unprecedented quality, that will become available at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, featuring up to $2\times10^{11}$ antiprotons and momentum between 1.5 – 15 GeV/c. The physics program includes measurements of hyperons produced at low energies, spectroscopy of the charmonium and open-charm mesons. To handle the forward particle distribution due to the Lorentz boost, the apparatus is arranged in an asymmetric layout around the interaction point between antiprotons and pellet or gas jet target. This peculiarity requires a tracking detector with a forward design and in particular an innermost Micro Vertex Detector based on silicon devices with an unusual geometry. The material budget of this silicon tracker has to be minimized in view of particle momenta ranging from few hundreds of MeV/c up to several GeV/c. Besides, the high interaction rate asks for fast data readout as PANDA is without low-level trigger selection and particle identification is planned over the full range of energies. The status of the MVD will be presented.Speaker: Dr Daniela Calvo (INFN - Torino)
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Stategies - Round Table
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Prospects from CERNSpeaker: Sergio Bertolucci (LNF)
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Prospects from GermanySpeaker: Prof. Joachim Mnich (DESY)
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Prospects from INFNSpeaker: Fernando Ferroni (ROMA1)
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10:45
coffee break
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Calorimetry
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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 the performance of a matrix of molybdenum doped lead tungstate crystals specifically built for this purpose, new data on the application of the polarization of Cherenkov light in this context, and the first test results of prototype modules for the new full-scale DREAM fiber calorimeter.Speaker: Prof. Richard Wigmans (Texas Tech University)
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Timing Resolution Measurements of a 3'' Lanthanum Bromide DetectorCerium-doped lanthanum bromide (LaBr:Ce) is a scintillator that present very good energy and timing resolution. Its light yield is 1.5 times that of sodium iodide, yet its time constant is much shorter (20 ns). These properties, toghether with its high density and the presence of a 2.5 MeV self-activity line, make it a perfect candidate for a self-calibrating photon detector in the 50-100 MeV energy range as, for instance, in future experiments to search for lepton flavour violation as in µ→eγ or µ→e conversion. In the former a monochromatic 52.8 MeV γ-ray must be discriminated from a continuous background, while in the latter the signature is given by a monoenergetic positron of about 100 MeV. While energy relolution was thoroughly investigated, timing resolution at several MeV presents some experimental challenge. We measured the timing resolution of a 3'' x 3'' cylindrical BrLaCe crystal against a YAP detector read by an Hamamatsu fine mesh PMT by means of a nuclear reaction from a Cockcroft-Walton accelerator that produces coincident gamma rays in the 4.4 to 16 MeV range. Preliminary results allow us to extrapolate the properties of a segmented gamma ray detector in the 50-100 MeV range.Speaker: Luca Galli (INFN - Pisa)
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BiPo: A Dedicated Radiopurity Detector for the SuperNEMO ExperimentNew generation experiments in Astroparticle Physics need to operate in really restrictive background conditions, which implies the use of high radiopure materials for the experimental setup construction. For this reason the screening of the materials with enough sensitivity has become a challenge that sometimes cannot be afforded with standard techniques like Germanium detector spectroscopy. BiPo is a dedicated detector, that will operate in the Canfranc Underground Laboratory, designed to measure the radiopurity, mainly of the bb sources of the SuperNEMO experiment, by the detection of BiPo events. But also has been recently considered to measure other elements of the SuperNEMO experimental setup. It is composed of two modules with 40 optical lines each that register the energy and the time of the emitted particles. The well known features of the BiPo events (delayed coincidence between an electron and an alpha particle) facilitate the discrimination of other background events that could entangle the expected signal. In addition, the geometry of the detector, with an active area of around 3.6 m$^2$, has been optimized to reach the necessary sensitivity levels for the SuperNEMO source foils in the shortest time possible. Main features of the detector, present status and prospects and its crucial role inside the SuperNEMO schedule will be presented in this talk.Speaker: Dr Hector Gomez (LAL-Orsay)
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The Calorimeter Project for the Mu2e Experiment.The Mu2e experiment at FNAL aims to measure the charged-lepton flavor violating neutrinoless conversion of of a negative muon into an electron. The conversion results in a monochromatic electron with an energy slightly below the rest mass of the muon (104.97 MeV). The calorimeter should confirm that the candidates reconstructed by the extremely precise tracker system are indeed conversion electrons. We therefore look for a calorimeter with a large acceptance, excellent energy resolution O(2%) and a reasonable position (time) resolution of few mm (<1 ns). Moreover, the calorimeter should also provide a trigger for the experiment and perform a powerful mu/e particle identification. Finally, it should be able to keep functionality in an environment where the background delivers a dose of ~ 200 Gy/year in the hottest area. It will also need to work immersed in 1 T axial magnetic field. The baseline version of the Mu2e calorimeter is composed of four homogeneous parallelepiped vanes with ~ 2000 rectangular LYSO crystals, 3x3x11 cm$^3$ dimension, each read out by two large area APDs. photodiodes (APD's). We show the calorimeter design, the results obtained at 100 MeV with a small size prototype and the excellent data-to-MC comparison for these data. We also show the simulation of the calorimeter in mu2e and the plans for R&D and calibration.Speaker: Alessandra Luca (INFN - LNF)
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Calorimetry - Poster Session
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A LYSO Calorimeter for the SuperB factoryThe SuperB project is an asymmetric e+e− accelerator of $10^{36}cm^{−2}s^{−1}$ luminosity, capable of collecting a data sample of 50–75 ab$^{−1}$ in five years of running. The SuperB electromagnetic calorimeter (EMC) provides energy and direction measurement of photons and electrons, and is used for identification of electrons versus other charged particles. In particular we will present its design, geometry study and related simulations, as well as R&D on LYSO crystals and development on readout and electronics. A matrix of 25 crystals has been tested at the PS beam test facility at CERN in October 2010 at energies between 1 GeV and 3 GeV and at the Beam Test Facility of Frascati (BTF) in May 2011 at energies between 200 MeV and 500 MeV. Results from these tests will be presented.Speaker: Dr Alessandro Rossi (INFN - Perugia)
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A Pb-SciFi Calorimeter for the Small Angle Interaction Region of BESIII at BEPCIIA minicalorimeter has been built in the Frascati National Laboratory (LNF) of INFN for the BESIII detector, based at the BEPCII storage rings of the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences. It has been installed in one of the two small-theta angle regions of BESIII to measure the energy of photons from Initial State Radiation (ISR) events with an expected resolution of approximately $10\%/\sqrt E \, (GeV)$. The technique used is the sandwich of Pb and scintillating fibers employed for the KLOE calorimeter at the DAFNE accelerator at LNF, but the readout is actuated by way of bundles of clear plastic fibers. We present here fabrication details as well as results from tests in cosmic rays and at the Frascati Beam Test facility (BTF). We also show its installation in the experimental area and some very early results from data taken during e+ e- collisions.Speaker: Adriano Zallo (LNF)
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Calibration and Monitoring systems for the ATLAS Tile Hadron CalorimeterThe TileCal is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. It is a sampling calorimeter with iron plates as absorber and plastic scintillating tiles as the active material. The scintillation light produced by the passage of charged particles is transmitted by wavelength shifting fibers to about 10000 photomultiplier tubes (PMTs). Integrated on the calorimeter there is a composite device that allows to monitor and/or equalize the signals at various stages of its formation. This device is based on signal generation from different sources: radioactive, LASER and charge injection and minimum bias events produces in proton-proton collisions. In this contribution is given a brief description of the different systems hardware and presented the latest results on their performance, like the determination of the conversion factors, timing adjustment, linearity and stability. Foreseen improvements will be shown.Speaker: Dr Djamel Boumediene (LPC Clermont CNRS / IN2P3 Univ. Blaise Pascal)
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Calibration of the CMS Electromagnetic Calorimeter with LHC collision dataThe CMS ECAL is one of the highest resolution electromagnetic calorimeters ever constructed, but relies upon precision calibration in order to achieve and maintain its design performance. Variations in light collected from the lead tungstate crystals, due to intrinsic differences in crystals/photodetectors, as well as variations with time due to radiation damage for example, need to be taken into account. Sophisticated and effective methods of inter-crystal and absolute calibration have been devised, using collision data from the 2011 LHC run and a dedicated light injection system. For inter-calibration, low mass particle decays (pi0 and eta) to two photons are exploited, as well as the azimuthal symmetry of the average energy deposition at a given pseudorapidity. Absolute calibration has been performed using Z0 decays into electron-positron pairs. The light injection system monitors the transparency of the crystals in real-time and enables the re-calibration of the measured energies over time. This is cross-checked by the comparison of E/p measurements of electrons from W decays (where the momentum is measured in the CMS tracker) with/without these re-calibrations applied. The calibration procedures will be discussed in detail and we show the results obtained from the entire 2011 dataset.Speaker: Dr Maria Margherita Obertino (Universita' del Piemonte Orientale)
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CCALT: a Crystal Calorimeter for the KLOE-2 ExperimentIn the new design of the DAFNE interaction region, the position of the inner quadrupoles leaves place for inserting a crystal calorimeter to tag low energy photons in the angular region between 10 and 18 degrees thus increasing the acceptance of the central calorimeter for rare eta and kaon decays ( such as $K_s \rightarrow \gamma \gamma$, $\eta \rightarrow \pi^0 \gamma \gamma$, $K_s \rightarrow 3 \pi^0 $ ...) The proposed solution is to insert an homogeneous calorimeter immersed in a 0.52 kG axial magnetic field, CCALT, based on the new generation of crystals, LYSO, characterized by a very high light yield (60% of NaI), 40 ns emission time, high density and radiation length. These crystals match the request for a high efficiency for low energy photons and an excellent time resolution needed by the calorimeter to sustain the high level of machine background events. In order to maximize the light collection and improve its timing performance we have tested its response both with the fastest Hamamatsu APD than with large area SIPMs from FBK-IRST. We have built a prototype matrix of 9 2x2x13 cm$^3$ LYSO crystals read-out by 10x10 mm$^2$ Hamamatsu avalanche photodiodes (APD) surrounded by 12 PBWO for outer leakage recovery (3 Moliere radius in total) read-out by bialkali photomultipliers. We have tested it using cosmic rays, and at electron ( beam test facility of Frascati,2010) and photon beams (MAMI accelerator facility at Mainz, 2011). The measurements carried on ad the BTF in Frascati resulted in a very goSpeaker: Dr Simona Giovannella (INFN - LNF)
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CMS Electromagnetic Calorimeter Performance During the 2011 LHC RunThe CMS Electromagnetic Calorimeter (ECAL) is a high resolution, fine-grained calorimeter devised to measure photons and electrons at the LHC. Built of lead tungstate crystals, it plays a crucial role in the search for new physics as well as in precision measurements of the Standard Model. A preshower detector, based on silicon strip sensors, improves position measurements and particle identification in the endcaps. The operation and performance of the ECAL during the 2011 run at the LHC, with pp collisions at $\sqrt s = 7\, TeV$ will be reviewed. Pure samples of electrons and photons from decays of known resonances have been exploited to improve and verify the trigger efficiency, the reconstruction algorithms, the detector calibration and stability, and the particle identification efficiency. A review of all these aspects will be given.Speaker: Jean-Louis Faure (DSM/IRFU-Saclay)
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Construction of Semi-Digital Hadronic CALorimeter for future ILC experimentsA high-granularity semi-digital Hadronic calorimeter using GRPC as sensitive medium is to be proposed for the future International Linear Collider project. A prototype of 1 m$^3$ was built within the CALICE collaboration in order to validate this option. The prototype intends to be as close as possible to the one proposed in the ILD Letter Of Intent. The active media of this HCAL are large GRPC detectors equipped with semi-digital electronics readout and 1 cm$^2$ lateral granularity. The GRPC detector was designed to provide high detection efficiency, excellent homogeneity and negligible dead zones. The readout electronics was developed to associate performance and compactness. 48 GRPCs with their embedded electronics were tested in cosmic rays bench before to be assembeled into the HCAL prototype. The HCAL was then tested with pion beams at CERN. The preliminary results confirm the expectations. Future tests at the CERN PS nd SPS will allow to validate definitely the choice of the GRPC as a good candidate for the sensitive medium of a semi-digital hadronic calorimeter.Speaker: Mrs Sameh Mannai (Université Catholique de Louvain, Belgique)
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Dependence of the Energy Resolution of a Scintillating Crystal on the Read-Out Integration time.When using detectors made of a crystal and a photo-detector in high rate applications it is not always possible to integrate the whole signal, the integration time being dictated by the need to avoid in the read-out the pile-up due to the large background of low energy particles. By means of both experimental data on a BGO crystals and simulation, we developed a technique to compute the fraction of the emitted photo-electrons that participate to the formation of the signal up to its maximum ($F_{int}$). We demonstrate that when the number of photo-electrons is large the energy resolution scales as $1/\sqrt{F_{int}}$. We also show that when the number of photo-electrons is small the resolution is even better than the Poisson fluctuations. Finally we detail the case of BGO. It is considered as an option for the forward calorimeter of the SuperB experiment and it would, in this case, need to be read with an integration time as small as 100 ns, i.e. one third of the decay time of its scintillation. Our measurements demonstrate that in this configuration the loss of energy resolution is absolutely tolerable and that therefore BGO is an attractive possibility for equipping calorimeters also in very high rate experiments.Speaker: Davide Pinci (ROMA1)
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Detection of Electron Showers in Dual-Readout Crystal CalorimetersFirst attempts to use electromagnetic calorimeter prototypes made of Mo-doped PbWO4 crystals or by BGO crystals, in view of the possible application of such a detector in dual-readout hybrid calorimetry will be presented. We have tested matrices of these crystals as electromagnetic calorimeters and studied the properties of the Cerenkov and scintillation components of the signals generated by high-energy electrons showering in these detectors. Dual-Readout calorimetry (DREAM) was proposed as a technique that would make it possible to eliminate the factors that traditionally limit and spoil the performance of the large hadron calorimeters operating in modern particle physics experiments at the energy frontier. By comparing the signals generated in the form of Cerenkov and scintillation light, it is possible to determine the electromagnetic shower fraction for individual events, and its fluctuations, which are the dominant contribution to the hadronic energy resolution, can be eliminated. In recent years, the RD52 collaboration have developed four different methods to split crystal signals into their scintillation and Cerenkov components. These methods exploit differences in the angular distribution of the light, in the spectral characteristics, in the time structure of the signals, and the fact that Cerenkov light is polarized. In this poster we investigate to what extent the promise of improved calorimeter performance can be realized with such crystals.Speaker: Michele Cascella (Università del Salento e INFN di Lecce)
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Determination of the Jet Energy Scale Uncertainty in ATLASAbout one year after the first proton proton collisions at a centre of mass energy of $\sqrt{s}= 7$TeV the ATLAS experiment has achieved an accuracy of the jet energy measurement between 2-4% for jet transverse momenta from 20 GeV to 2 TeV in the pseudo-rapidity region up to eta=4.5. The jet energy scale uncertainty is derived from in-situ single hadron response measurement a long with systematic variations in the Monte Carlo simulation. In addition, the transverse momentum balance between a central and a forward jet in events with only two jets at high transverse momentum is exploited. The obtained uncertainty is confirmed by direct in-situ measurements exploiting the transverse momentum balance between a jet and a well measured reference like the photon transverse in photon-jet events or the total transverse track momentum. Jets in the TeV-energy regime can be also tested using a system of well calibrated jets at low transverse momenta against a high-pt jet. Results obtained from 2010 and 2011 will be presented.Speaker: Ms Lucy Kogan (Oxford University)
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Mu2e: A New High-Sensitivity Muon-Electron Conversion Search at FermilabMu2e will search for coherent, neutrino-less conversion of muons into electrons in the field of a nucleus to a few parts in $10^{-17}$, a sensitivity improvement of a factor of 10,000 over existing limits. Muon-Electron conversion provides unique windows into new physics inaccessible to other lepton flavor violation searches and probes up to mass scales ~ $10^4$ TeV, far beyond the reach of present or planned high energy colliders. We present the design of the muon beamline and spectrometer, how the experiment fits in the current Fermilab complex, and discuss potential upgrades at Fermilab's Project X.Speaker: Dr Giovanni Onorato (Universita' Guglielmo Marconi / Fermilab)
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New Photosensors for the CMS Hadronic Calorimeter 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 detected by photo-sensors. The photo-sensors that are currently used are hybrid photodiodes (HPDs).The HCAL upgrade is required for the increased luminosity ($5\times10^{34}$) of SLHC. A key aspect of the HCAL upgrade is to add longitudinal segmentation to improve background rejection, energy resolution, and electron isolation at L1 trigger. The increased segmentation can be achieved by replacing the hybrid photodiodes (HPDs) with multi-pixel Geiger-mode avalanche photodiodes (also known as silicon photomultipliers (SiPMs)). The SiPMs for the CMS HCAL upgrade have to operate in a very hostile SLHC radiation environment. They should have good linearity for a wide range of scintillating signals and excellent reliability. Here we report on our studies of the most recent large dynamic range (2500 - 15000 cells/mm$^2$) SiPMs developed by Hamamatsu (Japan), Zecotek (Singapore), KETEK (Germany) and NDL (China) for the CMS HCAL Upgrade project. The results of our measurements of photon detection efficiency, spectral response, cell recovery time, linearity for fast LED and Y11 WLS light, as well as the results on the radiation hardness of SiPMs will be reported in this presentation.Speaker: Dr Jacob Anderson (Fermilab)
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Operational Experience with the CMS CASTOR Calorimeter at the LHCCASTOR is a Cerenkov quartz-tungsten sampling calorimeter, installed in the very forward region of the CMS experiment at the LHC and covering the pseudorapidity range of −5.2 to −6.6. The calorimeter surrounds the beam pipe as a very compact structure of tungsten and quartz plates, with a depth of 10 interaction lengths. The granularity of 16 azimuthal sectors and 14 longitudinal sections (rings), 224 channels in total, allows for the reconstruction of shower profiles and the separation of the electromagnetic from the hadronic energy. The very forward location of CASTOR and geometry of the shielding imply operation under high radiation dose and magnetic field. Except for some very particular regions, the calorimeter read-out with fine mesh PMTs demonstrates good performance under these tough conditions. The performance of the calorimeter and first operational experience in pp and HI collisions in the very forward region of CMS will be presented.Speaker: Prof. Apostolos Panagiotou (University of Athens)
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Performances of the Signal Reconstruction in the ATLAS Hadronic Tile CalorimeterThe Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of ATLAS. It is a key detector for the reconstruction of hadrons, jets, taus and missing transverse energy. TileCal is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25 ns. The read-out system is designed to reconstruct the data in real time fulfilling the tight time constraint imposed by the ATLAS first level trigger rate (100 kHz). The signal amplitude for each channel and the phases are measured using Optimal Filtering techniques both at on-line and off-line level. We present the performances of these techniques on the data collected in the proton-proton collisions at center-of-mass energy equal to 7 TeV. We show in particular the measurements of low amplitudes, where the cell signals and the noise overlap, using as probe high transverse momenta muons produced in the proton-proton collisions.Speaker: Dr Evelin Meoni (IFAE - Barcelona)
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Progress on the Upgrade of the CMS Hadron Calorimeter Front-End ElectronicsWe present a scheme to upgrade the CMS HCAL front-end electronics in the second long LHC shutdown (~2017). The HCAL upgrade is required to handle a major luminosity increase of the LHC that is expected for 2017. A key aspect of the HCAL upgrade is to readout longitudinal segmentation information to improve background rejection, energy resolution, and electron isolation at the L1 trigger. This paper focuses on the requirements for the new electronics and on the proposed solutions. The requirements include increased channel count, additional timing capabilities, and additional redundancy. The electronics are required to operate in a harsh environment and are constrained by the existing infrastructure. The proposed solutions span from chip level to system level. They include the development of a new ADC ASIC, the design and testing of higher speed transmitters to handle the increased data volume, the evaluation and use of circuits from other developments, evaluation of commercial FPGAs, better thermal design and improvements in the overall architecture.Speaker: Dr Jacob Anderson (Fermilab)
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QCALT: A tile Calorimeter for KLOE-2 UpgradeThe upgrade of the DAFNE machine layout requires a modification of the size and position of the inner focusing quadrupoles of KLOE-2 thus asking for the realization of two new calorimeters covering the quadrupoles area. To improve the reconstruction of $K_L \rightarrow 2 \pi^0$ events with photons hitting the quadrupoles a calorimeter with high efficiency to low energy photons (20-300 MeV), time resolution below 1 ns and space resolution of few cm, is needed. To match these requirements, we are realizing two tile calorimeters, QCALT, one for each side of IP, where each detector has a dodecagonal structures, made by a sampling of scintillator tiles and tungsten, for a total thickness of 5X$_0$. Each tile is covered with refractive paint and grooved to insert 1 mm round multicladding WLS fibers. Each fiber is readout with 1.2 mm custom round SiPM bonded on alluminum PCB. During R&D phase we have developed custom silicon photosensors and a novely soldering and resining technique. This ensures the required mechanical precision in the coupling between fibers and SiPM. The two QCALTs have a total of around 2000 channels. The PCB of SIPMs is then connected to FEE cards which provide bias supply, amplification and discrimination of SiPM signals. The HV supply has a precision of 0.1% and stability at 0.01% level. The preamplifier ensure signal stability along time and no deterioration during transport. The construction of QCALT is actually in progress with its construction foreseen for June 2012.Speaker: Dr Alessandro Saputi (LNF)
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Shashyk EM Calorimeter Prototype Readout by MAPD with Superhigh Pixel Density for COMPASS IIThe design of the new of Shashyk EM calorimeter ECAL0 for COMPASS II (CERN) is described. Micropixel avalanche photodiodes MAPD-3N with the density of pixels 15000 per square mm and area 3×3 mm manufactured by the Zecotek Company are used as photodetectors. Preliminary results of studying the energy resolution of the ECAL0 3×3 module matrix at the T9 CERN PS test-beam facility are presented.Speaker: Dr Igor Chirikov-Zorin (JINR)Poster
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Shower Development in a Highly Granular Scintillator-Tungsten HCAL of Particles with Momenta below 10 GeVWe present the study of the showers initiated by low momentum (p <10 GeV) electrons, pions and protons in the highly granular CALICE scintillator-tungsten HCAL. The data were taken at the CERN PS in 2010. The analysis includes energy resolution measurements for each particle type and studies of the shower development in both longitudinal and transverse planes. The results are compared with several GEANT4 modelsSpeaker: Angela Lucaci Timoce (CERN)
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Shower Library Technique for Fast Simulation of Showers in Calorimeters of the H1 ExperimentFast simulation of showers in calorimeters is very important for particle physics analysis since shower simulation typically takes significant amount of the simulation time. At the same time, a simulation must reproduce experimental data in the best possible way. In this paper, a fast simulation of showers in two calorimeters of the H1 experiment is presented. High speed and good quality of shower simulation is achieved by using a shower library technique in which the detector response is simulated using a collection of stored showers for different particle types and topologies. The library is created using the GEANT programme. The fast simulation based on shower library is compared to the data collected by the H1 experiment.Speaker: Dr Natasa Raicevic (University of Montenegro)
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Silicon Photomultipliers as Readout System for Shashlik and Crystal Based CalorimetersSilicon PhotoMultipliers (SiPMs) consist of a matrix of small passively quenched silicon avalanche photodiodes operated in limited Geiger-mode (GM-APDs) and read out in parallel from a common output node. Each pixel (with a typical size in the 20-100 $\mu$m range) gives the same current response when hit by a photon; the SiPM output signal is the sum of the signals of all the pixels, which depends on the light intensity. The main advantages of SiPMs with respect to the photomultiplier tubes (PMTs) are essentially the small dimensions, the insensitivity to magnetic fields and a low bias voltage. This contribution presents the performance of a SiPM based readout system for shashlik and crystal calorimeters developed in the framework of the FACTOR/TWICE collaboration. A prototype of shashlik calorimeter has been tested with an array of 36 (6400 cells each) SiPMs using low and high energy electrons. The SiPMs have been readout using a frontend board based on the MAROC3 ASIC, while a LED system has been used to monitor and correct the gain variations due to the temperature drift. On the other hand, a new type of SiPM, consisting in a matrix of four sensors embedded in the same silicon substrate (called QUAD) has been tested coupled to a lead tungstate crystal, an early-prototype version of the crystals developed for the electromagnetic calorimeter of the CMS experiment. New tests are foreseen using a complete module consisting of nine crystals, each one readout by two QUADs.Speaker: Dr Alessandro Berra (MIB)
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Single Hadron Response Measurements in ATLASSingle hadron response measurement in minimum bias proton-proton collisions at a center of mass energy of $\sqrt s = 7 \, TeV$ are presented. Together with test-beam results these measurement form the basis to evaluate the calorimeter response uncertainty of jets at high transverse momenta. The novel technique to evaluate the jet from the single particle response will be presented. The single hadrons response is measured in the momentum range of 0.5 to about 20 GeV in-situ by comparing the calorimeter response of all energy deposits in a cone around an isolated track with the precisely measured track momenta. The agreement between data and Monte Carlo simulation is on the level of a few percent. Using kaon and Lambda particles the calorimeter response of identified pions, proton and anti-proton The MC simulation describes pions and protons well, but differences are observed for anti-protons. It is discuss how the jet calorimeter response uncertainty and it correlation between tranverse momentum bins is determined from these measurements.Speaker: Mr Mário Sousa (LIP-Lisbon, FCUL)
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Status of the Atlas Liquid Argon Calorimeter and its Performance after Two Years of LHC OperationThe ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LHC beams. Since then, around 5 fb$^{-1}$ of data have been collected at a center of mass energy of 7 TeV. During all these stages, the calorimeter and its electronics have been operating almost optimally, with performances very close to the specification ones. The talk will cover all aspects of these first years of operation, including the calibration efforts, the data quality assessment procedure, and the final performance.Speaker: Mrs Ludovica Aperio Bella (LAPP)
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The ATLAS Tile Calorimeter Performance at LHCThe Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. Due to the very good muon signal to noise ratio it assists the spectrometer in the identification and reconstruction of muons. TileCal is built of steel and scintillating tiles coupled to optical fibers and read out by photomultipliers. The calorimeter is equipped with systems that allow to monitor and to calibrate each stage of the read-out system exploiting different signal sources: laser light, charge injection and a radioactive source. The performance of the calorimeter has been measured and monitored using calibration data, random triggered data, cosmic muons, splash events and most importantly the large sample of pp collision events acquired in 2011. Results on the absolute energy scale calibration precision, on the energy and timing uniformity and on the synchronization precision are presented. These results demonstrate that the Tile Calorimeter is performing well within the design requirements and is giving essential input to the physics results.Speaker: Ms Yesenia Hernandez (University of Valencia)
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The FOXFIRE Liquid Xenon Detector R&D ProjectThe FOXFIRE R&D project (FIRB On a Xenon detector with Frontend for Ionization Real-time Extraction) aims at studying and developing new techniques for the detection of rare processes in elementary particle physics by means of condensed noble gases detectors. Noble liquids, notably liquid xenon, present in fact a unique set of characteristics (high density and stopping power, high light yield) which makes them an ideal choice as a detector active material. Particles in noble liquids release energy in the form of both scintillation light and electron-ion pair formation. Many research groups investigated the combination of charge and light information for improved energy resolution and particle discrimination in the low-energy (from ten keV up to ~ MeV), low-rate regime, ideal for measuring rare processes such as neutrino-less double-beta decay or weakly interacting dark matter interactions. We are studying the extension of these techniques towards high-rate, high-energy (tens of MeV) environments with particular emphasis on real-time event reconstruction. This requires facing new problems from the point of view of both mechanical design and electronic signal handling. Preliminary studies on simultaneous readout of scintillation light and ionization charge with a liquid xenon detector prototype built at INFN Pisa will be presented together with future developments.Speaker: Dr Giovanni Signorelli (INFN Pisa)
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Tracking and Calorimeter Performance for Tau Reconstruction at ATLASTau leptons will play an important role in the physics program at the LHC. They will be used not only in searches for new phenomena like the Higgs boson or Supersymmetry and electroweak measurements but also in detector related studies like the determination of the missing transverse energy scale. Optimal identification of hadronically decaying tau leptons is achieved by using detailed information from tracking and calorimeter detector components. Variables describing the properties of calorimeter energy deposits and track reconstruction within tau candidates are combined in multi-variate discriminants, to achieve high rejection against backgrounds. The identification efficiencies are measured by $W\rightarrow \tau\nu$ and $Z\rightarrow \tau\tau$ events, and compared with the prediction of the Monte Carlo simulation. The energy scale uncertainties for tau leptons are determined by investigating single hadron calorimeter response, as well as kinematic distributions in $Z\rightarrow \tau\tau$ events.Speaker: Sofia Maria Consonni (INFN - Milano)
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Upgrade for the ATLAS Tile Calorimeter readout electronics at the High Luminosity LHCThe Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. I consists of about 1000 channels. The main upgrade will occur for the High Luminosity LHC phase (phase 2) scheduled around 2022. The upgrade aims at replacing the majority of the on- and off-detector electronics so that all calorimeter signals are directly digitized and sent to the off-detector electronics in the counting room. This will be done with minimum latency and maximum robustness. It will provide maximum information to the first level of the calorimeter trigger to improve the trigger efficiency as required to cope with the increased luminosity. Three options are presently being investigated for the front-end electronic upgrade. The first option is an improved version of the present system built using discrete components. The second alternative is based on the development of a dedicated ASIC, which will provide most of the functionality including the digitization. The third alternative is the development of a new version of the "QIE", a custom integrated circuit that incorporates a 4-range current integrator, on-board digitization, and timing. A demonstrator prototype read-out for a slice of the calorimeter with most of the new electronics, but also compatible with the present system, is planned to be inserted in ATLAS already in phase 0. The presentation gives an overview of the proposed design and summarize the status of the project.Speaker: Fernando Carrio Argos (University of Valencia)
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Upgrade of the CMS Hadron Outer Calorimeter with SiPM SensorsThe CMS Hadron Outer Calorimeter (HO) is undergoing an upgrade to replace the existing photodetectors (HPDs) with SIPMs. The chosen device is the Hamamatsu 3X3mm 50µm pitch MPPC. A system has been developed to be a “drop-in” replacement of the HPDs. A complete control system of bias voltage generation, leakage current monitoring, temperature monitoring, and temperature control using solid state Peltier coolers has been developed and tested. 108 channels of the system have been installed into CMS and operated for more that 1 year. The complete system of more than 2000 channels is in production and will be installed in the first LHC long shutdown scheduled for 2013.Speaker: Dr Jacob Anderson (Fermilab)
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Upgrade Plans for ATLAS Forward Calorimetry for the HL-LHCAlthough LHC data-taking is expected to continue for a number or years, plans are already being developed for operation of the LHC and associated detectors at a increased instantaneous luminosity about 5 times the original design value of 10$^{34}$ cm$^{-2}$ s$^{-1}$. The increased particle flux at this high luminosity (HL) will have an impact on many sub-systems of the ATLAS detector. In particular, in the LAr forward calorimeter (FCal), which was designed for operation at LHC luminosities, the associated increase in the ionization load at HL-LHC luminosities poses a number of problems that can degrade its performance, related to beam heating, space charge effects in the LAr gaps and HV losses due to increased current draws over the HV current-limiting resistors. One solution to these problems, which would require the opening of both endcap cryostats, is the construction and installation of a new FCal, with cooling loops, narrower LAr gaps, and lower value protection resistors. A second proposed solution, which does not involve opening the cryostats, is the installation of a small warm calorimeter in front of the FCal, resulting in a reduction of the particle flux to levels at which the existing device can operate normally. The talk will review the design of the ATLAS forward calorimeter and discuss the effects that are expected to degrade the performance at HL-LHC luminosities as well as the proposed upgrade scenarios.Speaker: Margret Fincke (Univ. of Victoria)
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Upgraded readout electronics for the ATLAS LAr Calorimeter at the Phase I of LHCThe ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards (LTDBs) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies a digital filtering and identifies significant energy depositions in each trigger channel. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. This poster presents the general concept of the upgraded LAr calorimeter readout together with the various electronics components to be developed for such a complex system. The R&D activities and architectural studies undertaken by the ATLAS LAr Calorimeter group will be described.Speaker: Mr Steffen Stärz (Technische Universitaet Dresden (DE))
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Applications
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The “Endo-TOF-PET-US” Project, A Multimodal Ultra-Sonic Probe Featuring Time-Of-Flight-Positron-Emission-Tomography in Diagnostic and Therapeutic EndoscopyAt first stage, the paper will briefly outline the functionality of this instrument, which aims at the development of new and higher performance imaging techniques with Time of Flight-PET capability in endoscopy and surgical oncology. The main fraction of the paper, however, will focus on the associated scientific and technological challenges to be met in fields such as scintillating crystallography, ultra-fast photodetection, highly integrated electronics, and system integration. Thereby we will highlight possible answers and solutions that derive from techniques and instrumentation prominent in high energy physics. Special emphasis is put on new developments of scintillators and diffractive optics to increase light output, and fast and compact photodetectors such as silicon photomultipliers (SiPMs) with the option of single SPAD readout. In view of the targeted coincidence time of flight performance of 200ps FWHM, equivalent to 30mm along the Line Of Response (LOR), our tests using specially doped LSO crystals together with commercial SiPMs (Hamamatsu) already produced a coincidence time resolution (CTR) of 180ps FWHM. An outlook of the future R&D until the completion of the project will be given at the end of the presentation. This project is funded by the European Commission’s FP-7 Cooperation Work Program: Health 2010.1.2-1.Speaker: Thomas Meyer (CERN)
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The AX-PET Experiment: A Demonstrator for an Axial Positron Emission TomographyThe AX-PET (AXial Positron Emission Tomography) experiment proposes a novel geometrical approach for a PET scanner, in which long LYSO scintillator crystals are placed axially in the tomograph. Arrays of WLS strips, placed behind each layer of crystals, provide the measurement of the axial coordinate. Both the crystals and the WLS strips are individually read out by G-APDs (Geiger-mode Avalanche Photo Diodes). Such a matrix of LYSO crystals and WLS strips allows for a 3D localization of the photons interactions (both photoelectric absorption and Compton scattering), with good spatial resolution and without compromising on the sensitivity of the detector. Two AX-PET modules have been built at CERN and fully characterized with point-like Na-22 sources, demonstrating competitive performance in terms of spatial and energy resolutions. Operated in coincidence, the two modules represent the demonstrator for a PET prototype, which has been successfully used for the reconstruction of images of several phantoms filled with F-18 in aqueous solution. The AX-PET detector concept, its performance, the reconstructed images of different phantoms will be described. We will also report about experimental studies of the digital Silicon Photomultipliers (dSiPM) from Philips as alternative photodetectors for the AX-PET. With their highly integrated read-out electronics and excellent intrinsic time resolution, dSiPMs may allow for compact detector modules with Time of Flight capability (TOF-PET).Speaker: Chiara Casella (ETH Zurich)
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Simultaneous Searches for WIMP Dark Matter and 0-ν ββ Decay at the Ton-Scale with a High-Pressure Xenon gas Electroluminescent TPCFuture experimental sensitivity goals for both WIMP dark matter and $0\nu \, \beta \beta$ decay searches converge on ton-scale active masses, and even much more. Background requirements for both searches have many similarities. Xenon is a prominent candidate for new experimental efforts in both topics at this scale. The question naturally arises whether both searches can be made in a single xenon-based detector – without significant compromise to either. In addition to new experimental results, we will present the rationale and some design and cost issues for a ton-scale electroluminescent TPC detector. In the coming era of severe fiscal pressures on large-scale science, it is important that a true dual-purpose detector be considered seriously.Speaker: David Nygren (LBNL)
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coffee break
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Compton Telescope Prototype Based on LaBr3-SiPM DetectorsA Compton telescope prototype for dose monitoring in hadrontherapy is under development at IFIC Valencia within the European project ENVISION. The detector characterization has been completed and the first imaging tests have been carried out with two detectors operated in time coincidence. The first detector consists of a 16x18x5mm LaBr3 continuous crystal coupled to a SiPM array from Hamamatsu Photonics. The array has 16 elements of 3mmx3mm size, in a 4.05x4.5mm pitch. The second detector is made of a continuous LYSO crystal coupled to a similar SiPM array. The characterization of the LaBr3 detector has shown an energy resolution of 6.5% FWHM at 511 keV. The spatial resolution is better than 1 mm FWHM, and the timing resolution is 2 ns FWHM. Data have been taken with the two detectors in coincidence, with a Na-22 point-like source in different positions, and images have been successfully reconstructed with real data. In addition, a GEANT4 simulation allows us to predict the imaging results with this device both in optimized conditions, and in realistic conditions. Larger detectors consisting of a 32mm x 36mm LaBr3 crystal coupled to four SiPM arrays (of the type previously tested and also monolithic) have been assembled and are being tested. Different readout systems, based on two SPIROC ASICs or on the VATAHDR ASIC are under study for this applicationSpeaker: Gabriela Llosa (IFIC/CSIC-UVEG Valencia)
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The MU-RAY Experiment. An Application of SiPM Technology to the Understanding of Volcanic Phenomena.The purpose of the MU-RAY project is to develop an innovative approach to the study of volcanoes and their monitoring based on a particle physics approach. The test site is Vesuvio: one of the higher risk volcanoes in the world. In this context, muon radiography is an innovative method of enormous impact. This is an imaging technique which relies on the measurement, by means of a cosmic ray telescope, of the absorption in the volcano of muons with near-horizontal trajectories, produced by the interactions of cosmic rays with the atmosphere. Since 2003 this technique has been successfully used on volcanoes in Japan, providing pictures of their vertices with resolutions much better than those obtained with the traditional techniques based on gravimeters. Researchers from Naples and Florence are currently involved in the construction and testing of a prototype telescope based on the use of bars of plastic scintillator with a triangular section whose scintillation light is collected by special fibers (wave length shifters) and transported to SiPM (Silicon photomultipliers). A complete prototype telescope, consisting of three xy scintillation planes and 1 m$^2$ active area has been assembled and is now under test. Details of the technology used including the Front End electronics will be presented along with first results obtained on the assembled scinitillator planes.Speaker: Raffaello D'Alessandro (INFN - Firenze)
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Flying over Radioactivity: the Elba CaseMonitoring the environmental radioactivity has been found to be a fundamental tool in order to keep under control the effect of anthropic modifications of topsoil. It is also a good probe to understand the geological structure of ground surface, faster and extremely cheaper with respect other type of measurements. A light and compact detector for airborne ground radioactivity survey (AGRS) has been developed. The detector is composed by 4 x 4 liters of sodium iodide detectors and its signals are acquired in list mode to analyze offline the spectra in different time intervals down to 2 seconds. The radioisotope abundances are derived by using the full spectrum analysis (FSA) with the non negative least square (NNLS) implementation, which avoids possible artifacts in the spectrum due to not constrained χ2 minimization. The detector signals are collected together with the informations on altitude and vehicle position which are acquired every 2 seconds. A small NaI(Tl) placed on top of the main detectors monitors installation on ultralight vehicles which guarantees higher flexibility and cheaper costs. In addiction to the natural radionuclides ($^{40}$K, $^{238}$U, and $^{232}$Th) the setup is also calibrated to give the $^{137}$Cs activity which is actually not negligible after Chernobyl incident. The system has been already used successfully on a complete monitoring of the Elba Island surface. Maps are obtained combining the measured data with geological information by using collocated CoKriging.Speaker: Antonio Caciolli (INFN - Padova)
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Applications - Poster Session
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Preliminary Results of a New Boron Coated Neutron DetectorThe proliferation of neutron detection application based upon $^3$He proportional counter has triggered a critical shortage of $^3$He gas. The annual demand of $^3$He for US homeland security alone has been evaluated more than the worldwide supply, with the effect of limiting the perspectives of nuclear physics applications that up to now rely strongly upon $^3$He-based detectors. Nowadays there is an increasing demand for alternative neutron detection technologies that can cover large solid angle, have low sensitivity to gamma background and, last but not least, low cost. We present a low cost neutron detector based upon a long cylindrical metal tube coated on the inside with a thin layer of $^{10}$B-enriched boron carbide ($^{10}$B$_4$C). $^{10}$B-rich layer captures neutrons: $^{10}$B undergoes to (n,$\alpha$) reaction producing an $\alpha$-particle and a $^7$Li recoil nucleus that travel off in opposite direction. The movement of both creates ion pairs when crossing the gas inside the cylinder. The best gas for neutron detection efficiency that could be used is boron trifluoride (BF$_3$) also enriched in $^{10}$B, but this gas is expensive and also on the black list of gases associated to the atmospheric ozone depletion. Nitrogen gas is used as low cost alternative. We present the preliminary performances of the detector 180 cm long and 6 cm diameter with a nitrogen pressure ranging from 1 to 3.5 atm, exposed to $^{252}$Cf source. Neutron relative detection efficiency compared to $^3$He set-up is evaluated and discussed.Speaker: Gianpiero Gervino (Università di Torino / INFN)
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Advances in Nuclear Emulsion DetectorsNuclear emulsion detectors have been widely used in nuclear and particle physics field especially for their excellent position resolution. Nowadays the state-of-the-art scanning microscopes, conceived and realized for experiments on neutrino physics, allow us to exploit the emulsion detectors in many fields mainly for the automated emulsion scanning and fast read-out achieved. Possible applications can be envisaged for example in geophysics, in the investigation of large hidden structures; in medical diagnosis and therapy, for the control and the characterization of ion accelerated beams to optimize radiation therapy treatments and to assure high performances in the production of isotopes; and, naturally in physics. Each application field has of course its own needs, for example in terms of angular resolution, robustness, or tolerance in high vacuum. To accomplish the different requirements, the Laboratory for High Energy Physics (LHEP) of the University of Bern has established an underground nuclear emulsion laboratory for nuclear emulsion handling, where an R& D activity is ongoing on many kinds of emulsion films and detector modules to optimise their performances according to the different purposes. The status and perspectives of this activity will be presented and progress on nuclear emulsion detector properties will be reported.Speaker: Dr Jiro Kawada (Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Bern, Switzerland)
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Development of a TOF PET Prostate Probe Readout SystemA compact readout system for a matrix of Silicon PhotoMultipliers (SiPM) has been developed in the framework of the TOPEM (TOf PEt Mri) INFN research program. The electronic system was designed to completely handle 128 pixels (a SiPM matrix), independently measuring both the arrival time of the incoming photons and the charge of the detected signal. The design is based on existing ASICs, developed in the framework of high energy physics, achieving a good compromise in compactness, speed and power. The controller of this system is interfaced to a Linux based PC running the data acquisition and event display code. The communication between the PC and our system is done using the USB 2.0 protocol, which can run up to 25 MB/s. Moreover in the controller can be realized a coincidence logic with an external detector, thus permitting to trigger the data acquisition, implementing a complete TOF-PET system. In parallel to this work a dedicated ASIC in under advanced development, implementing all the needed functions and giving a higher compactness, necessary to build a real detector to be used in clinical practice. A prototype with the basic building blocks has been developed and an evolved version is under design. We report here the design of the system and some laboratory measurements.Speaker: Paolo Musico (INFN - Genova)
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Development of Multi-Gap RPC for Medical ImagingAll over the world, mainly scintillator-based detectors are being used for PET Imaging. Due to the high cost of the existing systems, extensive R&D is being performed to find an alternative detector. Multi-gap Resistive Plate Chamber (MRPC) with time resolution ~ tens of pico-seconds is considered to be a good alternative. In this work we present the development of Bakelite and glass-based MRPC systems for their applications in PET imaging. MRPC is a gas filled detector made of highly resistive (bulk resistivity ~ $10^{11}$ - $10^{12}$ Ω cm, e.g. bakelite, glass) electrodes consisting of several small gas gaps (10 to 100 gaps of 0.2 mm to 1 mm width) and operates at atmospheric pressure. Smaller and larger number of gaps improves the time resolution. In MRPC, the total gas volume is divided into a number of small gaps with equal width by inserting intermediate resistive plates with bulk resistivity ~ $10^{11}$ - $10^{12}$ Ω cm between the two outermost resistive plates. A 20 cm × 20 cm MRPC prototype with four 0.6 mm gap has been fabricated with 1.6 mm thick P-120 grade bakelite sheets and tested in a cosmic ray test bench in the streamer mode with a gas mixture of argon, iso-butane and tetra-fluroethane (R-134a) in 55/7.5/37.5 volume mixing ratio. Silicone coating has been applied over all the inner surfaces to make the surface smooth.Speaker: Saikat Biswas (GSI - Darmstadt)
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First Full In-Beam PET Measurements of 62 MeV Protons onto a PMMA TargetPositron emission tomography (PET) is a valuable technique to monitor in-situ and non-invasively the delivered dose in ion beam therapy exploiting the beta+ activity produced in nuclear interactions along the beam path within the target volume. Due to the high beam-induced radiation flux and, at the same time, low statistics of annihilation photons, as of to date data are usually acquired during beam pauses or after irradiation. The main challenge to be solved in in-beam PET applications is data acquisition also during therapeutic irradiation (full in-beam measurement). Any attempt to acquire coincidence data during the beam has been unsuccessful. Our new PET prototype is based on two planar heads, each consisting of two independent detector modules with a joint active area of about 10x5 cm2. Each module is made of a position sensitive photomultiplier H8500 coupled directly to a scintillating LYSO crystal matrix of the same size. In recent improvements we have implemented a faster photon discrimination component that reduces the front-end dead time, and a modularized acquisition system that parallelizes the detector sensitive area. For the first time, the PET system has been able to sustain the single photon count rates and acquire coincidences during the beam, in conditions of sub-clinical beam currents. A study on the paralyzation conditions and dead time losses under different beam currents is presented and the feasibility of a full in-beam PET scanner is discussed.Speaker: Dr Katrin Straub (University of Pisa / INFN)
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High Resolution Detectors Based on Continuous Crystals and SiPMs for Small Animal PETHigh performance detectors based on continuous crystals coupled to SiPMs have been assembled and tested for the development of a sub-millimetre resolution small animal PET prototype. The prototype consists of two rotating heads, each made of a continuous 12x12mm LYSO crystal coupled to a monolithic, 64- pixel SiPM matrix from FBK-irst. Detectors with 5 mm and 10 mm thick crystals have been assembled and tested. A position determination method including depth of interaction (DOI) determination has been applied. The results of a detailed GEANT4 simulation including generation and transport of optical photons in the crystal has been satisfactorily compared with the experimental data. The intrinsic spatial resolution obtained in x and y with real data is 0.7 mm FWHM. DOI determination experiments with 5 and 10 mm thick crystals are being carried out. In order to test the imaging capabilities of the detectors, tomographic data have been acquired rotating the detectors around the source. Different Na-22 radioactive sources have been successfully imaged demonstrating the feasibility of the detector concept. A list-mode image reconstruction algorithm has been employed to fully exploit the continuous nature of the data. The FWHM of the reconstructed point sources ranges from 0.7 to 1 mm FWHM, which provides confidence that sub-millimetre spatial resolution is achievable with this detector concept.Speaker: Gabriela Llosa (IFIC/CSIC-UVEG Valencia)
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Low Gamma Activity Measurement of Meteorites Using HPGe-NaI Detector SystemThe radioactivity in natural samples like cosmogenic isotopes in meteorites, in Moon samples and in earth and ice in Antarctica, for example, produced by protons, neutrons, $\mu$ mesons and other charged particles is very low, usually below 0.001 disintegration per gram. Therefore, very special techniques are required, particularly if the sample can not be destroyed for chemical separation and also must have possibility of counting large amount of sample. For this purpose we have developed a highly selective Ge-NaI coincidence spectrometer, operating in the underground Laboratory of Monte dei Cappuccini (INAF) in Torino. We have then improved it by developing a multiparametric acquisition system, which allows better selectivity of the coincidence windows (e.g., in meteorites, to disentangle cosmogenic $^{44}$Ti signal from overlapping $^{214}$Bi, originated by naturally occurring $^{238}$U). Applications of this system to the study of meteorites (chondrite, achondrite and iron samples) will be described.Speaker: Paolo Colombetti (Università di Torino / INAF)
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Nuclear Emulsion Detectors: an Application to Volcanoes' Muon RadiographyThe recent development of very fast, automated scanning microscopes has made possible the application of nuclear emulsion detectors in large physics experiments, as well as in new interesting fields such as muon radiography of volcanoes. Muon radiography exploits the same basic principle as the standard medical radiography: it measures the absorption of quasi-horizontal cosmic-ray muons when traversing the edifice of a volcano, thus showing its internal structure in an average density map. Nuclear emulsion films represent a very interesting detector due to their high spatial (< 1 µm) and angular resolution (a few mrads), compactness and robustness. Moreover, they don't require electric power supply, are easily transportable on a mountain and do not require infrastructure. Here, we present the application of the nuclear emulsion technique to the muon radiography of Unzen and Stromboli volcanoes. We report preliminary results on a partial sample of emulsion films exposed in Japan at the Unzen mount. Futhermore we will describe the emulsion detector exposed at Stromboli and present a first look at their data.Speaker: Lucia Consiglio (Università di Napoli / INFN)
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Nuclear Physics Detector Technology Applied to Plant Biology ResearchThe detection of the emissions of radioactive isotopes through radioactive decay has been used for over 80 years as a tracer method for studying natural phenomena. Recently a positron emitting radioisotope of carbon: carbon-11 has been utilized as a $^{11}$CO$_2$tracer for plant ecophysiology research. Because of its ease of incorporation into the plant via photosynthesis, the $^{11}$CO$_2$ radiotracer is a powerful tool for use in plant biology research. Positron emission tomography (PET) imaging has been used to study carbon transport in live plants using $^{11}$CO$_2$. Presently there are several groups developing and using new PET instrumentation for plant based studies. Instrumentation originally developed for small animal PET has been modified for plant research as currently undertaken at Forschungszentrum Jülich. A PET plant imaging system has also been used in plant studies by a research group at the Japan Atomic Energy Agency. Brookhaven National Laboratory researchers have used a clinical human PET scanner to track the distribution of 11C labeled metabolites in plants. Thomas Jefferson National Accelerator Facility (Jefferson Lab) with the Duke University Phytotron is also involved in PET detector development for plant imaging. I will provide a brief overview Jefferson Lab’s use of nuclear physics detector technology to develop specific detectors for radiotracer imaging in plants and review some of the latest developments of the use of $^{11}$CO$_2$ tracer in plant studies.Speaker: Andrew Weisenberger (Jefferson Lab)
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Real Time 222Rn Measurements at Stromboli IslandGeophysical survey is employed for natural hazard and geological risk mitigation in many natural context, the real-time monitoring of several physical parameters is a powerful tool in the surveillance of volcanic and seismic area. Monitoring gas emanation from soil allows to get information about volcano activity, fault surveillance as well as the analysis of the hydrothermal systems. Radon emission from soil at Stromboli Island has been monitored since 2000 up to present days using an “ad hoc” multi-parameter real-time set-up able to measure 222Rn together with the environmental factors that mostly influence its soil concentration. The detection system is presented and discussed. From the data analysis, atmospheric pressure, soil humidity, soil temperature show to be the local variable factors that exert the main influence on radon results. Special care was paid for soil humidity values: from the real time collected data the great influence of soil humidity on radon variations is stressed. Radon concentration shows a stronger correlation with soil humidity than that with the widely investigated temperature variation. A signal processing analysis (Power Spectral Density by Fast Fourier Transform) has been done on the all data set: radon concentration peaks follow the variation of atmospheric pressure and soil temperature with an average time delay of 12h and 24h respectively. The performance of the detection set up are discussed in the frame of Stromboli geophysical survey.Speaker: Andrea Lavagno (Politecnico di Torino)
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Study of UT Glasses for Pixel Identification Performance in Multi-Anode PMT-Based Detectors for PETThe pixel identification capability is a common problem of gamma-ray detectors using matrices of scintillating materials coupled to position sensitive photodetectors. In Positron Emission Tomography (PET) systems an improvement of pixel identification leads to a reduction of the coding factor thus improving the spatial resolution of the system. In order to promote light spread and avoid overlap of responses, ultra-transmitting (UT) glasses can be inserted between the crystal and PMT array to gain pixel identification efficiency especially at the peripheral active area exploiting the enhanced light spread. The development of improved PET detector response regarding energy resolution and pixel identification quality is not only due to the selection of the material/geometry of the crystal, a suitable PMT and dedicated readout electronics, but depends also on the assembly of these hardware components. Our detector module dedicated for PET measurements consists of a scintillating LYSO crystal matrix (pitch 1.7 mm) coupled to a multi-anode PMT (Hamamatsu H8500C, active area 49 x 49 mm$^2$) and is read out by modular frontend electronics processing timing and anger-like position signals. In this work we have studied, in comparison to direct coupling, the effect of using UT glasses of three thicknesses, d = 0.7, 1.0, and 1.35 mm, on pixel identification performance (peak-to-valley ratio and linearity) and energy resolution for different regions of the active area of the PMT.Speaker: Dr Katrin Straub (University of Pisa / INFN)
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The 2 MeV Proton Linac Facility in BernThe RFQ linac originally used at LEP has been recommissioned and put back into operation at the Laboratory for High Energy Physics (LHEP) of the University of Bern. The primary goals are to enable the elemental analysis of given targets via particle-induced gamma emission (PIGE), and the detection of potentially dangerous materials with high nitrogen content using the gamma-resonant nuclear absorption (GRNA) technique. The 425 MHz RFQ provides a 2 MeV $H^-$ ion beam. At current settings, the beam repetition rate is 50 Hz with peak currents of 4--6 mA, yielding a particle flux of approximately $10^{13}$ ions per second. So far, beam instrumentation devices include an innovative R\&D beam profile monitor based on doped silica fibres, and a setup for emittance measurements using the pepper-pot technique. Furthermore, an adjustable focusing system with four permanent magnet quadrupoles (PMQs) was developed, capable of focusing the beam to millimetre spot sizes. For experiments, two options are currently available: For the PIGE technique, an extraction window with a 5 $\mu m$ stainless steel foil is used to extract the beam to air. The resulting proton beam has a range of 50 mm in air, corresponding to energies up to 1.5 MeV. The second option uses a carbon-13 target in vacuum to create a 9.17 MeV gamma-source via the $\mathrm{^{13}C(p,\gamma)^{14}N}$ reaction. This can be used for the detection of nitrogen using GRNA, and the calibration of detectors being developed at LHEP.Speaker: Mr Marcel Zeller (Albert Einstein Center for fundamental Physics, LHEP, University of Bern)
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UA9, an Experiment to Study Accelerator Crystal CollimationThe UA9 experimental equipment was installed in the CERN-SPS in March ’09 with the aim of investigating crystal assisted collimation in coasting mode. Its basic layout comprises silicon bent crystals acting as primary collimators mounted inside two vacuum vessels. A movable 60 cm long block of tungsten located downstream at about 90 degrees phase advance intercepts the deflected beam. Scintillators, Gas Electron Multiplier chambers and other beam loss monitors measure nuclear loss rates induced by the interaction of the beam halo in the crystal. Two Roman pots installed in the path of the deflected particles are equipped with a Medipix detector to reconstruct the transverse distribution of the impinging beam. Finally UA9 takes advantage of an LHC-collimator prototype installed close to the first Roman pot to help in setting the beam conditions and to analyze the efficiency to deflect the beam. I describe the hardware installed to study the crystal collimation during the various data taking periods in 2009-2011 and the challenges for the upgrade of the system to study crystal collimation on the LHCSpeaker: Dr Walter Scandale (INFN - Roma 1 / CERN)
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Front End, Trigger, DAQ and Data Management
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Fast Readout of GEM Detectors for Medical ImagingWe describe the design and implementation of a fast data acquisition (DAQ) system for GEM trackers applied to imaging and dosimetry in hadrontherapy. Within the AQUA project of TERA foundation a prototype of Proton Range Radiography of 30x30 cm$^2$ active area has been designed and built to provide in-beam integrated density images of the patient before treatment. It makes use of a pair of GEM to record position and direction of protons emerging from the target. A fast data acquisition rate close to a MHz will allow obtaining good resolution in-beam proton radiography in a few seconds. A dedicated fast front-end circuit for GEM detectors (GEMROC by Krakow University) is read by the FPGA based DAQ card (GR_DAQ), developed by the AQUA group. This module has been built around a Cyclone iii FPGA and a fast ADC and it is able to acquire and digitize the incoming signals with a continuous readout at 1MHz. 6 GR_DAQ modules cover the entire GEM bi-dimensional strip readout. A slave card collects the data from the GR_DAQs and sends them by USB to the PC. The software, developed on LabVIEW, provide multiple run modes, including electronics test, calibration and online data taking. It is foreseen to develop faster data analysis and monitoring software to provide real time or near-real time radiographic images. The same GEMs system is under evaluation (within ENVISION WP.3) to realize the in-vivo dosimetry, based on detecting secondary light particles during the treatment of the patient.Speaker: Mrs Martina Bucciantonio (TERA Foundation - University of Bern)
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NA62 Trigger SystemThe NA62 trigger system works with 3 trigger levels. The first trigger level is based on hardware, central trigger unit, so called L0 Trigger Processor (L0TP) and Local Trigger Units (LTU), which are located in the experimental cavern. Other two trigger levels are based on a software, computer farm, located on a surface. The L0TP receives information from 12 triggering sub-detectors asynchronously via ethernet , processes it, and then transmits a final trigger decision synchronously to each sub-detector through Trigger and Timing Control (TTC) system. The interface between L0TP and TTC system, which is used for trigger and clock distribution, is provided by Local Trigger Unit board (LTU). The LTU can works in two modes: global and stand-alone. In the global mode, the LTU is providing an interface between L0TP and TTC system. In the stand-alone mode, the LTU can fully emulate L0 processor and such provides independent runs for each sub-detector for testing or calibration purposes. In addition to emulation functionality there is implemented functionality which allows to synchronize the LTU with the L0 processor and the TTC system. For testing and debugging purposes there is implemented Snap Shot Memory (SSM) interface which can works in an input or an output mode. The trigger system will be permanently monitored by reading counters, with considerable built-in redundancy, at regular intervals.Speaker: Dr Marian Krivda (University of Birmingham)
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Prototype of a Gigabit Data Transmitter in 65~nm CMOS for DEPFET Pixel Detectors at Belle-IIThe Belle-II pixel detector (PXD) is the inner-most detector currently under development for the upgraded KEK-B factory in Japan. The PXD consists of two layers of DEPFET sensor modules located at radius 1.8 and 2.2~cm. Each module is equipped with three different ASIC types mounted on the detector substrate with flip-chip technique: (a) SWITCHER for generating steering signals for the DEPFET sensors, (b) DCD for digitizing the signal currents, and (c) DHP for performing data processing and sending the data off the module to the back-end data handling hybrid via 40~cm Kapton flex and 12--15~m twisted pair cables. To meet the requirements of the PXD data transmission, a prototype of the DHP data transmitter has been developed in a 65nm CMOS technology. The transmitter consists of a current-mode logic (CML) driver and phase-locked loop (PLL) which generates a clock signal for a 1.6~Gbit/s output data stream from a 80~MHz reference clock. A programmable pre-emphasis circuit in the CML driver compensates signal losses in the long cable by shaping the transmitted pulse response. The status of the chip developments for the DEPFET PXD will be shown and recent results of the performance of the Gbit link driver will be discussed.Speaker: Dr Tetsuichi Kishishita (University of Bonn)
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Latest Generation of ASICs for Photodetector ReadoutThe OMEGA microelectronics group has designed a new generation of multichannel integrated circuits, the “ROC” family, in AMS (AustrianMicroSystem) SiGe 0.35 µm technology to read out signals from various families of photodetectors. The chip named MAROC (standing for Multi Anode ReadOut Chip) has been designed to read out Multi Anode Photomultipliers (MAPMT), PARISROC (standing for Photomultiplier ARray In SiGe ReadOut Chip) to read out Photomultipliers (PMTs) and SPIROC (standing for SiPM Integrated ReadOut Chip) to readout Silicon PhotoMultiplier (SiPM) detectors and which was the first ASIC to do so. The three of them fulfil the stringent requirements of the future photodetectors, in particular in terms of low noise, radiation hardness, large dynamic range, high density and high speed while keeping low power thanks to the SiGe technology. These multi channel ASICs are real System on Chip (SoC) as they provide charge, time and photon-counting information which are digitized internally. Their complexity and versatility enable innovative frontier detectors and also cover spin off of these detectors in adjacent fields such as medical or material imaging as well as smart detectors. In this presentation, the three ASIC architectures and test results will be described to give a general panorama of the “ROC” chips.Speaker: Mrs Nathalie Seguin-Moreau (OMEGA/LAL/IN2P3)
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The Front-End Chip of the SuperB SVT DetectorThe asymmetric e+e- collider SuperB is designed to deliver a high luminosity with moderate beam currents and a reduced center of mass boost with respect to earlier B-Factories. The innermost detector is the Silicon Vertex Tracker which is made of 5 layers of double sided silicon strip sensors plus a Layer0 that can be equipped with short striplets detectors in a first phase of the experiment. In order to achieve an overall track reconstruction efficiency above 98% it is crucial to optimize both analog and digital readout circuits. The readout architecture being developed for the Front-End chips will be able to cope the very high rates expected in the first layers (up to 2 MHit/s per strip in the Layer0) and can potentially accommodate higher rates with a proper tuning of the buffer depth. The readout is based on a triggered architecture where each of the 128 strip channel is provided with a dedicated digital buffer storing a 4-bit TOT in conjunction with the related time stamp. The buffers are dimensioned considering the expected trigger latency and hit rate including suitable safety margins. A dedicated circuit handles the trigger logic and conveys the parallel streams of hits to the common chip output port. This architecture has been modeled by HDL language and investigated with a Montecarlo hit generator emulating the analog front-end behavior. Simulations showed that efficiency of the digital readout remained above 99.8% even for the stressing conditions of layer 0.Speaker: Dr Filippo Maria Giorgi (INFN Bologna)
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Gigahertz Waveform Sampling: An Overview and OutlookSwitched Capacitor Arrays (SCA) for fast waveform sampling are on the market since many years, but only recently they got an enormous boost due to fast and cheap CMOS chip technology. Many groups worldwide developed or are developing SCAs reaching up to 20 Giga-Samples per second and 12 bits with a power consumption orders of magnitude lower than traditional Flash ADCs. Several experiment deploy this technology with thousands of channels. Waveform sampling in the GHz range allow them waveform discrimination, effective pile-up rejection, and timing resolution down to a few pico seconds. This talk gives an overview of the technology, advantages and limitations, and compares SCA chips currently used in particle physics, astro-particle physics and Time-Of-Flight PET in medical applications. Current design projects are reviewed giving an outlook of what one might expect in the near future in this field, including dead-time free SCAs.Speaker: Dr Stefan Ritt (PSI)
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Front End, Trigger, DAQ and Data Management - Poster Session
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64-Channel, 5 GSPS ADC Module with Switched Capacitor ArraysWe present a 5 GSPS ADC/Data processing Module with up to 64 channels and 2,048 cells per channel, designed for fast-sampling, front-end applications. This is a 6U VME board, that incorporates 16 pieces DRS4 switched capacitor array chips developed at Paul Scherrer Institut, Switzerland. The 16 DRS 4 chips are grouped in four independent input blocks. A block, with a geometric size of 43 by 120 mm, has 4 pieces DRS 4 chips, 4 pieces AD9222 converters, and one Altera Stratix III FPGA. Each DRS 4 chip has 8 channels and each channel has 1024 sampling cells, which can be daisy-chained for larger sampling depth. This feature allows for a great level of flexibility in choosing the number of channels relative to capacitor array size, for a particular application. The first prototype PCB was designed for a sampling depth of 2,048 cells and 16 channels for a 42mm wide block, i.e. 64 channels for the 6U VME board. This compact form factor allows for these input blocks to be used as front-end electronics for the Cherenkov Telescope Array (CTA) cameras. In this VME board, the four blocks are fully independent and can run each in different modes without any conflict. A global FPGA, also a Stratix III device, provides control and interfacing. The module can run with a local oscillator or with input system clocks in the range of 20MHz to 550MHz. The front panel is fitted with a 2.5Gbps serial link transceiver. The full design and test results will be described.Speaker: Mr Mircea Bogdan (The University of Chicago)
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A 10-15 Gsa/s Switched Capacitor Array DAQ System for a Position & Time Sensing Large-Area Photo-DetectorA data acquisition (DAQ) system using 10-15 Gigasamples/second (Gsa/s) waveform sampling Application Specific Integrated Circuits (ASICs) for the readout of large active-area micro-channel plate photomultiplier tubes (MCP-PMTs) is presented. The development and characterization of these 20x20 sq. cm active-area MCP `tiles' are ongoing by the Large-Area Picosecond Photo-Detector Collaboration (LAPPD). Signals from the large-area MCP tile are acquired from a 50-ohm transmission line anode comprised of 30 parallel microstrips. The position, timing, and energy of the incident pulse are extracted from the waveforms that are recorded at both ends of the anode. The target geometry of the DAQ system is the very large-active area `Super-module', made of a 2x3 array of LAPPD MCP tiles, that requires 60 channels of compact, high bandwidth waveform sampling on both sides of the detector. For this task, a 6-channel, 15 Gsa/s, and 1.5 GHz bandwidth waveform digitizing ASIC, 'PSEC-4', was designed in 0.13 micron CMOS using a 256 sample-per-channel switched capacitor array architecture. Sampled waveforms are digitized on-chip and a region-of-interest in the data buffer is serially read off-chip for downstream analysis. The Super-module DAQ incorporates two hardware levels of FPGA-implemented ASIC control and waveform feature extraction. Ultimately, the reduced event data are sent to a computer via a gigabit Ethernet connection.Speaker: Mr Mircea Bogdan (The University of Chicago)
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A charge integrating silicon microstrip detector for XFEL and Synchrotron source applications.The pulsed beam of the new generation of FEL (Free Electron Laser) based X-ray sources places several challenges to the detector development: in particular the photon counting readout, a successful scheme in case of Synchrotron sources, cannot be used any longer. At the same time the data quality of photon counting systems, i.e. the low noise and the high dynamic range, is essential from an experimental point of view. In this context PSI has developed GOTTHARD, a charge integrating silicon strip detector which, thanks to a novel automatic gain switching feature, can provide single photon resolution, a dynamic range of 10000 12keV photons and a noise well below the photon statistics limit over the full dynamic range. The detector module is composed from 10 readout ASIC (Application Specific Integrated Circuit) wire bonded to a single silicon sensor with a 64x8mm^2 sensitive area for a total of 1280 channels at 50um pitch. A complete readout chain, from the high speed ADCs to the Gbit link for the data download, is also integrated on the board. Burst frame rates up to 1MHz (60kHz in continuous streaming) are achievable with the system. The detector and ASIC design will be presented together with the results from the characterization measurements. The performances of the system in XFEL and Synchrotron source applications will be discussed.Speaker: Aldo Mozzanica (Paul Scherrer Institut)
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A CMOS Front-End for MPPC-Based Detectors Aimed to TOF Applications with Fast Discriminator, Adjustable Arming Threshold and Constant-Fraction FunctionalityWe have designed and realised a Front-End chip for MPPC in standard CMOS 0.35$\mu$m technology. The channel presents a low input impedance in order to reduce as much as possible the recovery time of the sensor. This is achieved using the current domain for processing signals through the current conveyors (CCII) as building blocks of the channel. A current feed-back with low-pass filter has also been used to realise a sensitive improvement of the pile-up problem, in case of high repetition rate events. An independent arming threshold is available for each channel, providing the selection of the event through the peak level (proportional to the number of simultaneously hit pixels) reached by the signal. A constant-fraction functionality is present in order to reduce the well know time-walk problem. The delay in the correspondent branch is obtained by using an additional CCII block. The channel is also equipped with analog output and integrated analog output. The digital output of the discriminator channel has adjustable time width. The pilot chip is made up of five channels. All the values of the independent thresholds are stored in 10-bit registers as well as the the values of the trigger output width and the main polarisation current of the CCII blocks. All the registers are writable from a standard three-wire SPI. These features make the chip fully self-consistent. In this work we present and discuss the simulation results together with the preliminary test performed.Speaker: Dr Davide Badoni (I.N.F.N. Roma Tor Vergata)
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A Fast Hardware Tracker for the ATLAS Trigger SystemAs the LHC luminosity is ramped up to 3×10$^{34}$ cm$^{−2}$ s$^{−1}$ and beyond, the high rates, multiplicities, and energies of particles seen by the detectors will pose a unique challenge. The current three-level trigger is designed to allow a rate reduction from 40 MHz to about 400 Hz. The Fast Tracker (FTK) is an approved upgrade to the current ATLAS trigger system that will operate at full Level-1 output rates and provide high-quality tracks reconstructed in the entire inner detector by the start of processing in the Level-2 Trigger. This will allow to select signals with high purity selection and reject efficiently fakes from QCD background and therefore will free time in Level-2 farm for more refined selections. FTK solves the combinatorial challenge inherent to tracking by exploiting the massive parallelism of associative memories that can compare inner detector hits to millions of pre-calculated patterns simultaneously. The tracking problem within matched patterns is further simplified by using pre-computed linearized fitting constants and relying on fast DSPs in modern commercial FPGAs. Overall, FTK is able to compute the helix parameters for all tracks in an event and apply quality cuts in less than 100 μs. The system design is defined and the performance presented with respect to high transverse momentum (high-pT) Level-2 objects: b jets, tau jets, and isolated leptons.Speaker: Dr Guido Volpi (LNF)
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A Fast Readout Algorithm for Cluster Counting/Timing Drift Chambers on a FPGA BoardA fast readout algorithm for Cluster Counting and Timing purposes has been implemented and tested on a Virtex 6 core FPGA board. The algorithm analyzes and stores data coming from Helium based drift tube instrumented with a 1 GSa/s ADC and represents the outcome of balancing between efficiency and high speed performance, resulting in high efficiency peak data extraction on simulated signals as well as on experimental ones. A relative efficiency evaluation with respect to commercial sophisticated peak finding software (i.e. PeakFit) will be reported. Based on these results, the developed algorithm could be adopted in order to build an electronics VME board serving multiple fADC channels and be used as an on-line preprocessing stage for signals coming from drift chambers making use of Cluster Counting/Timing techniques.Speaker: Aurora Pepino (INFN - Lecce)
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A Front-End Electronics Board for MaPMT Single Photoelectron SignalsA Front-End design based on Commercial Operational Amplifiers for current sensitive amplifier has been developed to read-out signals from MaPMT. The overall design has been optimized for Single Photo-Electron Signal from the Hamamatsu H8500. The board has been developed in the framework of the PID detector of SuperB experiment to study in details the characteristic of the MaPMT chosen for the final integration. The signal collected by the current sensitive preamplifier is then fed into a ECL fast discriminator and a shaper for differential output. Performances in terms of channel sharing, gain and timing resolution will be discussed, presenting results obtained on a test bench and with the board plugged into the H8500 MaPMT illuminated by a picosecond laser.Speaker: Dr Francesco Giordano (INFN - Bari)
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A Novel Approach for Fast Scanning of Nuclear Emulsions with Continuous Motion of the Microscope StageNuclear emulsions have been used in particle physics experiments for many decades because of their unique spatial resolution. The use of nuclear emulsions as precise tracking detectors in large experiments has recently been made possible due to advances in the production of emulsion films and to the development of very fast automatic scanning devices. The present scanning speed of the European Scanning System (ESS), which has been developed within the OPERA Collaboration, is about 20 cm$^2$/h. In addition to the scanning of OPERA films, the ESS is used for other applications with ever-growing demands for improved scanning speed, such as the muon radiography of volcanoes. In order to further increase the scanning speed of the ESS, we are testing a novel approach different from the standard stop-and-go motion of the microscope stage in the horizontal plane. Indeed we perform data acquisition with the stage moving at constant speed, using an objective lens with wide field of view. Unlike the implementation realized in Japan where the movement of objective lens and stage are synchronized to pile up images of the same view, in this approach only the stage is moving horizontally. Thus images at different depths are not fully overlapped and special care is needed in the reconstruction. This approach can give a substantial increase in the scanning speed, especially for thin emulsion layers and wide field of view.Speaker: Dr Andrey Alexandrov (INFN - Napoli)
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A Theoretical Investigation of the Influence of High Irradiation on Signal to Noise Resolution (S/N) of Different Types of APS (Full Depleted FDAPS, MAPS and Hybrid Technology HPD)We use a simplified model for the pixel diode based on the differential equation to describe a process of diffusion and drift. This model allows to estimate the S/N resolution depended on the radiation absorbed dose. The estimations were done for the HPD, FDAPS, MAPS. We also studied the dependence the S/N resolution on the geometrical proportions of the diode's area. The results can be useful for developing of new PD with high radiation hardness.Speaker: Dr Vasily Kushpil (Nuclear Physics Instirute of ASCR)
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Advances in Emulsion-Based (ECC) Detectors Data Analysis and Reconstruction TechniquesNuclear emulsions quite popular in particle physics up to 60-th of the last century and nearly forgotten in following 30 years becomes an important option for high precision tracking detectors recently with the development of fast and completely automatic data acquisition systems makes the emulsion data treatment similar to one's of the electronic detectors. Tracking detectors based on nuclear emulsions has unique sub-micron position resolution, provides calorimetric information, has a long-term memory and particularly suitable for the study of rear events like neutrino interactions (OPERA detector). Them used also for muon radiography and medical applications. New promising application for the emulsions is a Dark Matter research. In this report reviewed specific methods relative for the emulsion data analysis, tracks, vertices and showers reconstruction, particles identification and event topology analysis. Specific and particularly important for the success of the emulsions data reconstruction alignment technique based on tracks pattern recognition in heavy signal/noise conditions will be discussed. Depending to the application different patterns -events particles, cosmic rays or Compton scattering particles can be used. Nowadays nuclear emulsions can be compared to a high-density DVD-like storage media, used in high-scale experiments and requires high-performance, specifically developed processing and data analysis tools algorithms and methods.Speaker: Valeri Tioukov (INFN - Napoli)
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Analog Front-end Electronics for the Outer Layers of the SuperB SVT: Design and Expected PerformancesThe Silicon Vertex Tracker (SVT) of the new SuperB collider will be composed of 6 different detector layers. The inner most layer (layer 0) will be composed by striplets or pixels; the other 5 detector layers will be double-sided strip detectors. The strip geometries and the foreseen hit-rates will change according the different layers. As a consequence, different optimization of the analog read-out electronics are needed in order to provide high detection-efficiency and low noise level in the different layers. Two readout ASICs are currently developed, one for layers 0-3, another for layers 4,5; they differ mainly in the analog front-end. In this work, we present the design and expected performances of the analog front-end for layers 4 and 5. For these layers, the microstrip detectors show a very high stray capacitance and high series resistance. In this condition, the noise optimization is our primary concern. A necessary compromise on the best peaking time to achieve an acceptable noise level together with efficiency and time accuracy has been found. We will present the design of preamplifier and shaper and the results of simulation of noise performance and efficiency (with the expected background rates). In addition, the design of the Time-over-threshold (TOT) and its use to correct the time-walk of the event trigger is discussed as well as the achievable timing accuracy of the circuit.Speaker: Dr Luca Bombelli (Politecnico di Milano /INFN)
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ARAMIS: Advanced Real-time Architectures of Data processing, Pattern Recognition and Data Transmission for Frontier Applications in High Energy Physics, High Reliability Systems and Visual Science.The ARAMIS project proposes a multi-disciplinary development of new real-time event selection architectures, in view of experiments at high luminosity colliders, such as HL-LHC and SuperB. The research program includes the development of novel approaches to real-time analysis: the design of new, extremely fast hardware processors: a mesh of Associative Memories and high speed serial links; the use of latest-generation Graphical Processing Units (GPU) in timing critical computing tasks; the development of new moderation techniques and fault-tolerant architectures capable to operate FPGAs safely under radiation. The project, which requires the highest competence in various fields, is the joint effort of Italian and Foreign Universities and Research Centres. Such collaboration allows ARAMIS to approach any subject of the program with expertise, methods, technologies and research structures at the state of the art. The developed tools will be specialized for the ATLAS, CMS, LHCb experiments and for application to the SuperB collider. The ultimate goals are to demonstrate the validity of the implemented techniques and to share common resources among experimental physicists in the coming years. ARAMIS is also meant to go beyond HEP. Strong similarities between advanced Real-Time analysis techniques and the psyco-physiology of the human vision mechanisms have recently emerged. A close collaboration between experts in the two fields will bring to new developments in both areas.Speaker: Dr Guido Volpi (INFN - LNF)
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Development of a New L1 Muon Trigger System and New Readout Electronics for the ATLAS MDT Chambers at High LHC LuminositiesThe planned upgrades of the Large Hadron Collider (LHC) towards higher luminosities require among other detector improvements also a significantly higher selectivity of the ATLAS level-1 muon trigger in order to efficiently reject the large low-momentum muon background without losing interesting signal events. The momentum resolution of the L1 muon trigger can be sufficiently improved by using the precision muon tracking detectors, the Monitored Drift Tube (MDT) chambers, in the trigger. This has the advantage that no new trigger chambers with higher spatial resolution need to be installed which is hardly possible for the largest part of the muon detector. A MDT chamber based muon trigger scheme has been developed and validated by simulation. Its implementation requires the replacement of the existing MDT on-chamber electronics which will also need higher radiation hardness and bandwidth. New readout chips in radiation hard technology and new frontend boards are under development. First test results will be shown.Speaker: Philipp Schwegler (Max-Planck-Institut fuer Physik, Munich)
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Development of a Read Out Driver for Micromegas at ATLASMicrostructured gaseous detectors are a possible replacement technology for the inner part of the forward-muon spectrometer of the ATLAS detecor, when the luminosity of the LHC will be increased beyond its design Value. During the winter 2012 shutdown, several small Micromegas detectors have been installed in ATLAS between the inner tracker and the calorimeter, as well as on the small wheel section. To read out these detectors along with the other ATLAS systems, a Readout driver has to be developed, that integrates this subsystem in the ATLAS data acquisition infrastructure, including the trigger handling, slow control, event building and data formatting. I report on the firmware development and the current status of this project, that is based on the SRS scalable readout system with Virtex6 FPGAs.Speaker: Mr Andre Zibell (LMU Munich)
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Electrical characterization of the low background Cu-PEN links of the CUORE experimentIn the CUORE experiment, under contruction at LNGS (Gran Sasso National Laboratories), Cu-PEN tapes are the first part of the connecting links between the detector and the front-end electronics. The sensors, NTD thermistors held at 10 mK inside the cryostat, are directly bonded to the Cu-PEN tapes. At the other end, the tape plugs into a ZIF connector on a kapton board at the inner thermalization stage. The tapes are about 2 m long, and must guarantee a negligible parasitic conductance between channels, of the order of 10 pA/V. Guards (grounded links) are used to prevent crosstalk between channels on each tape and between neighbouring tapes. Deep electrical characterization on each tape is to be performed, to ascertain that they comply with the requirements of the experiment. The characterization method is presented here. The first part is based on the time domain reflectometry (TDR) technique, to check the integrity of the electrical link without touching the pad end of the tape, to avoid any possible damage to the bonding pads. The second part of the characterization is focused on the parasitic impedance between links. For this characterization, a commercial electrometer is used; custom boards, with remote control capability, were built and used in order to be able to check the links in a vacuum, and reach sensitivities of the order of 1 pA/V and below.Speaker: Dr Claudio Gotti (INFN MIB)
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FE electronics for the Tagger of the BGO-OD experimentThe BGO-OD experiment, presently under construction at the electron accelerator ELSA at Bonn university, is intended for the systematic investigation of the photo-production of mesons off the nucleon. The experiment will use bremsstrahlung photons from an e\textsuperscript{-} beam incident upon a thin metal radiator. The photon energy will be measured via the deflection of the electrons in the magnetic field of a photon tagger. The electrons are detected in a 128 channel hodoscope with an expected rate up to 10MHz per single channel and 50MHz for the total detector. A coincidence between two neighbouring channels is required to suppress background. Additional to the measurement of the photon energy, time information from the detection of the deflected electrons will be used for coincidence measurements in the BGO-OD experiment. To match these requirements, a new tagger electronics was developed. The final prototype for the Front-End electronics was designed and tested, the final boards are presently on production. The test results will be presented in this talk.Speaker: Francesco Messi (Physikalisches Institut, Uni-Bonn)
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First GEANT4-based Simulation investigation of a Li-coated Resistive Plate Chamber for Low-Energy NeutronsA simulation study of the performance of a single-gap resistive plate chamber coated with Li- layer for the detection of low energy neutrons was performed by means of GEANT4 Monte Carlo code. Low energy neutrons were detected via $^7$Li(n,α) $^3$He nuclear reaction. To make the detector sensitive to low energy neutrons, Li- coating was employed both on the forward and backward electrodes of the converter. Low energy neutrons were transported onto the Li-coated RPC by GEANT4 MC code. The detector with convertor area of 5 x 5 cm$^2$ was utilized for this work. The detection response was evaluated as a function of incident low energy neutrons in the range of 25 meV to 100 meV. The evaluated results predicted higher detection response for the backward-coated converter detector than that of forward-converter coated RPC setup. This type of detector can be useful for the detection of low energy neutrons.Speaker: Prof. June-Tak Rhee (Konkuk-University)
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High Accuracy Injection Circuit for the Calibration of a Large Pixel Sensor MatrixSemiconductor pixel detectors, for particle tracking and vertexing in high energy physics experiments as well as for X-ray imaging, in particular for synchrotron light sources and XFELs, require a large area sensor matrix. This work will discuss the design and the characterization of a high-linearity, low dispersion injection circuit to be used for pixel-level calibration of detector readout electronics in a large pixel sensor matrix. The circuit provides a useful tool for the characterization of the readout electronics of the pixel cell unit for both monolithic active pixel sensors and hybrid pixel detectors. In the latter case, the circuit allows for precise analogue test of the readout channel already at the chip level, when no sensor is connected. Moreover, it provides a simple means for calibration of readout electronics once the detector has been connected to the chip. Two injection techniques can be provided by the circuit: one for a charge sensitive amplification and the other for a transresistance readout channel. The aim of the paper is to describe the architecture and the design guidelines of the calibration circuit, which has been implemented in a 130 nm CMOS technology. Moreover, experimental results of the proposed injection circuit will be presented in terms of linearity and dispersion. A complete analysis of noise performance will also be shown in the paper.Speaker: Emanuele Quartieri (University of Pavia, University of Bergamo)
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Influence of Neutrons on Signal Fluctuations for APD StructuresSilicon Avalanche Photodiodes (APD) working in proportional were chosen as a readout device for the PbWO4 crystals in the barrel of the CMS Electromagnetic Calorimeter (ECAL). During 10 years of operation, the CMS ECAL will be exposed to $2\times10^{13}$ neutrons/cm$^2$ under a severe radiation environment. In this study, we studied on the effect of photostatistical fluctuations from those of neutrons by using GEANT4 toolkit. Afterwards, the resulting photons have been tracked with a single-particle Monte Carlo simulation technique.Speaker: Adnan Kilic (Department of Physics, Uludag University, Bursa)
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Low resources FPGA-based TDC for HET detectors of KLOE-2 experiment at DAΦNETime to Digital Converters (TCDs) are very common devices in particles physics experiments. A lot of “off-the-shelf” TDCs can be employed but the necessity of a custom data acquisition system makes desirable the implementation of TDCs on the FPGAs. Most of the architectures developed so far are based on the tapped delay lines with resolutions down to 10 ps, obtained with high FPGA resources usage. Often such resolution is not needed and low resources occupancy TDC architectures are preferable. This makes possible the implementation on the same device of data processing systems and of other utilities. In order to reconstruct gamma-gamma physics events tagged in the KLOE-2 High Energy Tagger (HET), we need to measure the Time-Of-Flight (TOF) of the electrons and positrons from the KLOE-2 IP up to our tagging stations (11 m apart). A resolution better than the bunch spacing (2.7 ns) is required. We have developeded and implemented on a Xilinx Virtex-5 a 625 ps resolution TDC with embedded data acquisition systems and interface to the online FARM of KLOE-2.Speaker: Dr Lorenzo Iafolla (LNF)
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Modeling high impedance connecting links and cables below 1 HzHigh impedance connecting links and cables are modeled at low frequency in terms of their parasitic impedance to ground and to neigbouring connecting links. The parasitic impedance is usually considered to be the parallel combination of a resistance and a capacitance. While this model is adequate at moderate and low frequency, it proved to be not satisfactory at very low frequency, in the fractions of Hz range. Deep characterization was carried out on some samples down to 10 uHz, showing that an additional contribution to capacitance can emerge. A model was developed to explain and account for this additional contribution. This contribution may impact the shape of signals in experiments which use high impedance sensors, such as the thermistors of the CUORE and Lucifer experiments.Speaker: Dr Gianluigi Ezio Pessina (MIB)
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New Electronics Developments for the SuperB Charged Particle Identification DetectorsNew generation flavor factories like SuperB require very good charged particle identification. In SuperB, the barrel region is covered by a new detector based on the successful BaBar DIRC: the FDIRC. Each of the 12 FDIRC photon cameras will house 48 MaPMTs, providing excellent timing capability for single photons (TTS ~140 ps). When compared with BaBar, the increase in luminosity (×100) and background makes it necessary to implement new front-end electronics with higher time precision (~100 ps rms), higher hit rate capability (few MHz/pixel), and small dead time (< 5% at 1MHz). The electronics is based on an ASIC with a new architecture, performing simultaneous time and charge measurement at high rate. To extend this excellent coverage, an additional detector has been designed for the SuperB forward region. The 12 thin fused silica tiles arranged perpendicular to the beam axis generate Cherenkov photons which will propagate until they are detected by fast MCP-PMTs. Both the photon timing and position are recorded to perform the pi/K separation. The need for excellent time resolution requires both fast detectors and new ultra-fast electronics, developed jointly by LAL Orsay and CEA/IRFU. It is based on a new generation TDC able to reach an accuracy of a few ps while working directly with analog signals. The poster will focus on these two original electronics developments and describe the different tests already performed, including those on the SLAC Cosmic Ray Telescope.Speaker: Dr Nicolas Arnaud (LAL-Orsay)
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New-EEE, A New Control and Data Acquisition Software for the EEE TelescopesThe EEE (Extreme Energy Event) project studies extensive cosmic ray air showers by means of a network of tracking telescopes installed in high school buildings distributed all over Italy. The telescope, made up of multi-gap resistive plate chambers (MRPC), is built in collaboration with schools by the same students and teachers that will operate the system afterwards. In the current configuration the MRPC front-end electronics is interfaced with a VME-based system of custom boards and commercial multi-hit TDCs. The upcoming phase of expansion of the telescope network has recently triggered a complete re-design of the chambers control and monitoring, data acquisition interface via a single USB link and user-defined trigger selection. The new design resulted in a very compact and versatile system with a significant cost reduction that will allow more schools to enter the EEE program and to afford the initial costs. The system architecture will be described in detail, with emphasis on the integration of data acquisition, trigger and GPS into a single unit, control and monitoring of the chamber parameters. Performances of a fully functional prototype will be presented and plans for future operation will be reported.Speaker: Dr Federico Pilo (INFN - Pisa)
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Performance of the ATLAS Jet TriggerThe ATLAS jet trigger system has a 3-level structure, and is based on the concept of Region Of Interest, where only regions of the detector around interesting Level-1 objects are reconstructed at the higher levels. This strategy is not well-suited for multi-jet events since it leads to pathologies and efficiency losses. This philosophy has been changed for the jet trigger during 2011, and we now have the possibility of unpacking the full calorimeter at Event Filter. For 2012, full calorimeter unpacking will also be possible (for a small subset of the events) at an intermediate level between Level-1 and Level-2. We also moved to the use of calibrated scale at trigger level, and to the application of noise cuts to reduce rate spikes. We will present the performance of the jet trigger in 2011 and from the first runs of 2012.Speaker: Dr Matthew Tamsett (Louisiana Tech University)
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Silicon Photomultiplier's Gain Stabilization by Bias Correction for Compensation of the Temperature FluctuationsMeasurements using the Silicon Photomultiplier (SiPM) as photon detector have required stable gain specially for a sensitivity on the level of a single photon. The temperature has a significant influence on the value of detector’s gain. SiPM have been used in many applications, where heat is emitted mainly by other devices. In order to keep gain of a detector on a stable level, these applications would have to be kept in controlled, air conditioned rooms. Very often it is hard to control the temperature, especially in large systems. The paper presents a method for compensation of SiPM gain variation caused by temperature fluctuations. Instead of stabilizing the temperature we can correct the bias voltage of the detector. Gain of the SiPM is a linear function of the temperature and the bias. Increase of the temperature leads to the decrease of gain. On the other hand, an increase of the bias makes value of the gain higher. These dependencies have been bounded by linear function: G(V,T)=aT+bV+c, where G stands for gain, T for temperature and V for bias voltage. The values of the coefficients a, b and c depend on the SiPM model and have been calculated from set of measurements of the gain of SiPM. Using this function we have created a measurement setup where any fluctuation of the temperature has been automatically compensated by setting suitable bias voltage. Results of the measurements of three different types of SiPM (supplied by Hamamtsu, SensL and FBK) has been presented.Speaker: Mr Piotr Dorosz (AGH University of Science and Technology)
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Simulating the Radiation Monitor for the SuperB experimentRadiation control in the region close to the interaction point is a crucial task for the success of the SuperB experiment. In addition to being necessary for the safe operation of the detectors, it can also contribute information to luminometers and, to some extent, to trigger and reconstruction. The detector itself is now in its prototyping phase, with different technologies being evaluated. One important parameter to drive the choice of the detection technology are the expected radiation levels. These could, in principle, be roughly estimated by comparing/scaling direct observations in similar colliders. However, since the operating conditions of the SuperB collider are unprecedented, the design of the interaction region has been carefully tuned in order to minimize the impact of the accelerator-related background processes on the subdetectors. The impact of this newly designed interaction region on the radiation levels is such that all extrapolations from current experiments are unreliable. The only possibility in the present design phase is therefore to use a detailed simulation program to infer what doses the detector will have to cope with. We will present the current simulation effort, together with results from recent simulation campaigns, with emphasis on the interplay between simulation and design/implementation.Speaker: Dr Andrea Di Simone (ROMA2)
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Simulation Response of B4C-Coated PPAC for Thermal Neutrons Using GEANT4 Monte Carlo ApproachIn this work, we report a technique employed for the detection of thermal neutrons using the parallel plate avalanche counter (PPAC). In order to make the detector sensitive to thermal neutrons a thin layer of $^{10}$B$_4$C has been coated on the forward electrode of the PPAC configuration. Upon falling on the converter coating, charged particles were generated via the $^{10}$B(n,α)7Li reaction. In this simulation study, thermal neutrons have been simulated using the GEANT4 MC code, and the response of the detector has been evaluated as a function of neutron energy. For a better understanding of the simulation response, the performance of the detector has been found using the two different physics list i.e., QGSP_BIC_ HP and QGSP_BERT_HP. The obtained results predicted that such boron-carbide based PPAC can be potentially utilized for thermal neutron detection. A complete description of the detector configuration and the simulation results are also presented.Speaker: Prof. June-Tak Rhee (Konkuk-University)
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The ATLAS Hadronic Tau Trigger: Status, Performance and PlansHadronic tau decays play a crucial role in the search for physics beyond the Standard Model as well as in Standard Model measurements. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production cross section of QCD processes, designing and operating a trigger system with the capability to efficiently select hadronic tau decays, while maintaining the rate within the bandwidth limits is a difficult challenge. This contribution will summarize the status and performance of the ATLAS tau trigger system during the 2011 data taking period, and the upgrades put in place for the current 2012 run. Special emphasis will be placed on the key role of identification and rejection capabilities of the different sub-detectors of ATLAS and the algorithms used. Finally, first results and prospects on the performance in 2012 will be presented.Speaker: Andres Jorge Tanasijczuk (Simon Fraser University)
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The ATLAS Trigger System: Performance and EvolutionDuring the data taking period from 2009 until 2011, the ATLAS trigger has been used very successfully to collect proton-proton data at LHC centre-of-mass energies between 900 GeV and 7 TeV. The three-level trigger system reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 300 Hz. Using custom electronics with input from the calorimeter and muon detectors, the first level rejects most background collisions in less than 2.5 ns. Then follow two levels of software-based triggers. The trigger system is designed to select events by identifying muons, electrons, photons, taus, jets, and B hadron candidates, as well as using global event signatures, such as missing transverse energy. We give an overview of the performance of the different trigger selections based mainly on the experience during the 2011 LHC run. Distributions of selection variables used by the different trigger selection are shown and compared with the offline reconstruction. Examples of trigger efficiencies with respect to offline reconstructed signals are presented and compared to simulation. These results illustrate that we have achieved a very good level of understanding of both the detector and trigger performance. Furthermore, we describe how the trigger selections have evolved with increasing LHC luminosity to cope with the increasing pileup conditions. If already available the initial experience from the 2012 run will be presented.Speaker: Antonio Sidoti (ROMA1)
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The CBC and CBC2 microstrip readout chips for the upgraded CMS Tracker at HL-LHCThe CMS Tracker will be replaced in the next decade. Layouts under consideration include modules to deliver information to the L1 trigger. One such module would be constructed of two layers of microstrip sensors a few cm in length, and separated by a few mm, with both sets of microstrips sharing the same front-end readout chips. The CMS Binary Chip is designed using 130 nm CMOS technology with 128 channels DC-coupled to sensors of n- or p-type silicon. It is a successor to the APV25, used in the current tracker, and has similar features but transmits unsparsified binary data stored in a 256 deep pipeline clocked at 40 MHz after a trigger. New features include on-chip DC-DC voltage conversion. The first version of the CBC has been successfully studied in the laboratory and in a test beam. The CBC is well suited for use in “stacked” modules to identify hits associated with high transverse momentum particles. A second version is in the final stage of design. CBC2 has 254 input channels and will be bump-bonded on 250µm pitch to a substrate. It incorporates logic to identify L1 trigger primitive “stubs”: high pT candidates isolated by selecting correlated hits between the two microstrip sensors. The main features of the CBC and results from tests will be presented. The status of the CBC2 design and additional functionality, including trigger coincidence logic, which reject wide clusters and correct for the position of the module in the R-phi plane, will be described.Speaker: Prof. Geoff Hall (Imperial College London)
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The CHarged ANTIcounter for the NA62 experiment at CERNThe NA62 experiment at CERN aims at the very challenging task of measuring with 10% relative error the Branching Ratio of the ultrarare decay of the $K^+\to\pi^+\nu\bar{\nu}$ , which is expected to occur only in about 8 out of 10$^{11}$ kaon decays. Beam induced background, caused by inelastic interactions of the hadron beam with the Si based detector which measures kaon momentum (the so called Gigatracker, GTK) can mimic the signal in case only one pion is detected downstream. To suppress this background we have designed the so called CHarged ANTIcounter (CHANTI) i.e. a series of six guard rings, to be operated in vacuum, and covering a wide angular region downstream the last GTK station. CHANTI must have time resolution below 1 ns, must be highly efficient in detecting charged particles and must cope with rates which in the inner part can be some kHz/cm$^2$. We have adopted a solution based on triangularly shaped scintillator bars coupled with fast wavelength shifting fibers and individually read by means of Silicon Photomultipliers (SiPM). The full scale prototype of one ring has been built and tested using a prototype front end board which allows fast amplification and individual channel fine bias setting with O(mV) resolution and 0.1% stability .We show first results on the response of the detector to minimum ionizing particles as well as on its time resolution, which are well in line with the specifications.Speaker: Paolo Massarotti (Naples University & INFN)
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The Data Acquisition System of the SuperB-SVT Beam TestA prototype hybrid pixel detector and a high resistivity silicon detector with short strips, developed by the VIPIX collaboration and aimed at equipping the layer 0 of the SuperB vertex detector, have been tested in September 2011 with a 120 GeV pion beam at the SPS H6 beam line at CERN. The detectors under test were placed at the center of a reference telescope consisting of six planes with double-sided readout. The main elements of the data acquisition and trigger systems were two programmable VME 9U custom boards organized in a master-slave configuration and responsible for programming the frond-end chips of both the reference telescope and the detectors under test. The master board was also devoted to the distribution of the synchronization clock and the triggers. Both boards acted as event builders, packing information from the telescope and the DUTs in events that were then sent out via optical links to a receiving card on a remote PC. The details of the data acquisition and trigger systems are presented in this poster together with their final performance at the beam test.Speaker: Dr Carla Sbarra (INFN - Bologna)
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The design of fast analog channels for the readout of strip detectors in the inner layers of the SuperB SVTSix layers of microstrip detectors are foreseen in the present baseline design of the SuperB Silicon Vertex Tracker. Different strip pitches and lengths will be used in the various SVT layers; however, the capability of standing a high background rate and of operating with high hit detection efficiency will be a common feature of the innermost layers. These requirements set the need for a readout chip with analog channels with a short signal shaping time (25 to 100 ns in layers 0 – 3) to achieve an adequate time stamp resolution and a small pulse overlap. These channels are also required to provide a 4-bit hit amplitude resolution for dE/dx measurements. A new chip is being designed in a 130 nm CMOS process to comply with these specifications. This paper will discuss the solutions that are adopted in this chip for the various blocks of the analog channels, and will present the simulation results for the current design along with the expected performance in terms of parameters such as signal-to-noise ratio, dynamic range, linearity, power dissipation.Speaker: Luigi Gaioni (INFN Pavia)
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The electronics system of the TOTEM T1 telescope.Totem is an experiment located at CERN and devoted to the measurement of the proton-proton elastic and total cross section at LHC. TOTEM and CMS foresee a program of common measurements on diffractive physics. This presentation will be focused on the design of the read-out system of the T1 inelastic telescope, equipped with Cathod Strip Chambers. We will present the complete electronic readout chain of the Cathode Strip Chambers: the anode and cathode front-end boards, the readout-control card, the architectures of the trigger system and the slow control and fast command distribution chains. Key features of this system are high radiation tolerance and data path, slow control, fast command and trigger compliant with the CMS standards. We will report on the performance of the full read-out chain in lab and on the LHC beam at CERN.Speaker: Dr Saverio Minutoli (INFN Genova)
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The JEM-EUSO time synchronization systemThe JEM-EUSO instrument is a wide-angle refractive telescope in near-ultraviolet wavelength region being proposed for attachment to the Japanese Experiment Module onboard ISS. The instrument consists of high transmittance optical Fresnel lenses with a diameter of 2.5 m, a focal surface covered by 4932 MAPMTs of 64 pixels, front-end readout, trigger and system electronics. The tracks generated by the Extensive Air Showers produced by UHE primaries propagating in the atmosphere, are reconstructed on the focal surface by registering in a cyclic memory, every 2.5 microseconds, the data coming from the 315648 pixels and by selectively retrieving only the interesting ones on the occurrence of a second level trigger. In order to guarantee the correct time alignment of the events and to measure the arrival time of the event with a precision of few microseconds, a clock distribution and time synchronization system for the focal surface electronics has been developed. In this poster we will present the status and the technical solutions adopted so far. We will also describe the version of the system developed for the EUSO-BALLOON experiment, a JEM EUSO pathfinder mission, planned for the 2013, in which a telescope of smaller dimension than the one designed for the ISS, will be mounted on board a stratospheric balloon.Speaker: Dr Valentina Scotti (INFN - Napoli)
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The Pixel Detector Readout ASIC for the Micro Vertex Detector of the PANDA ExperimentThe PANDA experiment at the future FAIR facility under construction near the GSI research center at Darmstadt, Germany, aims to the study of the antiproton-proton and antiproton-nucleus annihilation reactions. The Micro Vertex Detector (MVD) is the innermost part of the experiment and will consist of silicon pixel and silicon strip detectors. Owing to the high track density (up to 11.4 MHz/cm$^2$) and the absence of an hardware trigger signal, an ASIC based custom solution for the electronic readout of the pixel detector has been chosen. The ASIC, named ToPiX, will provide the time position of each hit and a measure of the charge released with the Time over Threshold (ToT) technique. A reduced scale prototype in a CMOS 0.13 $\mu$m technology has been designed and tested. The prototype includes four columns made of 128 pixel cells, four columns of 32 cells and and the end of column readout with a 32 cells deep FIFO for each double column. Each cell embeds a charge amplifier with constant current feedback capacitor discharge, a comparator with per cell adjustable threshold, 12-bits leading and trailing edge register for time and ToT measurement and an 8 bits bit configuration register. All the readout logic has been SEU-hardened by design using either Hamming encoding or triple redundancy. The chip has been tested both electrically via a test pulse input and connected to a detector in a beam test. Radiation test for both TID and SEU tests have been performed.Speaker: Daniela Calvo (INFN - Torino)
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Trigger-Less Readout System With Pulse Pile-Up Recovery for the PANDA Electromagnetic CalorimeterThe PANDA collaboration at FAIR, Germany, will investigate yet undiscovered charm-meson states and glueballs in antiproton annihilations to study QCD phenomena in the non-perturbative regime. A multi-purpose detector for tracking, calorimetry and particle identification is presently being developed to run at high luminosities providing annihilation rates up to 20 MHz. The PANDA electromagnetic calorimeter (EMC) is composed of PbWO4 (PWO) crystals which are cooled to -25 ºC and coupled to large-area avalanche photo-diodes or vacuum photo-triodes /-tetrodes. Individual crystals will be exposed to single-detector hit rates up to 500 kHz causing a pileup probability up to 15%. The photo-sensor signals are continuously digitized by Sampling ADCs (SADCs) and analyzed on-line in FPGAs to detect hits and extract energy and time information. The on-line digitizer algorithm was designed , optimized and implemented in VHDL for a Xilinx FPGA. In order to gain flexibility and selectivity at high data rates, the PANDA collaboration develops the trigger-less readout system: all detector channels are self triggering entities and able to detect and pre-process signals and to transmit only the physically relevant information, sorted according to precise time-stamps. We present test results for the prototype of a trigger-less readout chain of the PANDA EMC including as key ingredient the synchronous optical link connection for clock signals and time-synchronization commands.Speaker: Prof. Herbert Loehner (KVI)
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Solid State Detectors
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Development of the DEPFET Sensor with Signal Compression: a Large Format X-ray Imager with Mega-Frame Readout Capability for the European XFELWe present the development of the DSSC: an ultra-high speed detector system for the European XFEL in Hamburg. The DSSC will be able to record X-ray images with a maximum frame rate of 4.5MHz. The system is based on a silicon pixel sensor with a new non-linear DEPFET as a central amplifier structure and has detection efficiency close to 100% for X-rays from 0.5 keV up to 10keV. The sensor will have a size of 210x210 mm$^2$ composed of 1024x1024 pixels. 256 readout ASICs are bump-bonded to the detector in order to provide full parallel readout. The signals coming from the sensor are processed by an analog filter, digitized by 8-bit ADCs and locally stored in a SRAM. In order to fit the dynamic range of 10$^4$ photons of 1keV per pixel into a reasonable output signal range, achieving simultaneously single 1keV photon resolution, a strongly non-linear characteristic is required. The proposed DEPFET provides dynamic range compression at the sensor level. The most challenging property is that the single 1keV photon resolution and the high dynamic range are accomplished within the 220ns frame rate. The main building blocks and properties of the system will be discussed. The experimental characterization of first non-linear DEPFET will be presented. New experimental results obtained coupling this newly fabricated DEPFET prototype to an ASIC prototype which comprises the complete readout chain from the analog front-end to the ADC and the memory will be shown.Speaker: Dr Matteo Porro (Max Planck Institut for Extraterrestrial Physics - Semiconductor Laboratory)
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Characterization of the first prototypes of Silicon Photomultipliers with bulk-integrated quench resistor fabricated at MPI semiconductor laboratorySilicon Photomultipliers (SiPMs) have the potential to replace conventional photomultiplier tubes in many applications. Thus, the improvement and full understanding of SiPM properties is of general interest. Conventional SiPM concepts use deposition of a high ohmic polysilicon layer as quench resistor. This, in turn, acts as an obstacle for light and reduces the fill factor which gives limitation to the maximum photon detection efficiency (PDE). A new detector concept in which the quench resistor is integrated to the silicon bulk was developed at Max-Planck semiconductor laboratory. Therefore, a metal and polysilicon free entrance window can be realized which offers an improvement in PDE. For electrical separation and suppression of optical cross talk (OCT) an insensitive area (gap) between neighbouring cells is required. Based on simulations a first prototype production was performed and devices with different combinations of cell size and gap were fabricated, providing the opportunity to study the influence of these parameters on the detector performance like PDE, recovery time, OCT, etc. Advantages and disadvantages of the concept will be presented. Results of the characterization of this first SiPM prototype, including the influence of geometrical variations will be presented and discussed. An outlook on possible future developments of the concept will be given.Speaker: Mr Christian Jendrysik (Max-Planck-Institute for Physics)
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3D silicon detectors3D silicon detectors were successfully fabricated in different facilities in Europe and USA in 2010-2011 by a collaboration of ~90 scientists and processing laboratories. Sensors with full compatibility with large pixel readout electronic chips have currenly an yield of ~60%. In 3D, electrodes are micromachined inside the silicon wafer bulk rather than being implanted on its surfaces. This novel dimension in silicon imaging opens new possibilities for the future. This presentation will explore the status of 3D silicon technology, its strengths, technological challenges and perspectives for future applications is high energy physics and other areas.Speaker: Dr Cinzia Da Via (Manchester University)
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Recent Results of CERN RD39 Collaboration on Development of Radiation Hard Si Detectors Operated at Low to Cryogenic TemperaturesRecent Results of CERN RD39 Collaboration on Development of Radiation Hard Si Detectors Operated at Low to Cryogenic Temperatures will be presented in this talk. It has been found, in comparisons of results of simulation and charge collection data of pad and strip detectors, the CID (charge-injected-diode) operation mode of Si detectors reduces the free carrier trapping, resulting in a much higher charge collection at the SLHC fluence than that in a standard Si detector. The reduction in free carrier trapping by almost one order of magnitude is due to the fact that the CID mode pre-fills the traps, making them neutral and not active in trapping. It has been found that, electron traps can be pre-filled by injection of electrons from the n+ contact The CID mode of detector operation can be achieved by a modestly low temperature of $\approx$ -40 $^o$C and a operation bias of <600 volts. Results of one CID detector application as LHC Beam-Loss-Monitor (BLM) will be presented. Non-irradiated Si detectors has been shown, with tests by the 10 GeV/c beam from PS and by laser using our cryogenic TCT (transient-current-technique), to work quite well at LHe temperature (4 K), which are very stable with no polarization and good charge collection efficiency. Results of irradiated CID Si detectors as BLM will also be presented, and we expect that they will work just as good due to their radiation hardness.Speaker: Mr Zheng Li (BNL)
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Development of CVD Diamond Beam Monitors at cryogenic and room-temperature for LHC, CNGS and the ATLAS ExperimentIn recent developments we have studied CVD diamonds as beam monitors for a large variety of applications. We will present test results on diamond detectors used as beam loss monitors operating at ultra-cold temperatures (1.9K) for future use at LHC, as muon beam monitor in the CERN CNGS facility and as diamond pixel modules to monitor luminosity near the interaction point of the ATLAS experiment. For the new series of triplet magnets, the LHC Beam Instrumentation Group seeks a detector concept that provides full functionality at ultra-cold temperatures (1.9 K). We will present results of measurements of the temperature dependence of fundamental diamond quantities such as carrier drift mobility and velocity, total charge yield, lifetime and detrapping time constants. The presentation will also show recent results of two applications of CVD diamonds: For CNGS (CERN Neutrinos to Gran Sasso) CVD diamonds have been used since October 2011 to measure in the CNGS facility at CERN the time structure of the muon beam. The diamond system allows to independently measure the ‘start-signal’ for the neutrino time-of-flight measurements and to study any systematic effects along the CNGS secondary beam-line. For the ATLAS Experiment a diamond pixel detector is currently under development. The diamond pixel modules are based on the new ATLAS FEI4 pixel chip and will provide bunch-by-bunch luminosity measurements through charged particle tracking near the interaction region of ATLASSpeaker: Dr Heinz Pernegger (CERN)
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coffee break
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High rate particle tracking and ultra-fast timing with a thin hybrid silicon pixel detectorThe Gigatracker (GTK) is a hybrid silicon pixel detector designed for the NA62 experiment at CERN. The beam spectrometer, made of three GTK stations, has to sustain high and non-uniform particle rate (~1 GHz in total) and measure momentum and angles of each beam track with a combined time resolution of 150 ps. In order to reduce multiple scattering and hadronic interactions of beam particles, the material budget of a single GTK station has been fixed to 0.5% X$_0$. The expected fluence for 100 days of running is $2\times10^{14}$ 1 MeV neq/cm$^2$, comparable to the one foreseen in the inner trackers of LHC detectors during 10 years of operation. To comply with these requirements, an efficient and very low-mass (<0.15% X$_0$) cooling system is being constructed, using a novel microchannel cooling silicon plate. Two complementary read-out architectures have been produced as small-scale prototypes: one is based on a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other makes use of a constant-fraction discriminator followed by an on-pixel TDC. The read-out ASICs are produced in 130 nm IBM CMOS technology and will be thinned down to 100 μm or less. An overview of the Gigatracker detector system will be presented. Experimental results from laboratory and beam tests of prototype bump-bonded assemblies will be described as well. These results show a time resolution of about 170 ps for single hits from minimum ionizing particles, using 200 μm thick silicon sensors.Speaker: Dr Massimiliano Fiorini (Université Catholique de Louvain)
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Measurement Results of DIPIX Pixel Sensor Developed in SOI TechnologyThe development of integration type pixel detectors presents interest for physics communities because it brings optimization of design, simplicity of production - which means smaller cost, and reduction of detector material budget. During the last decade a lot of research and development activities took place in the field of CMOS Silicon-On-Insulator (SOI) technology resulting in improvement in wafer size, wafer resistivity and MIM capacitance. Several ideas have been tested successfully and are gradually entering into the application phase. Some of the novel concepts exploring SOI technology are pursued at KEK; several prototypes of Dual mode Integration type PIXel (DIPIX) have been recently produced and described. This report presents initial test results of some of the prototype including tests obtained with the infrared laser beam and Americium (Am-241) source. The Equivalent Noise Charge (ENC) of 85e- has been measured. The measured performance demonstrates that SOI technology is a feasible choice for future applications.Speaker: Mr Mohammed Imran Ahmed (AGH University of Science and Technology, Faculty of Physics and Applied Computer Science)
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The Silicon Vertex Detector of the Belle II ExperimentThe Belle experiment at the KEK-B electron/positron collider in Tsukuba (Japan) has been successfully operating for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2014, aiming a 40-fold peak luminosity compared to the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD). The future Belle II SVD will consist of four layers of double-sided silicon strip sensors (DSSD) entirely made from 6" wafers. Moreover, an inner double-layer pixel detector based on DEPFET technology will complement the SVD as innermost detector and the SVD itself will now contain a slanted forward part. The DSSDs are arranged in the so-called "Origami" chip-on-sensor concept to minimize material budget. This is complemented by a very lightweight mechanical support structure made from carbon fiber reinforced Airex foam and a CO$_2$ cooling system with extremely thin pipes. Since the detector has to operate in an environment with high occupancy and continuous collisions, a hit-time-finding algorithm has been developed to narrow down the effective shaping time of the readout chips to a few nanoseconds. In this talk, an overview of the Belle II SVD design will be given, covering the silicon sensors, the readout system and the lightweight support structures. A strong emphasis will be given to the status of prototype modules and its performance in recent beam tests.Speaker: Dr Thomas Bergauer (HEPHY Vienna)
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Recent developments on CMOS MAPS for the SuperB Silicon Vertex TrackerIn the design of the Silicon Vertex Tracker for the high luminosity SuperB collider, very challenging requirements are set by physics and background conditions on its innermost Layer0: small radius (about 1.5 cm), resolution of 10-15 $\mu$m in both coordinates, low material budget <1% X$_0$, and the ability to withstand a background hit rate of several tens of MHz/cm$^2$. Thanks to an intense R&D program the development of Deep NWell CMOS MAPS (with the ST Microelectronics 130 nm process) has reached a good level of maturity and allowed for the first time the implementation of thin CMOS sensors with similar functionalities as in hybrid pixels, such as pixel-level sparsification and fast time stamping. Further MAPS performance improvements are currently under investigation with two different approaches: the INMAPS CMOS process, featuring a quadruple well and an high resistivity substrate, and 3D CMOS MAPS, realized with vertical integration technology. In both cases specific features of the processes chosen can improve charge collection efficiency, with respect to a standard DNW MAPS design, and allow to implement a more complex in-pixel logic in order to develop a faster readout architecture. Prototypes of MAPS matrix, suitable for application in the SuperB Layer0, have been realized with the INMAPS 180 nm process and the 130 nm Chartered/Tezzaron 3D process and results of their characterization will be presented in this paper.Speaker: Giuliana Rizzo (University of Pisa / INFN)
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LePIX: first results from a novel monolithic pixel sensorWe present an innovative monolithic pixel sensor developed in the framework of the LePIX project aimed at tracking/triggering tasks where high granularity, low power consumption, material budget, radiation hardness and production costs are a concern. The detector is built in a 90nm CMOS process on a substrate of moderate resistivity. This allows charge collection by drift from a depleted region while maintaining the other advantages usually offered by Monolithic Active Pixel Sensors (MAPS), like having a single piece detector and using a standard CMOS production line. The collection by drift mechanism, coupled to the low capacitance design of the collecting node made possible by the monolithic approach, provides an excellent signal to noise ratio straight at the pixel cell together with a radiation tolerance far superior to conventional un-depleted MAPS. We will illustrate the detector design and present measurement results obtained with the first prototypes from laser, radioactive source and beam test experiments. The excellent signal-to-noise performance is demonstrated by the capability of the device to separate the peaks in the spectrum of a Fe-55 source. We will also highlight the interaction between physics goals, pixel cell design and device architecture which all together aim toward a very precise direction in the development of such depleted monolithic pixel devices.Speaker: Dr Serena Mattiazzo (PD)
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Solid State Detectors - Poster Session
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3D-FBK pixel sensors with CMS read-out: first tests resultsSilicon 3D detectors consist of an array of columnar electrodes (radius ∼ 5µm) of both doping types which penetrate entirely in the detector bulk, perpendicularly to the surface. This structure decouples the electrode distance from the sensor substrate thickness. The close electrode spacing provides several advantages compared to the planar sensor design: low full depletion voltage (∼ 10 V), fast charge collection time, reduced charge trapping probability and therefore high radiation hardness. As a result, 3D detectors are emerging as one of the most promising technologies for innermost layers of tracking devices for the foreseen upgrades of the LHC. Until recently, properties of 3D sensors have been investigated mostly with ATLAS readout electronics. 3D pixel sensors compatible with the CMS pixel PSI146 read-out chip were first fabricated at SINTEF (Oslo, Norway), and more recently at FBK (Trento, Italy) and CNM (Barcelona, Spain). Several sensors with different electrode configurations (single n-type electrode (1E), two n-type electrodes (2E), and four n-type electrodes (4E) per pixel cell), all bump-bonded with the CMS pixel PSI46 read-out chip, were characterized in laboratory and tested at Fermilab with a proton beam of 120 GeV/c. Preliminary results of the data analysis will be presented.Speaker: Dr Maria Margherita Obertino (Universita' del Piemonte Orientale)
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A beam radiation monitor based on CVD diamonds for SUPERBCVD diamond particle detectors are presently in use in the CERN experiments ATLAS, CMS, LHCb and ALICE and at particle accelerator laboratories in USA and Japan. This is a proven technology with very fast signal read-out and a very high radiation tolerance suitable for measurements in high radiation environment zones. The properties of CVD diamonds make them a prime candidate for measuring single particles as well as high-intensity particle cascades, for timing measurements on the nanosecond scale and for beam protection systems in hostile environments like regions near the beam pipe. A Polycrystalline CVD and a single-crystalline CVD diamond sensors, read out with a new generation of fast and high bandwidth SiGe bipolar transistor amplifiers, have been tested for possible applications as radiation monitor and as luminometer for the Super-B project. Test results with 5.5 MeV alpha particles from a $^{241}$Am radioactive source and from electrons from a $^{90}$Sr radioactive source are presented.Speaker: Prof. Anna Di Ciaccio (INFN ROMA Tor Vergata and University)
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A quadruple well CMOS MAPS prototype for the Layer0 of the SuperB SVTApsel4well is a chip prototype intended for application to the Layer0 of the SuperB SVT. Physics studies set stringent requirements on the Layer0 design: radius of about 1.5 cm, high granularity (50 μm pixel pitch), fast readout techniques to comply with a high background rate, low material budget and an adequate radiation resistance. The considered approach is based on a planar 180 nm CMOS technology with an additional process step enabling the creation of a buried P-well layer. This deep-Pwell prevents the charge diffusing in the epitaxial layer from being collected by the parasitic Nwell diffusions where PMOS transistors of the readout channel are implemented. In this way, almost the whole amount of charge generated in the epitaxial layer is collected by the Nwell sensors. The ionizing radiation hardness of the device is guaranteed by the adoption of enclosed layout transistors. On the other hand, the use of a 12 μm thick high resistivity epitaxial layer is expected to increase the sensor tolerance to bulk damage. The pixel collecting electrode, consisting of four 1.5x1.5 μm$^2$ interconnected Nwell diodes, is read out by a classical channel for capacitive detectors. The Apsel4well chip consists of several test structures, including single channels, 3x3 pixel matrices and a 32x32 matrix with sparsified readout architecture and time stamping. In the final conference paper, the main design features of the chip and the results from physical device simulations will be presented.Speaker: Dr Stefano Zucca (Università di Pavia)
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Accurate modeling of SiPM detectors coupled to FE electronics for timing performance analysisThe shape of the current pulse produced by a SiPM in response to an incident photon is affected by the characteristics of the FE used to read out the detector. Thus, an accurate modeling of the SiPM is mandatory to identify the best solutions for the architecture and the most relevant design parameters of the FE electronics. When the application requires to approach the best theoretical time performance of the detection system, which calls for high bandwidth and low input resistance FE electronics, the influence of all the parasitics associated to the coupling SiPM – FE can play a relevant role and must be adequately modeled. In particular, it has been reported that the shape of the current pulse is affected by the parasitic inductance of the wiring connection between SiPM and FE. In this contribution, we extend the validity of a previously presented SiPM model to account for the wiring inductance. Analytical expressions of poles and zeroes of the resulting system have been derived, thus allowing to check for the possible presence of a pair of complex conjugate poles, which can produce undesired ringing in the signal waveform. Various combinations of the main performance parameters of the FE electronics (input resistance and bandwidth) have been simulated in order to evaluate their influence on the time accuracy of the detection system, when the time pick-off of each single event is extracted by means of a Leading Edge Discriminator technique.Speaker: Prof. Gianvito Matarrese (DEE - Politecnico di Bari)
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Advanced Alignment of the ATLAS Inner DetectorThe ATLAS detector is equipped with a tracking system (Inner Detector) built using different technologies: silicon planar sensors (pixel and microstrip) and gaseous drift-tubes, all embedded in a 2T solenoidal field. Quality tracking requires to determine its almost 700,000 geometrical degrees of freedom (DoF) with high accuracy. ATLAS physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on systematic effects related to alignment of the tracking system. ID alignment is based on the official tracking event data model of ATLAS which allows for the full integration into the official tracking realm. In order to eliminate malicious systematic deformations, various advanced tools and techniques have been put in place. These include information from known mass resonances, energy of electrons and positrons measured by the electromagnetic calorimeters, beam-spot and primary vertex constrains, etc. Alignment algorithms are complemented by the extended online and offline monitoring scheme. An outline of the track based alignment approaches and their implementation within the ATLAS software will be presented. Special attention will be paid to techniques allowing to identify and eliminate tracking systematics. Results from the 2011 LHC proton-proton collision runs at 7 TeV will be reviewed and performance improvement discussed.Speaker: Mr Jonathan Stahlman (University of Pennsylvania)
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ATLAS Silicon Microstrip Tracker Operation and PerformanceThe Semi-Conductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices in the Inner Detector of the ATLAS experiment at CERN LHC. In the talk the current status of the SCT will be reviewed. We will report on the operation of the detector including an overview of the issues we encountered and the observation of significant increases in leakage currents (as expected) from bulk damage due to non-ionising radiation. The main emphasis will be given to the tracking performance of the SCT and the data quality during the many months of data taking (the LHC delivered 47pb$^{-1}$ in 2010 and 5.6fb$^{-1}$ in 2011 of proton-proton collision data at 7 TeV, and two times one-month periods of heavy ion collisions). The SCT has been fully operational throughout all data taking periods. It delivered high quality tracking data for 99.9% (2010) and 99.6% (2011) of the delivered luminosity. The SCT running experience will then be used to extract valuable lessons for future silicon strip detector projects.Speaker: Peter Lundgaard Rosendahl (University of Bergen (NO))
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Beam Conditions Monitoring in ATLASBeam conditions and the potential detector damage resulting from their anomalies have pushed the LHC experiments to build their own beam monitoring devices. The ATLAS Experiment decided to build two independent systems based on Chemical Vapor Deposition (CVD) diamond material. The ATLAS Beam Conditions Monitor (BCM) consists of two stations (forward and backward) of detectors each with four modules. The sensors are required to tolerate doses up to 500 kGy and in excess of 10$^{15}$ charged particles per cm$^2$ over the lifetime of the experiment. The BCM has operated reliably in ATLAS for the last 24 months, has provided feedback on every beam dump during that time and is required to show a clean abort before ATLAS returns the LHC injection permit. In addition the BCM provides collision rate and background measurements that have been instrumental in ATLAS achieving a luminosity precision of better than 4%. As luminosity reached unprecedented levels in 2011 and other luminosity monitors in ATLAS reached saturation, ATLAS reported luminosity comes from BCM measurements. For the ATLAS Beam Loss Monitor (BLM) a simpler detector was installed. There are 12 sensors, 6 on each side of ATLAS Inner Detector. The readout electronics is based on LHC BLM systems. ATLAS BLM justifiably aborted the LHC beams twice in Summer 2011 which prevented possible damage to the Inner Detector. The performance of the BCM and BLM detectors and their contributions to ATLAS physics will be presented.Speaker: Dr Andrej Gorisek (J. Stefan Institute, Ljubljana)
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Beam test results for the SuperB SVT thin striplet detectorThe SuperB Silicon Vertex Tracker will be made of 5 layers of double sided silicon strip sensors plus an additional innermost layer (Layer0) at a radius of about 1.5 cm, very close to the beam pipe. For the first phase of the experiment the baseline option for the Layer0 is a high resistivity thin (200 $\mu$m) double sided silicon detector, with short strips ("Striplets") at 45° angle to the detector's edge. This design allows lower material budget compared to standard strip detectors. Moreover, the strips are shorter than in standard designs; this reduces the average occupancy per channel and compensates for the increased strip-to-back capacity. In September 2011 Striplets were tested in a 120 GeV/c pion beam at the CERN SPS. In the following we present the beam test results on striplet sensors readout by the FSSR2 chip, the second release of the Fermilab Silicon Strip Readout chip, originally designed for the silicon strip detectors of the BTeV experiment. We report here experimental results on efficiency and spatial resolution achieved as a function of the incidence angle up to 70°.Speaker: Laura Fabbri (INFN - Bologna)
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Calibration of a pixel sensor using both fluorescence and transmitted X-ray photonsPixel sensors have been calibrated using both fluorescence X-ray photons and a narrow X-ray beam obtained by transmission technique. The X-rays were generated by a Amptek EDIX 40 X-ray tube (Maximum voltage 40 kV). During the fluorescence calibration the pixel sensor was placed in front of the target in a off-beam position, the resulting photons hitting the detector were emitted by fluorescence in all directions with an energy which is typical of the fluorescence lines of the target material. During the calibration in transmission mode the detector was placed behind the target, acting now as a filter, and the energy of the photons is tuned by adjusting the voltage of the tube and the thickness of the target. In this poster presentation the comparison between the two methods will be shown. From the results of this test, it is possible to infer that transmission is more efficient (higher photon yield) and flexible (more energy points are possible) but produces broader lines while fluorescence has a better energy definition. A reasonable strategy to benefit from both methods is using fluorescence to calibrate a spectrometer that will be used to evaluate the energy of the X-rays emitted in transmission mode. The results of this calibration will be shown in the poster.Speaker: Dr Mauro Menichelli (INFN Sez. di Perugia)
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Characterization of CVD-diamonds for radiation detectionWe report for several tests carried on Chemical Vapour Deposition (CVD) diamonds to be used as ionizing radiation detectors. The unique properties of diamond makes it one of the most promising wide band-gap materials not only in the already established field of high luminosity X-ray detection for medical applications but also in modern high energy physics. CVD diamonds can be built in two different structures: polycrystalline with crystal size about 10-30% of thickness of grown samples, and single crystal. The production of sufficiently cheap diamond specimen with size of at least 5 mm diameter and thickness 50-1000 m with sufficient quality to tackle the requirements of detector applications is a hot technological challenge. Recent progress in growth of diamond samples of very high purity and high homogeneity along all their volume has opened perspectives to a new type of UV photosensors in order to work with large volume two phase liquid-Ar and/or liquid-Xe detectors, nowadays under design for next generation dark matter search. CVD diamond samples of both crystalline structures, supplied by Brevetti Bizz firm of San Bonifacio (VR, Italy) were investigated and the results of Current-Voltage characteristics, charge collection investigations for holes and electrons, and SEM/EDS analysis, in order to known the kind and the concentration of lattice impurities, are presented and discussed.Speaker: Dr Gianpiero Gervino (Dipartimento di Fisica and INFN Torino)
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Characterization of Strip Detector Parameters for the SuperB SVTThe Silicon Vertex Tracker for the SuperB detector will be an evolution of the BaBar SVT, based on double-sided strip detectors. The wider acceptance in polar angle (down to 300 mr) will entail larger incidence angles (up to 73 degrees) on the sensors and a larger number of z-side strips. For optimum performance it would be desirable to continuously vary the sensor pitch on z-side versus position. An easy and convenient way to approximate this configuration is to bond two or three adjacent strips to a single trace of the fanout circuit that connects the strips to the front-end electronics (`pairing’ option). In order to accurately measure the total capacitance of strips in various pairing configurations (x2, x3, x4) a test detector has been assembled on a PCB and various strip connection schemes have been implemented by wire bonding, both on p and on n-sides. Capacitance and dissipation factor have been measured versus bias voltage and frequency. In addition, noise measurements versus shaping time are being performed, using a single-channel readout chain. These data will be used to estimate the noise contribution of the detector and to choose the best connection scheme in the SVT. Capacitance and noise measurements made on prototypes of the striplet detectors that are planned to equip the innermost layer of the SVT will also be reported.Speaker: Dr Irina Rashevskaya (INFN – Sezione di Trieste)
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CMS Tracker PerformanceThe CMS silicon pixel and strip tracker is at the core of every physics analysis in CMS. We present its performance during the first three years of LHC data taking. From the monitoring of its basic observables to the vertexing and tracking performance at analysis level we give a broad overview of the tracker's behavior. Special focus will be put on the dependence of its performance on the increasing pileup conditions as the beam parameters in the LHC get more and more intense. We also present the alignment algorithm, which has about 200,000 free parameters and allows for movement of the large and small structures as well as bows and kinks down to sensor level, and which has been fine tuned and adapted to the high precision needs of the CMS physics programme.Speaker: Dr Petra Merkel (Purdue University)
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Comparative Characterization of Pixel Detectors at Very High Fluences - Diamond versus SiliconMeasurements on irradiated diamond pixel detectors (poly-crystalline and single crystal) equipped with the ATLAS FE-I4 pixel readout chip are confronted with similar silicon pixel detectors regarding their performance at high radiation fluences as expected at an HL-LHC. Within the competition of CVD diamond detectors with silicon the question of the expected S/N – ratio (SNR) after irradiation has been an issue ever since. While before radiation damage silicon yields a larger signal due to the much smaller band gap at similar noise levels, this situation changes in environments in which fluences in excess of $\approx 10^{15}$ neq/cm$^2$ are expected. Diamond is attractive because of its tiny leakage current even after irradiation and its smaller capacitance both rendering lower noise. We present measurements on irradiated poly- and mono-crystalline pixel sensors in comparison with silicon pixel devices, equipped with the FE-I4 chip. The noise for both diamond and silicon detectors is determined by a full transient noise analysis and by measuring the different pixel capacitances with a dedicated chip (PixCap). The simulations are compared with measurements. The comparison is finally completed by predicting the signal an the leakage current at a given fluence and dividing by the noise. The result is the signal to noise ratio for a given fluence for diamond and planar silicon pixel detectors.Speaker: Prof. Norbert Wermes (University of Bonn)
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Computer Simulation of Contacts on CdZnTeThe issue of contacts to high resistivity semiconductors in general and to II-VI group, in particular, has always been a great challenge. Such is the case for semiconductor radiation detectors based on CdTe and Cd1-xZnxTe. Interpretation of experimental results is always based on some physical model of the device. Thus, incorrect modeling is bound to lead to misleading conclusions. In modeling of high resistivity semiconductor devices, particularly wide-bandgap, special care must be taken, since many classical, “textbook” assumptions are not valid. In this work Cd0.9Zn0.1Te devices with various contacts are calculated using finite element computer program. The influences of velocity saturation, generation-recombination and deep levels on the energy band structure and device characteristics are discussed.Speaker: Prof. Arie Ruzin (Tel Aviv University)
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Development of thin pixel detectors on epitaxial silicon for HEP experimentsThe foreseen luminosity of the new experiments in High Energy Physics will require that the next generation of vertex detectors will be able to sustain fluencies up to $1\times10^{16}$ cm$^{−2}$. Moreover, in many experiments there is a demand for the minimization of the material budget of the detectors. Therefore, thin pixel devices on epitaxial material are a natural choice to fulfill these requirements due to their rad-hard performances and low active volume. We present an R&D activity aimed at developing a new thin hybrid pixel device in the framework of PANDA experiments. The detector is a p-on-n pixel sensor realized starting from epitaxial silicon wafers, in which the sensitive area is the epi-layer itself, while the low-resistivity substrate acts as a mechanical support. After completion of the fabrication, the substrate is back thinned down to a value slightly larger than the epitaxial layer thickness, which can be in the order of 50-100 microns. We present the main technological steps and some electrical characterization of the fabricated devices before and after back thinning and after bump bonding to the FE electronics.Speaker: Mr Maurizio Boscardin (FBK)
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Energy and Timing resolution of FBK SiPMs coupled to PETA3 read-out ASICIn the framework of the HyperImage and Sublima EU projects we are developing a SiPM-based high-performance TOF-PET system to be integrated in a MRI. It has already been shown that single-element FBK SiPMs coupled to LYSO scintillator and read out by an optimized discrete circuit provide excellent energy and timing information. In this paper we demonstrate that a very good performance can be reached also in a system-like configuration. The new set-up is based on the PETA3 read-out ASIC, developed by the University of Heidelberg. The interconnection scheme (ASIC board and connectors to sensor) is identical to the one used in the PET module developed for the above-mentioned projects. The system performance is evaluated by measuring the energy resolution and the coincidence resolving time (CRT) of two single SiPMs coupled to LYSO crystals and read out by two channels of the ASIC. As an example, using two scintillator detectors, composed of a 3x3x15 mm$^3$ LYSO crystal coupled to a 3x3 mm$^2$ SiPM, a CRT of 250 ps FWHM can be obtained. The best value we measured with the optimized discrete read-out configuration was 220 ps. Details about the set-up as well as the results will be given at the conference.Speaker: Dr Claudio Piemonte (Fondazione Bruno Kessler)
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First results on NUV-SiPMs at FBKIn this contribution we show selected results on the first release of UV-enhanced SiPM technology (NUV-SiPM) produced at FBK. In particular, we focus our attention on the photo-detection efficiency (PDE) performance. The PDE in the near-UV part of the light spectrum is mainly limited by the quantum efficiency term since the photo-generation takes place in a very shallow region of the silicon. Thus, besides using a p$^+$-on-n junction configuration to have an avalanche triggered by the electrons, we need to implement a very shallow p$^+$ layer. In this context, we will show that our NUV-SiPM technology features a quantum efficiency higher than 80% in the measured range between 360 nm and 420 nm. This allows to reach a PDE of 30% at 9 V over-voltage with a device featuring 50x50 $\mu$m$^2$ cell size and 45% fill factor. We will also show other important features of the device such as breakdown voltage temperature dependence, single-cell response uniformity and noise.Speaker: Dr Alessandro Tarolli (Fondazione Bruno Kessler)
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Functional characterization of planar sensors with active edges using laser and X-Ray beam scansIn the framework of our R&D activities oriented to 3D detectors, which finally led to the first production for the ATLAS Insertable B layer, we have also developed planar sensors with active edge. First proposed by C. Kenney et al., this type of edge termination consists of a deep trench etched all around the active area and doped as an ohmic electrode. One batch of these devices was fabricated at Fondazione Bruno Kessler, Trento, Italy, and was split into two parts. From the characterization of the first part, it was possible to understand some critical features and to improve the fabrication process, so that devices from the second part had better defined trenches and good electrical characteristics in terms of breakdown voltage. At the conference we will report on the functional characterization of test diodes with active-edges performed by means of 1060nm laser scans carried out in our lab and by means of 15keV X-Ray beam scans carried out at the Diamond light source, UK. Measurements were performed on devices featuring different distances between the active area and the trench. Thanks to these measurements it was possible to investigate the effects of the bias voltage on the signal efficiency of the edge region (in particular the corner region) with different radiation sources and to demonstrate that devices work as expected. Preliminary results are very promising showing a full efficiency of the devices just ~20μm away from the physical edge.Speaker: Mr Marco Povoli (Università di Trento/INFN)
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Functional test of a Radon sensor based on a high-resistivity-silicon BJT detectorA battery-powered, wireless Radon sensor has been designed and realized using a Bipolar Junction Transistor a radiation detector fabricated on a high-resistivity-silicon substrate. Radon daughters are collected on the detector surface electrostatically. Thanks to the BJT excellent signal-to-noise ratio and internal amplification, real-time alpha particle detection is possible using a simple readout electronics, which records the alpha particle arrival time and charge spectrum. Readout is based on a commercial chip, providing charge integration and 20-bit A/D conversion, coupled to a microcontroller. The system can keep trace of particle arrival times thanks to a real-time clock . Since WSN (Wireless Sensor Network) is of great appeal for wide-area monitoring, environmental tests and also for building measurements, the readout system was provided with wireless communication capabilities suitable for star-arranged networks (single-point-to-multi-point). The RF module implements a communication system based on a commercial standard, offering advantages in terms of a simple interface with the MSP430-family controllers, low development costs and low power consumption. Functional tests have been carried out in a Radon camera using Autumnite stones as a Radon source), and an AlphaGUARD Radon Monitor as a reference sensor. Tests demonstrated a good sensitivity of 0.7-1.2 CPH/(100 Bq/m$^3$) and the capability to perform alpha spectroscopy of Radon daughters.Speaker: Prof. Gian-Franco Dalla Betta (University of Trento and INFN and RSENS)
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Hybrid diamond pixel detectors for the upgrade of ATLASChemical Vapour Deposition (CVD) diamond has a number of properties that make it an attractive alternative for high energy physics detector applications like tracking detectors, luminosity monitors and beam monitors. Its large band-gap (5.5 eV) and large displacement energy (42 eV/atom) make it a material that is inherently radiation tolerant with very low leakage currents and high thermal conductivity. CVD diamond is being investigated by the RD42 Collaboration for use very close to LHC interaction regions, where the most extreme radiation conditions are found and thus hybrid pixel detectors are used. A process of building pixel modules with CVD diamond detectors has been developed together with the Fraunhofer IZM, the bump vendor of ATLAS IBL. As readout chip FE-I4, the new ATLAS pixel chip is used. FE-I4 features 80x336 pixel on a 20x16.8 mm$^2$ active area and 25 ns time resolution which can be operated at thresholds below 1500e-. Results show that the low threshold of FE-I4 together with the low noise of the diamond is the key feature for their operation. Recently the FE-I4 diamond pixel modules have been chosen for the ATLAS Diamond Beam Monitor project (DBM), an upgrade of the ATLAS luminosity measurements system. In this presentation the production process of diamond pixel detectors is explained and the results of FE-I4 based pixel modules in test beam and lab measurement are presented. The usage of diamond pixel detectors in the upgrade projects of ATLAS is discussed.Speaker: Dr Fabian Huegging (University of Bonn)
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Interpolating Silicon PhotomultipliersWe present the novel {\bf I}nterpolating {\bf Si}licon {\bf P}hoto{\bf M}ultiplier (ISiPM) topology which provides the spatial position of photon clusters with high resolution. Individual APD cells of the ISiPM area are not connected to a {\em common} readout electrode, but each cell is connected to {\em one of several} output channels. The most straight forward embodiment is a rectangular device with four outputs located (conceptually) in the corners. The assignment of each cell to one of the channels is chosen such that the center of gravity of an arbitrarily shaped group of cells can be reconstructed as (for instance) the weighted sum of the corner signals. Due to the finite size of the cells, this exact goal can only be approximated and residual systematical errors remain. An algorithm is presented which produces fractal assignment maps with homogeneous reconstruction properties. Simulated limits of the expected spatial resolution as a function of cell size, cluster size, number of fired cells per cluster and readout noise will be presented. A first prototype device with {$100\times100$} cells on a total size of $7.5\times7.4\,\mathrm{mm}^2$ has been fabricated at FBK and operated successfully. Individual LYSO crystals of $\approx 2\,\mathrm{mm}$ width in a block array can be identified. The ISiPM concept offers good spatial resolution on large areas with a moderate number of readout channels so that it is a promising device for instance for PET detectors.Speaker: Prof. Peter Fischer (Heidelberg University)
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Monitoring radiation damage in the ATLAS Pixel DetectorThe record breaking instantaneous luminosities of $10^{33} cm^{-2} s^{-1}$ recently surpassed at the Large Hadron Collider generate a rapidly increasing particle fluence in the ATLAS Pixel Detector. As the radiation dose accumulates, the first effects of radiation damage are now observable in the silicon sensors. A regular monitoring program has been conducted and reveals an increase in the silicon leakage current, which is found to be correlated with the rising radiation dose recorded by independent sensors within the inner detector volume. Such measurements are useful to validate the digitization model that has been developed to simulate radiation damage effects, including charge trapping, electric field modification and realistic signal induction on the electrodes. In the longer-term crystal defect formation in the silicon bulk is expected to alter the effective doping concentration, producing type-inversion and ultimately an increase of the voltage required to fully deplete the sensor.Speaker: Dr Mark Cooke (LBNL)
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Neural network based cluster creation in the ATLAS silicon pixel detectorThe read-out from individual pixels on planar semi-conductor sensors are grouped into clusters to reconstruct the location where a charged particle passed through the sensor. The resolution given by individual pixel sizes is significantly improved by using the information from the charge sharing between pixels. Such analog cluster creation techniques have been used for many years to obtain an excellent performance. However, in dense environments, such as those inside high-energy jets, clusters have an increased probability of merging the charge deposited by multiple particles. Recently, a neural network based algorithm which estimates both the cluster position and whether a cluster should be split has been developed for the ATLAS pixel detector. The algorithm significantly reduces ambiguities in the assignment of pixel detector measurement to tracks within jets and improves the position accuracy with respect to standard interpolation techniques by taking into account the 2-dimensional charge distribution. The implementation of the neural network, the training parameters and performance of the new clustering will be presented. Significant improvements of the track and vertex resolution obtained using this new method will be presented using Monte Carlo simulated data and compared to data recorded with the ATLAS detector will be given. The resulting improvements to both track reconstruction and the identification of jets containing b-quarks will be discussed.Speaker: Ms Karoline Selbach (University of Edinburgh)
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Novel 3D micro-structuring of diamond for radiation detector applications: enhanced performances evaluated under particles and photons beams.In order to push forward the state-of-the art of device radiation hardness, we propose to use so called 3D electrode geometry: where the collecting electrodes are implemented within the bulk of the diamond and separated by a few tens of microns (limited by the processing techniques). The reduced distance between the buried electrodes enables higher electric fields to be applied, thus faster drift velocities, shorter drift path of charge carriers, and a reduced probability of trapping in the detector. Such an approach has been successfully tested for silicon detectors where significant improvement in radiation hardness (comparable to planar diamond detectors) has been obtained. Here we applied the approach to diamond devices, processing 3D geometries to demonstrate the gain it brings to the performances of CVD diamond detectors. The prototypes used buried conductive graphitic micro-channels, fabricated within the diamond bulk using an UV laser (337 nm). A 5x5 matrix with 200µm spacing between electrodes was processed on a mono-crystalline sample. The electronic properties of the 3D diamond prototype were carefully evaluated, including namely current-voltage, transient-current, and charge collection efficiency characteristics under ionizing particles and X-ray micro-beam. The results demonstrate the improvements provided by the 3D diamond detectors and open up new possibilities for radiation detectors for extreme applications.Speaker: Mr Benoît Caylar (CEA-LIST, Diamond Sensor Laboratory)
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Novel Silicon n-in-p Pixel Sensors for the future ATLAS UpgradesIn view of the LHC upgrade phases towards HL-LHC the ATLAS experiment plans to upgrade the Inner Detector with an all silicon system.\\ The n-in-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors.\\ We present the characterization and performance of novel n-in-p planar pixel sensors produced by CiS (Germany) connected by bump bonding to the ATLAS readout chip FE-I3.\\ These results are obtained before and after irradiation up to a fluence of $1\times10^{16}\,n_{eq}cm^{-2}$. Charge collection and tracking efficiency studies have proven the functioning of this technology up to this fluence.\\ It will be also presented an overview of the new pixel production, which is on-going at CiS for sensors compatible with the new ATLAS readout chip FE-I4 and featuring reduced thickness down to 150\,$\mu$m. These sensors will be used to investigate the radiation hardness of thinner detectors at HL-LHC fluences.\\Speaker: Alessandro La Rosa (DPNC, Université de Geneve)
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Overview and development progress of the Silicon Tracking System for the CBM experimentThe goal of the Compressed Baryonic Matter~(CBM) experiment is study the phase diagram of strongly interacting matter at high baryonic densities. It is going to be done by colliding proton and heavy ion beams of energy up to 35~AGeV with fixed carbon and heavy element targets. The physics program of the experiment requires to reconstruct all charged products, measure their momenta with high resolution, accurately identify charged hadrons, muons and espcecially electrons, detect neutral hardons and photons and measure their energy. The charged multiplicity is expected to come up to 1000 per central Au-Au collisions which necessitates high detector granularity. The experiment is going to run at high interaction rates: $10^6$~$s^{-1}$ for Au-Au collisions and $10^7$~s$^{-1}$ for p-C collisions, and self-triggered read-out electronics will be used. The key element of the planned detector setup is the Silicon Tracking System, which will be based on double-sided p-in-n silicon strip detectors with 50~$\mu$m pitch and~300 $\mu$m thickness. It has to enable momentum resolution of 1~$\%$, time resolution of about few nanoseconds, and stand up to $3\cdot10^{13}$ neutron equivalent dose. The CBM Silicon Tracking System design is presented as well as the current progress in it's development.Speaker: Mr Iurii Sorokin (Goethe University Frankfurt)
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Performance of the LHCb VELOLHCb is a dedicated experiment to study new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and offline physics analyses. The VELO is the highest resolution vertex detector at the LHC. The VELO is the silicon detector surrounding the LHCb interaction point, and is located only 7 mm from the LHC beam during normal operation. The VELO is moved into position for each fill of the LHC, once stable beams are obtained. The detector is centred around the LHC beam during the insertion by the online reconstruction of the primary vertex position. The VELO consists of two retractable detector halves with 21 silicon micro-strip tracking modules each. A module is composed of two n$^+$-on-n 300 micron thick half disc sensors with R-measuring and Phi-measuring micro-strip geometry, mounted on a carbon fibre support paddle. The minimum pitch is approximately 40 µm. The detectors are operated in vacuum and a bi-phase C0$_2$ cooling system used. The detectors are readout with an analogue front-end chip and the signals processed by a set of algorithms in FPGA processing boards. The VELO has been successfully operated for the first LHC physics runs. Operational results show a signal to noise ratio of around 20:1 and a best hit resolution of 4 microns.Speaker: Mr David Dossett (University of Warwick)
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Planar Pixel Sensors for the ATLAS tracker upgrade at HL-LHCThe ATLAS Planar Pixel Sensor (PPS) R&D Project is a collaboration of 17 institutes and more than 80 scientists, started to explore the feasibility of employing planar pixel sensors for the upgraded tracker at HL-LHC. Different pixel concepts are investigated for the inner and outer layers. In the first case the focus is on extreme radiation hardness, with the use of very thin pixel sensors (with an active thickness in the range of 75-150 $\mu$m), and the achievement of slim and active edges to provide low geometrical inefficiency. In the case of the outer layers, different approaches are being investigated to face the challenge of instrumenting an increased surface with respect to the present pixel system: production on 6” instead of 4" wafers, more cost-efficient and industrialised interconnection techniques and establishing the n-in-p technology which as a single-sided process requires less production steps. New results will be presented, illustrating the performance of FE-I3 and FE-I4 pixel modules, irradiated up to a fluence of $2\times10^{16}\,n_{eq}/cm^{2}$ . The focus will be on charge collection and noise measurements performed with radioactive sources in the laboratory and tracking efficiencies of the different planar technologies extracted from beam tests with pions at CERN SPS. With these studies tracking efficiencies of 97% after a fluence of $2\times10^{16}\,n_{eq}/cm^{2}$ have been demonstrated with n-in-n FE-I3 modules as well as efficiencies of 98-99% at a fluence of $5\times10^{15}\,n_{eq}/cm^{2}$ for n-in-p modules.Speaker: Mr Christian Gallrapp (CERN)
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Radiation Damage Effects in LHCb VELO OperationsThe VELO is the silicon detector surrounding the LHCb interaction point. The sensors have an inner radius of only 7mm from the LHC beam and an outer radius of 42 mm. Consequently the sensors receive a large and non-uniform radiation dose. A dose of $0.5\times10^{13}$ 1 MeV neutron equivalents /cm$^2$ per fb$^{-1}$ of data is predicted at the tip of the sensors. The sensors are fabricated from oxygenated n-on-n silicon with one module made from n-on-p silicon, the only n-on-p module operated at the LHC. LHCb is a dedicated experiment to study new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO). The VELO is the highest resolution vertex detector at the LHC. The radiation damage is monitored by three studies: 1) the currents drawn as a function of temperature and voltage 2) studying the noise versus voltage behaviour and 3) charge collection efficiency, studied with tracks from proton-proton collisions, as a function of voltage. The results of all three studies are presented. Clear differences in behaviour, as expected, are observed between n-on-n and n-on-p sensors. Type inversion is observed in the n-in-n sensors. The p-type sensors depletion voltage first reduced and is now increasing. Radiation induced charge loss due to the second metal layer on the sensors is also observed and will be discussed.Speaker: Mr David Dossett (University of Warwick)
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Radiation tolerance of a moderate resistivity substrate in a modern CMOS processThe LePix project aims at developing monolithic detectors integrating reverse biased detecting diodes and readout circuitry in 90 nm CMOS. In this framework we are investigating the radiation tolerance of the base material, which is an order of magnitude more doped than standard high resistivity detectors, and which underwent the full advanced CMOS process. This investigation is carried out on diodes of about one square mm, of which samples were irradiated with neutrons at fluences from $10^{12}$ to $10^{16}$ neutrons per square cm. The irradiated devices were characterized using CV, IV, and pulsed laser measurements. Other than diodes, we also have irradiated pixel matrices up to same fluences, and we started to characterize them. These matrices were already irradiatied with Xrays, and we were able to prove they withstand at least 10 Mrad. We will show the measurement results and draw conclusions.Speaker: Mr Alberto Potenza (Torino University)
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Resistant, Sensitive and Fast CVD Diamond Detectors for Intense Ionizing RadiationSeveral medical applications rely on the interaction between high-energy radiation and human tissue. Radiotherapy, radiography, and mammography as well as high-energy physics experiments need a very precise measurement of the radiation dose imparted to the target volume. These techniques differ in the radiation energy content, but all of them require reliable, precise, and sensitive detectors to accurately calibrate the radiation sources and/or directly monitor the dose delivered to a patient. CVD diamond is a suitable material to be used for intense x-ray and gamma dosimetry since it shows properties of tissue equivalence, radiation hardness and chemical inertness. Such characteristics imply no energy corrections respect to human tissue and advantages of long operative lifetimes. X-ray diamond dosimeters were assembled by developing injecting diamond-like-carbon/Pt/Au contacts on single-crystal high-purity diamond films with the aim to reduce space-charge effects. Resistivity in the dark of (5.6±0.1)×1014 Ω cm was measured as well as low density deep-states in the band-gap were evaluated from spectrally resolved photoconductivity measurements. Devices resulted to be priming-less with a linearity coefficient to x-ray (Mo-K) dose-rate of 1.02±0.01. Transient x-ray modulated analysis allowed the determination of fast traps influence and an estimation of the dosimeters response times, very fast (10-3 s) at high fields (≥3×10-3 V/cm)Speaker: Dr Daniele M. Trucchi (CNR-IMIP)
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Silicon buried channels for Pixel detector coolingThe support and cooling structures add an important contribution to the total material of vertex detectors. In order to minimize the material budget of pixel sensors, we developed a new approach to integrate the cooling - into the silicon devices – based on the microchannel technology. The microchannels are formed in silicon using isotropic SF6 plasma etching in a DRIE (deep reactive ion etcher) equipment. Due to their peculiar profiles, the channels can be sealed by a layer of a PECVD silicon oxide. We have realized on a silicon wafer microchannels with different geometries and hydraulic diameters. We describe the main fabrication steps of microchannels with focus on the channel definition. We report the experimental results on the thermal characterization of several prototypes, using a mixture of glycol and water as a liquid coolant. The prototypes have shown high cooling efficiency and high-pressure breaking strength.Speaker: Mr Maurizio Boscardin (FBK)
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Silicon sensor alliance: radiation detector development for the LHC upgradeSilicon Sensor Alliance (SSA) gathers European institutes together to answer for the large need of silicon sensors for CERN’s LHC upgrade. Currently more than 90% of the LHC’s sensors were fabricated outside European countries. The aim of the SSA is to be a qualified and reliable union in Europe to manufacture and provide uniform and high quality radiation detectors to meet the requirement of LHC upgrade. The partners participating in the first fabrication demonstration are VTT (Finland), CiS (Germany), FBK (Italy), CNM (Spain), Acreo (Sweden). The wafer material is selected to be n-type MCz silicon with crystal orientation <100>. To be ready and successful in the first market survey of CERN, it is necessary that all participants are able to provide uniform sensor quality at different foundries and have a reference of this result. It is the first time that a number of SSA partners have initialized a joint demonstration to fabricate radiation hard AC-coupled silicon sensors at different European foundries and planned unbiased testing of them to obtain reference and publicity among the LHC’s experiments. The presentation introduces the SSA sensor fabrication at VTT and its electrical characterization. The comparison curves will be made with available results from other SSA partners to evaluate fabrication uniformity. The presentation will include TCAD simulation and beam test results, if they are ready before the meeting.Speaker: Mr Xiaopeng Wu (VTT)
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Status and Performance of the Diamond-Pixel Based CMS PLT Luminosity MonitorThe Pixel Luminosity Telescope (PLT) is a compact single-crystal diamond pixel based tracking detector. The PLT is designed to measure both the instantaneous luminosity and the relative bunch-to-bunch luminosity with high precision and speed at CMS at the much higher instantaneous luminosities the LHC will provide starting in 2015. One quarter of the full detector has been installed in a forward region of CMS as a preliminary test during the 2012 running. We will show the design capabilities of the PLT as well as results from recent test beams and from LHC collision data.Speaker: Dr Dean Andrew Hidas (Rutgers/CERN)
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Status of the ATLAS Pixel Detector at the LHC and its performance after three years of operation.The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this talk, results from the successful operation of the Pixel Detector at the LHC and its status after three years of operation will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: ~97 % of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, and a good alignment allows high quality track resolution.Speaker: Dr Andrea Favareto (INFN - Milano)
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Test-beam studies of diamond sensors for SLHCDiamond sensors are studied as an alternative to silicon sensors to withstand the high radiation doses that are expected in future upgrades of the pixel detectors for the SLHC. Diamond pixel sensors are intrinsically radiation hard and are considered as a possible solution for the innermost tracker layers close to the interaction point where current silicon sensors cannot cope with the harsh radiation environment. An effort to study possible candidates for the upgrades is undergoing using the Fermilab test-beam facility, FTBF, where diamonds and 3D silicon sensors have been studied. Using a CMS pixel-based telescope built and installed at the FTBF facility we are studying charge collection efficiencies for unirradiated and irradiated devices bump-bonded to the CMS PSI46 pixel readout chip. A description of the test-beam effort and preliminary results on diamond sensors will be presented.Speaker: Dr Lorenzo Uplegger (Fermilab)
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The CMS Tracker Alignment in p-p CollisionsThe CMS all-silicon tracker consists of 16588 modules. Aligning these with the desired precision of a few micrometers is only feasable using track based alignment procedures. Ultimate local precision is now achieved by the determination of sensor curvatures. This faces the algorithms with about 200k parameters to be calculated simultaneously. This can be well handled using the Millepede II program interfaced with CMS software. The main remaining challenge are systematic distortions in the achieved geometry that are systematically biasing the track parameters like the track momenta. These distortions are controlled by adding further information into the alignment workflow, e.g. the mass of decaying resonances. The orientation of the tracker with respect to the magnetic field of CMS is determined with a stand-alone chi-square minimization procedure. The geometries are finally carefully validated. The monitored quantities include the basic track quantities for tracks from both collisions and cosmic muons and physics observables like resonace masses.Speaker: Dr Ashutosh Bhardwaj (University of Delhi)
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The DEPFET Active Pixels for Belle II - Resolution in 50 micron Thinned SensorDetectors for experiments at future colliders – e.g. the Super B-factories or the ILC – require excellent vertexing performance for the layers close to primary interaction region. These detectors need to enable excellent vertex reconstruction, achievable by a highly granular pixel detector, together with fast readout and minimum material budget to reduce the impact on the measurement due to multiple Coulomb scattering. The latter requirement severely constrains the sensor thickness, power consumption, and the design of the detector services. The DEPFET technology of active pixel sensors is among the frontier detector concepts for high energy physics at high luminosities. It has been chosen by the new Belle II experiment for the SuperKEKB collider at KEK. In-pixel amplification enables to use very thin low noise sensors. The frontend electronics and the data acquisition concepts supporting the integration into Belle II are finalized and the two-layer detector (PXD) will be ready for acquiring data from 7.6 million pixels in 2015. The operating principle of the PXD with its expected performance in Belle II will be presented, focusing on the resolution properties of the planned 75 micron sensor. First successful tests in pion beams at CERN with prototype DEPFET pixel matrices, thinned down to 50 microns, show that the target resolution requirements are met. These results will be presented, together with a detailed analysis of the in-pixel resolution distributions.Speaker: Peter Kodys (Charles University)
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The micro-cooled light support of the pixel modules for the Super-B experimentPixel detectors require that high power density in the sensitive area should be carried away by thermal systems, eventually integrated in the light mechanical support structures. The micro-channel cooling technology is characterized by a highly efficient thermal exchange. It can profit of the miniaturization techniques employed on composite materials, allowing important advantage in terms of material reduction. We present the design of the mechanical supports for the pixel layer of the Super-B Silicon Vertex Tracker, using micro-channel cooling technology through forced convection. The thermal tests of the prototypes for a dissipated power of 2 W/cm$^2$, supplied with a liquid coolant at 10°C, have shown that the sensor remains below the operating temperature with material thickness of 0.11 % X$_0$. FEA simulations, structural and thermo hydraulic characterizations are reported.Speaker: Mr Filippo Bosi (INFN Pisa)
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The Micro-Vertex-Detector of the CBM-ExperimentThe Compressed Baryonic Matter Experiment (CBM) is one of the core experiments of the future FAIR facility at Darmstadt/Germany. The experiment will explore the phase diagram of hadronic matter in the regime of highest baryon densities. Nuclear fireballs created in heavy ion collisions of 8-45 AGeV beam energy will be studied with numerous probes, among them open charm. Reconstructing those rare probes requires a vacuum compatible micro vertex detector (MVD) with unprecedented properties. Its sensor technology has to feature a spatial resolution of <5µm, a radiation tolerance of >$10^{13}$ n/cm² and a time resolution of few 10 µs. The detector station must combine an active cooling of the sensors (~1W/cm²) with a material budget below few 0.1% radiation length. To match those requirements, we rely on the CMOS Monolithic Active Pixel Sensors provided by the IPHC Strasbourg. The highly granular and 50µm thin sensors will be mounted on a cooling support made from CVD diamond. This support drives the dissipated power to a heat sink outside the detector acceptance. Moreover, ultra-thin flex print cables are employed to supply power and to connect the sensors to the readout and slow control We discuss the concept of the CBM MVD and report about the status of our prototypingSpeaker: Mr Michael Deveaux (Goethe University Frankfurt)
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The Tracker Systems for the Muon Ionization Cooling ExperimentThe Muon Ionization Cooling Experiment (MICE) will be the first experiment to demonstrate muon ionization cooling in the momentum range of 140 MeV/c < p$_{\mu}$ < 240 MeV/c. The experiment is a single-particle experiment where the input and output beam emittances are made from an ensemble of selected single-muon candidates. The two fiber trackers in a solenoidal field of 4T (one before and one after the cooling channel) measure the muon 4-momenta and provide the basic information for determining the emittances. This paper gives a brief overview of MICE and then describes the details of the fiber tracker assemblies, their unique construction technique (which for the first time used 350 micron diameter scintillating fiber), the readout electronics and performance with respect to light yield, hit resolution and tracking efficiency as measured in a recent cosmic-ray test of the two final tracker systems.Speaker: Mr Christopher Heidt (University of California Riverside)
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Track and Vertex Reconstruction in the ATLAS ExperimentThe track and vertex reconstruction algorithms of the ATLAS Inner Detector have demonstrated excellent performance in the early data from the LHC. However, the rapidly increasing number of interactions per bunch crossing introduces new challenges both in computational aspects and physics performance. The combination of both silicon and gas based detectors provides high precision impact parameter and momentum measurement of charged particles, with high efficiency and small fake rate. Vertex reconstruction is used to identify with high efficiency the hard scattering process and to measure the amount of pile-up interactions, both aspects are crucial for many physics analyses. The performance of track and vertex reconstruction efficiency and resolution achieved in the 2011 data-taking period and perspectives for the 2012 data-taking, were improved algorithms will be used to are presented.Speaker: Dr Federico Meloni (University of Milano and INFN)
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Ultra-thin fully depleted DEPFET active pixel sensors for future e+/e- colliderPrototype DEPFET active pixel sensors designed for the vertex detector at the Belle-II experiment at KEK, Japan, and for experiments at a future linear collider have been produced on thin silicon-on-insulator (SOI) material. The DEPFET (DEpleted P-channel FET) is field effect transistor with an additional implantation beneath the transistor’s channel integrated on a fully depleted substrate. The inherent property of combined signal detection and signal amplification of the DEPFET allows the production of very thin sensors with an excellent signal-to-noise ratio for minimum ionizing particles. Combining a highly specialized MOS process which includes two poly-silicon and three metal layers on a fully depleted bulk with MEMS technology makes it possible to build thin wafer-scale (150 mm wafers) DEPFET active pixel sensors on a self-supporting all-silicon module. The paper will present the properties of the active pixel sensors designed for Belle-II and future liner collider applications and will give and overview of the manufacturing technology for thin fully depleted DEPFET. DEPFET prototypes produced on 50 micron thin silicon are operated using the control and read-out ASICs designed for the Belle-II experiment in various test conditions and show the expected performance e.g. in signal-to-noise ratio or pixel to pixel charge sharing.Speaker: Mr Christian Koffmane (Max-Planck-Institut für Physik)
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X-ray spectroscopic performance of a matrix of silicon drift diodesUsing $^{55}$Fe and $^{241}$Am sources we characterized the spectroscopic performance of a matrix of Silicon Drift Diodes (SDD). The matrix consists of a completely depleted volume of silicon wafer subdivided into 5 identical hexagonal cells. The back side is 5 implanted arrays of increasingly negatively biased concentric p+ rings. The front side, common to all 5 cells, is a shallow and uniformly implanted p$^+$ entrance window. Ionizing radiation impinging the detector bulk generates electrons that drift towards small readout n$^+$ pads placed on the back side in the center of each cell. The total sensitive area of the matrix is 135 mm$^2$, the wafer thickness is 450 µm. We report on the layout of the experimental set-up, as well as the spectroscopic performance measured at different temperatures and bias conditions.Speaker: Alexandre Rachevski (INFN - Trieste)
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GEM based detector for a future upgrades of the CMS forward muon systemIn perspective of an upgrade of the CMS Experiment, the GEM for CMS collaboration is performing feasibility studies on employing Triple-GEM detectors for the high-eta region (1.6-2.4) of the CMS Endcap, which is currently not instrumented. A detailed review of the development and characterization of the CMS full-size prototypes baseline detector will be presented. GEMs have excellent spatial and time resolution, high rate capability, and radiation hardness, they are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in this region. The GEMs for CMS collaboration has studied the performance of small and full-size prototype detectors during several test beam campaigns in order to prove compliance to the CMS requirements. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown for the small and large prototypes.Speaker: Stefano Colafranceschi (CERN)
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RD51 Collaboration - Micro Pattern Gas Detector Technologies and ApplicationsDriven by the availability of modern photolithographic techniques, the RD51 collaboration is developing a variety of new Micro Pattern Gas Detectors (MPGD). Developments cover Gas Electron Multipliers (GEM) and Micromegas, thick-GEM, resistive GEM (RETGEM) and novel micro-pattern devices like GridPix. The aims of the collaboration are to facilitate the development of these advanced gas-avalanche detector technologies and associated electronic-readout systems, for applications in basic and applied research. Areas of activity include MPGD technology and new structures, device characterization, software and simulations, electronics, MPGD production, common test facilities, and applications of MPGD. By this coverage of all aspects of MPGD, RD51 aims to bring together leading experts in the field for the development of new technology and colleagues using this technology for a wide array of applications. This paper will illustrate the activities of the RD51 Collaboration, give information on regular workshops, and show examples of MPGD applications across a broad spectrum from particle and nuclear physics, astro-particle physics, medical imaging, and homeland security. Special emphasis will be given to the possible MPGD technologies applications in the LHC experiments upgrades.Speaker: Leszek Ropelewski (CERN)
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The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searchesNeutrinoless double beta decay is a hypothetical, very rare nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a proposed 100-kg high-pressure xenon gas TPC that will search for neutrinoless double beta decay in Xe-136. Such a detector, thanks to its excellent energy resolution and its powerful background rejection provided by the distinct double beta decay topological signature, may become one of the leading experiments of the field. The project is proceeding through a fast R&D phase. The first prototypes, containing about 1 kg of pressurized xenon, are providing results already, as the demonstrations of tracking using PMTs and the measurement of the photoelectric peak of Cs-137 with 1% FWHM. This energy resolution extrapolates to 0.5% at the energies of Xe-136 decay. The final detector, NEXT-100, is planned to run at the beginning of 2014 at the Laboratorio Subterráneo de Canfranc (LSC), Spain.Speaker: Mr David Lorca Galindo (IFIC (Instituto de Física Corpuscular))
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GridPix - Production and Applications of Integrated Pixel ReadoutsMany experiments in particle physics employ Micropattern Gas Detectors (MPGDs) in combination with pads or stripes with a typical size of several square mm. With a pixelized readout structure the performance can be improved, as the size of the gas amplification stage is matched by the granularity of the readout. GridPix detectors are pixel chips with an integrated Micromegas structure, which has been added to the chip by techniques of industrial post processing. The holes of the grid are perfectly aligned to the pixels, i.e. there is only one hole above each pixel. Due to the alignment, amplification takes place directly above a single pixel and is mostly collected by this pixel. This way even single electrons of the primary ionization can be separated. Among the possible applications for GridPix detectors are particle tracking and X-ray detection. To study the tracking performance they have been tested in a time projection chamber (TPC) of 26 cm drift length. The results show that a spatial resolution near the diffusion limit of the drift gas can be achieved. Another TPC has been used to study the performance of X-ray detection. First studies show an energy resolution of about 5% for $^55$Fe sources. For the application in large experiments a large scale production process has to been developed, in which GridPix detectors are manufactured on a whole wafer instead per chip. This production process is presented additionally to the performance studies.Speaker: Mr Thorsten Krautscheid (Department of Physics, University of Bonn)
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HARPO - A Gaseous TPC for High Angular Resolution Gamma-Ray Astronomy and Polarimetry from the MeV to the TeVWe are developing a new concept of gamma-ray telescope above pair-creation threshold, with an angular resolution improved by one order of magnitude wrt Fermi / EGRET, polarisation sensitivity, and an effective area of several squared meters/ton. Improving the angular resolution is the key factor to lowering the sensitivity limit for point-like faint sources and fill the "sensitivity gap" between the low energy Compton telescopes and the present high energy pair-based telescopes. In particular the mapping of $E > 70$ MeV emission from the $\pi_0$ induced by hadronic interactions would help tracking the emission sources of the highest energy cosmic rays (protons) in the universe. Polarimetry of cosmic gamma ray sources has never been achieved in the energy range. It would provide new insight in understanding the emission mechanisms at work inside sources such as pulsars, AGN and GRB. Conservation of the linear polarisation of X-ray photons from GRB, along their path to us, is the most sensitive test of Lorentz invariance violation to date. Extending the energy range to gamma rays would further improve the sensitivity limit of these searches. The active target is a high-pressure TPC, with micromegas amplification and crossed-strips collection. A demonstrator has been built and is being tested with cosmic rays in the laboratory. We are planning to characterize its performance with a beam of polarized gamma rays.Speaker: Dr Denis Bernard (LLR Ecole Polytechnique)
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A TPC for the Linear ColliderA large TPC has been selected as one of two options for the main tracking at the Linear Collider. The LCTPC Collaboration has been conducting R&D in various directions for over 10 years. As a starting point, a Large Prototype consisting of a 72 cm diameter, 60 cm long field cage and an endplate with 7 windows capable of hosting 7 identical detection modules has been built and is operational since the end of 2008 in a superconducting magnet at DESY, for cosmic-ray and beam tests. Five amplification techniques are being studied in this setup and in smaller test devices: double-GEMs with 100 micron thick laser-etched GEM foils, Micromegas with a charge-dispersion anode, GEM read out by a TimePix pixellated chip, Micromegas grid integrated over a TimePix chip, and tripple-GEM with ceramic spacers. The main results from these various attempts will be presented. In parallel, studies are on-going on the effect of the space charge created by primary ionization and by backflow from the amplification region. Assessments of the track distortions due to the drift of electrons in the resulting electric field and in the solenoid magnetic field will be given and the need for a gating device will be discussed. Future plans, including power pulsing, electronic optimization and integration, cooling, and optimization of the mechanical structure, will be presented.Speaker: Paul Colas (CEA/Irfu Saclay)
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Gas Detectors - Poster Session
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Construction and Test of a Full Prototype Drift-Tube Chamber for the Upgrade of the ATLAS Muon Spectrometer at High LHC LuminositiesFor the planned high-luminosity upgrades of the Large Hadron Collider (LHC) background rates of neutrons and gamma rays of up to 14 kHz/cm$^2$ are expected which exceed the rate capability of the current ATLAS precision muon tracking detectors, the Monitored Drift Tube (MDT) chambers, with a drift tube diameter of 30 mm. So called sMDT chambers with a drift tube diameter of 15 mm have been developed for upgrades of the ATLAS muon spectrometer. A full sMDT prototype chamber has been constructed and tested in a muon beam at CERN and with cosmic muons at high gamma irradiation rates of up to 23 kHz/cm$^2$. The chamber design and construction procedures will be discussed. The test results demonstrate the required track reconstruction efficiency and spatial resolution of the sMDT chambers at background rates well beyond the maximum expected value. The sense wire locations in the prototype chamber have been measured with few micron precision with cosmic rays using precise reference chambers and confirm a wire positioning accuracy of better than the 20 microns required.Speaker: Dr Hubert Kroha (Max-Planck-Institut fuer Physik, Munich)
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Development of 2d- and 3d- coordinate single plane readout for GEM detectors.The development of different detectors based on GEM technology both for PID and tracking including detailed detector response simulation will be discussed. Description of the GEM foil (Tech-Etch production) selection and test procedure will be presented. A new approach for low mass, single plane 2d- and 3d- readout for GEM detectors and test results will be described.Speaker: Dr Nikolai Smirnov (Yale University)
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Development of large-area resistive-strip micromegas chambers for the ATLAS muon system upgradeResistive-strip micromegas are bulk micromegas chambers incorporating an efficient spark protection scheme. They are particularly suited for high-rate applications in a harsh radiation environment. They were developed for the upgrade of the ATLAS muon system upgrade (Small Wheel) for the high luminosity LHC. The characteristics of the resistive micromegas chambers, highlights of the development, and the status and the prospects of the work on large-area chambers with two-coordinate readout are presented. In a more general approach, the technology’s strong points and its limitations are discussed.Speaker: Dr Marcin Byszewski (CERN)
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Gas multiplication process in high pressure proportional countersSystematic measurements of gas amplification factors over the range 1 to 5 10$^5$, were performed for Ar + 20%CO$_2$ and Ar + 6.4% CO$_2$+ 2.5% N$_2$ mixtures as a function of the applied voltage between cathode and anode for the following working gas pressure: 0.05, 0.1, 0.3, 0.5 and 0.65 MPa. Full current characteristics, starting from recombination mode up to limited proportionality, have been measured. Single anode (radius of anode ra = 10, 15 and 25\, $\mu$m) cylindrical counters ( radius of cathode rk = 4, 5 and 6.5 mm) were used for the measurements. First Townsend coefficients were also determined. Obtained results will be presented.Speaker: Dr Tadeusz Kowalski (AGH, University of Science and Technology, Cracow)
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GEM Detector Development for CBM experiment at FAIRA large area, high granularity and high rate gas detector has been proposed for the detection of muons in the Compressed Baryonic Experiment (CBM) in the upcoming FAIR facility in Germany. The main task of the Muon Chambers (MUCH) is to detect dimuon signals arising from the decay of the low mass vector mesons and those from the decay of charmonia produced in the heavy ion collisions at FAIR. The main challenges for MUCH includes a high event rate of $~10$ MHz and high radiation environment, besides others. The MUCH system consists of alternating layers of absorbers and tracking chambers. We at VECC, Kolkata, are involved in the design and development of GEM based detector for the first few planes of MUCH where the particle density is about 1 MHz/cm$^2$. Several triple GEM prototypes with 2D pad readout were built at VECC and tested both with radioactive sources and proton and pion beams. The chambers having realistic pad granularities were tested using a self triggered electronics, collecting data in a free streaming mode, as the case would be in the actual experiment. Events are then reconstructed offline by associating the hits with the trigger on the basis of their time-stamps. A charged particle detection efficiency greater than 90$\%$ was achieved from these tests. Design and assembly of large size GEM chambers based on sector layout is underway. Details on the chamber design, fabrication and optimization of the operating conditions would be presented and discussed.Speaker: Dr Anand Dubey (VECC, Kolkata)
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High rate GRPC for muon detectors upgrade at LHCThe limitation of the detection rate of standard bakelite RPC used as muon detectors in the LHC experiments has prevented the use of such detectors in the high eta regions in both CMS and ATLS detectors. The same statement applies for the already instrumented regions in the LHC high luminosity scenario. One of the alternative to these detectors, is the use of RPC detectors with low resistivity glass plates (10$^{10}$ Ωcm). Several beam tests at CERN and DESY have shown that such detectors can operate at few thousands KHz/cm$^2$ with high efficiency( > 90%). Aging problems were also studied at the GIF facility at CERN and found to be absent after one year of irradiation. The advantages to use such GRPC as high rate muon detectors is the sub-nanosecond time precision it provides. This is of the utmost importance to reduce the background contribution by improving on the trigger efficiency. The cost of such detector and the fact that it uses the same gas mixture as the standard RPC are also important aspects that favor the use of these detectorsSpeaker: Mr Yacine Haddad (LLR - Ecole Polytechnique)
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High-Resolution Micromegas Telescope for Pion and Muon TrackingA recently developed beam telescope, consisting of four Micromegas detectors with standard copper anodes of 360 strips and an active area of $9\,\mathrm{cm}\times10\,\mathrm{cm}$, has been tested in 160\,GeV pion and 140\,GeV muon beams at the SPS at CERN. The 1500 anode-channels of 250 $\mu$m strip pitch are read out using a Gassiplex-frontend based electronics, originally developed for the HADES RICH detector, that has been adapted to the negative Micromegas signals. The telescope was operated stably over several weeks with an efficiency close to 100\%. Collecting around 20 million pion and muon tracks, two different Ar:CO$_2$ gas mixtures, 93:7 and 85:15, have been tested at 1016\,mbar. The dependence of the single detector spatial resolution on a variety of parameters has been investigated. For both gas mixtures a best value of 35\,$\mu$m is reached by maximizing the number of electrons entering the amplification region. The resolution depends only weakly on the gas-gain. The combination of four detectors allows thus for a track accuracy of 20\,$\mu$m. The discharge rate in the pion beam with a flux-density of 4 kHz/cm$^2$ was around $10^{-5}$ per pion and thus negligible, the discharge rate was even smaller for muons. The development of a $48\,\mathrm{cm}\times50\,\mathrm{cm}$ Micromegas detector with floating strip technology for improved discharge behavior in densely-ionizing neutron and proton beams is ongoing.Speaker: Mr Jonathan Bortfeldt (LMU Munich)
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Micromegas for CLAS12 experiment at Jefferson LaboratoryThe electron accelerator of the Thomas Jefferson Laboratory (Virginia, USA) will soon be upgraded to deliver 12 GeV high intensity beams. This increase of performance will give the opportunity to study the nucleon structure with an unprecedented accuracy. To meet this end, new equipments will be installed in the experimental areas, particularly in the Hall B/CLAS spectrometer. One of the most challenging aspects is the installation of a Central Tracker surrounding the target, dedicated to the detection of particles emitted at large angles. Micromegas detectors have been chosen to be a major element of this new equipment, due to their high rate capability as well as their robustness and light material. Using the recent bulk technology, part of these gaseous detectors are planned to be assembled in thin cylinders to maximize the acceptance. On the other hand, the presence of a strong magnetic field either perpendicular or parallel to the readout strips has important consequences which need to be carefully investigated. Finally, hybrid technologies like Micromegas-GEM or resistive layers have also been studied to further improve the rate capability. The R&D carried out and the status of this project, which could benefit to future high luminosity experiments, will be presented.Speaker: Mr Gabriel Charles (CEA Saclay)
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NEXT prototyes based on Micromegas readoutsThe NEXT experiment will look for neutrinoless double beta decay in Xenon-136 in a high Pressure Time Projection Chamber (TPC). The detector is based on electroluminiscence light measured with photomultipliers and silicon photomultipliers (SiPMs). In parrallel with the baseline NEXT design an R\&D line based on Micromegas detectors with pixelized anode was developed as an option to detect both, energy and topology of the signals. Micromegas are a good option in rare event searches (such as dark matter, axions or double beta decay) because of their high radiopurity, robustness and performance regarding energy resolution and pattern recognition. In this R\&D prototype readouts based on Micromegas detectors were constructed to study their properties at different pressures and gas mixtures and also to test microbulk Micromegas in realistic conditions (electron tracks fully contained). Here we will present the results on the commissioning and performance of these prototypes.Speaker: Mrs Laura Segui (University of Zaragoza, Spain)
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Operation of the AMS-02 TRD in SpaceThe AMS-02 detector was installed on May 2011 on board of the International Space Station, and has since collected billions of cosmic ray events. AMS will measure with unprecedent precision cosmic ray spectra up to the TeV energy scale, achieving a sensitivity to the existence of anti-helium nuclei of one part in a billion, as well as providing important information on the origin of dark matter. A Tranisiton Radiation Detector, filled with a Xe/CO$_2$ mixture, is used to reach the sensitivity to positron identification needed for the detection of a neutralino dark matter candidate. The control of a gaseous detector in Space is a challenging task: the operational procedures, and the performances achieved, will be described.Speaker: Dr Francesca Romana Spada (INFN - Roma 1)
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Operations and Performance of the CMS RPC muon system at LHCThe Resistive Plate Chambers are used in CMS as dedicated muon trigger in both barrel and endcap region. They also contribute to the identification of the muons together with Drift tube in the barrel and Cathod Strip Chambers in the endcaps. We will report the operations and performance of the system after two years of LHC activities with increasing instantaneous luminosity. Special attention will be given to the stability of the system and to the working point calibration procedures.Speaker: Dr Anna Cimmino (UGent)
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Production and test of the first two layers of the KLOE-2 Inner TrackerThe upgrade of the KLOE detector foresees the insertion of a new Inner Tracker device around the interaction region of the DAFNE $\Phi$-factory, composed by four tracking layers with diameters from 260 mm to 410 mm and an active lenght of 700 mm. They are realized as cylindrical triple-GEM detectors, a solution that allows to keep the total material budget under 2\% of $X_0$ minimizing dead spaces. The peculiar readout pattern with XV strips provides a spatial resolution of about 200 $\mu$m on both views. The readout system has been completely developed within the KLOE-2 collaboration. It is composed by a digital readout front-end card based on the GASTONE ASIC and a General Interface Board with a configurable FPGA architecture and Gigabit Ethernet. We have built the two innermost layers that have been extensively tested with 5.9 keV X-rays and cosmic rays. We will report the construction procedure and the results of the validation tests.Speaker: Danilo Domenici (LNF)
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Production status of the JLAB Hall-A GEM and Si µstrip TrackerWe developed and tested a new charged particle tracking system, able to operate in high luminosity experiments, which will be installed at Jefferson Laboratory HallA (VA, USA) for optimally exploit the new 12 GeV energy electron beam available at the end of 2013. The tracker is made of 6 GEM (Gas Electron Multiplier) large chambers and two 10x20 cm$^2$ planes of SIilicon microstrip Detectors (SID). Each GEM chamber is composed by three 40x50 cm$^2$ GEM modules, with 2 dimensional strip readout, with expected spatial resolution of about 70\, $\mu$m. The same dedicated acquisition system will be used for both detectors (GEM & SID) for a grand total of more than 50000 channels. The readout electronics is divided in two parts: the front-end cards (based on existing APV25 chip), hosted on the detectors periphery and the digitizer, a multi purpose VME-64x/VXS board located far from the high radiation environment. The very same electronics has been adopted by the Olympus experiment (DESY, Hamburg, D) to read out the 6 GEM chambers of its luminosity monitor. The developed detectors and electronics are now ready for the production, which will last for the next 2 years. We report on the measurements done in test beams and in a real experiment and on the procurement status.Speaker: Dr Paolo Musico (INFN Genova, Genova, Italy)
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RPC hit contribution to CMS muon reconstruction at LHCThe Resistive Plate Chambers (RPC) are used as dedicated trigger detector in both Barrel and endcap regions of the CMS experiment together with Drift Tubes and Cathode strip Chambers. The redundancy of the Muon system of CMS is used also to improve the muon identification including the RPC hits in the muon identification and reconstruction algorithms. The poster will describe the performance of the contribution of RPC hits in the muon identification and how they complement the main muon tracking devicesSpeaker: Dr Hyunkwan Seo (Sungkyunkwan University)
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Secondary avalanches in gas mixturesAvalanche development in gas-based detectors relies not only on direct ionisation but also on excitation of noble gas atoms. Excited atoms can, in some gas mixtures, ionise the quencher molecules they collide with. We have reported on this process earlier. Alternatively, excited atoms can decay by photon emission. If these photons are insufficiently absorbed by the quencher, yet capable of ionising, then they may escape from the avalanche region and start secondary avalanches. This process, called photon feedback, leads to an over-exponential increase of the gas gain which limits the working range. In this paper, we derive photon feedback parameters from published gain measurements for several gas mixtures and fit these parameters in a model which describes their dependence on the quencher concentration and the pressure.Speaker: Ozkan Sahin (Department of Physics Uludag University, Bursa, Turkey)
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Setup Optimization Toward Accurate Ageing Studies of Construction Materials of Gaseous DetectorsAn infrastructure has been set up at the GSI detector laboratory to study the influence of construction materials on the ageing properties of gas filled detectors, such as multi wire proportional chambers (MWPC), gas electron multipliers (GEM) etc. Two identical MWPCs have been used for these tests, one of them has been contaminated with the outgasing material under investigation, and the other has been used as reference. The gain ratio of these two chambers has been used to measure the onset of ageing if any. In the ageing studies, is important to distinguish the permanent degradation of the gain ratio due to ageing and the temporary variation due to the effect of ambient parameters. To distinguish the above mentioned difference, a high precision measurement is required to be performed in reasonable time period. In this aspect the temperature effect on the behavior of the gas mixing station which contains two Mass Flow Controllers (MFC) has been studied systematically. The periodic gain ratio variation has been observed with mixing station and with premixed gas. Ageing test on different construction materials have been performed. In this article, details of the experimental setup at the GSI detector laboratory, systematic optimization tests, and ageing test results on different construction materials will be presented.Speaker: Mr Alhussain Abuhoza (GSI)
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Study of the characteristics of GEM detectors for the future FAIR experiment CBMGEM will be used in CBM Muon Chamber (MUCH) located downstream of the Silicon Tracking System (STS) of the CBM experiment along with other sophisticated detectors. In GSI detector laboratory an R&D effort is launched to study the characteristics of GEM detectors for the CBM experiment. The primary goals of this R&D program are: (a) to verify the stability and integrity of the GEM detectors over a period of time, during which a charge density of the order of several Coulomb/cm$^2$ is accumulated in the detector; (b) to establish the functioning of a triple GEM as a precise tracking detector under the extreme condition of the CBM experiment; (c) to study usual parameters e.g., efficiency, rate capability, long term stability, spark probability by varying conditions like temperature, gas composition or radiation dose. One triple double mask GEM detector obtained from CERN with 3 mm drift gap, 2 mm transfer gap and 2 mm induction gap has been studied systematically. The voltage to the drift plane and individual GEM plates has been applied through a voltage divider chain. The signals obtained from all readout pads summed by an add-up board and a single input is fed to a charge sensitive preamplifier. A LabView based data acquisition system is used. The variation of the effective gain, resolution of this detector with variation of the applied high voltage has been measured with $^{55}$Fe X-ray source for different gas mixtures and with different gas flow rates etc.Speaker: Dr Saikat Biswas (GSI Helmholtzzentrum für Schwerionenforschung GmbH)
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The Thin Wall Drift Tube Chamber Operating in Vacuum (Prototype)We describe the prototype implemented design and assembly technology of the drift chamber for operation in the vacuum. The main features of the proposed drift chamber are the following: 1. As single detector unit the thin-wall mylar drift tube with diameter of 10 mm, length of 2160 mm and Cu+Au plated is used. The tubes are produced by ultrasonic welding, using welding device and method developed at JINR. 2. The complete assembly of drift tubes with end plugs, anode wire and its supports takes place outside the chamber. 3. For precision installation of anode wires and tubes «self-centering» spacers and bushes are used. 4. Each of the assembled tubes is installed in the chamber, vacuum sealed with O-rings and stretched separately. Application of O-rings simplifies and reduces the cost of the chamber assembly and the failed tubes replacement. 5. Assembly of tubes and manufacturing of a load carrying structure of the chamber are made simultaneously and independently to reduce essentially total assembly time. 6. Full assembly of drift tubes outside the chamber with their subsequent installation in a prototype for vacuum and electric tests is carried out. Operating characteristics of drift tubes are measured. 7. The assembling technology of tubes outside the chamber is suitable for any shape chambers, but for the vacuum condition the round one is preferable. Chamber of such a design has been considered. Its advantages of operation in vacuum are shown.Speaker: Dr Levan Glonti (Joint Institute for Nuclear Research, Dubna)
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Ultra-Light Gas Mixtures for Drift ChambersWe present results on the measurements of gas gain for gas mixtures at absolute pressure below the atmospheric pressure, down to 100 mbar, and their relative stability. Besides the obvious advantage of further limiting the contribution to the momentum measurement due to multiple scattering, the operation at low pressure allows for a fine tuning of the working parameters of a drift chamber like drift velocity, diffusion and specific ionization. Furthermore, such a possibility is of particular interest for experiments like the direct muon to electron conversion experiment Mu2e at Fermilab, where the tracking detector needs to operate in vacuum. Plans for extending the measurements to transport parameters, like drift velocity and diffusion, will also be presented.Speaker: Michele Cascella (Università del Salento e INFN)
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Ultra-low mass Drift ChambersWe present a novel low mass drift chambers assembling technique, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100-200 KeV/c) for particles momenta in a range (50-100 MeV/c) totally dominated by the multiple scattering contribution (e.g., the positrons in MEG at PSI and the electrons in Mu2e at Fermilab). Detailed studies for defining proposed geometries and the choice of materials designed for the mechanical structure, leading to end plates thicknesses of the order of 0.2 g/cm$^2$, corresponding to 0.5% of a radiation length, inclusive of the front-end electronics, will be illustrated. We describe the new wiring strategy and the feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce. Its first results, under a cosmic rays test stand, are expected in the forthcoming weeks.Speaker: Francesco Grancagnolo (LE)
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Experimental Systems without Accelerators
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Operating the GridPix detector in dark matter search experimentsThe DARWIN design study aims to use liquid argon and liquid xenon targets to look for nuclear recoils due to Weakly Interacting Massive Particles. To measure the recoil energy in dual-phase noble gas time projection chambers the combination of scintillation and ionisation detection is used to discriminate nuclear from electron recoils. Current experiments use an array of photomultiplier tubes to detect the primary scintillation and the ionisation electrons via secondary scintillation in the gas phase. Within the research framework for DARWIN, one candidate for an alternative charge readout is GridPix, a micro-pattern gaseous detector composed of a Micromegas-like amplification grid over the Timepix 65k pixel readout chip. It can achieve a single-electron detection efficiency of up to 98 % and has thus great potential to identify the ionisation electrons in dark matter search experiments. The main challenges for this application are low outgassing, thermal robustness, and operation in pure (thus quencher-free) noble gas. To investigate its applicability we operated a GridPix detector in a dual-phase argon cryostat. We proved GridPix's perfomance in pure argon. The gas amplification was confirmed in pure argon in the broad temperature range from 300 K down to 87 K. Moreover, we will present results of studies in pure xenon gas at room temperature.Speaker: Rolf Schön (Nikhef)
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The XENON Program: Results from XENON100 and the Evolution Towards the Ton ScaleThe XENON experimental program is aimed at the detection of Dark Matter in the form of Weakly Interacting Massive Particles (WIMPs), using liquid xenon as target and the 'double phase' technique to discriminate nuclear recoils (the signature of WIMPs) from the ordinary radioactive background. The XENON colaboration has already deployed two successful detectors at the Gran Sasso Laboratory. I will review the recent results from XENON100, which employs 160kg of target, and then will illustrate the new XENON1T detector (with a total of 2.5t of xenon), whose installation will start in 2012, always at Gran Sasso.Speaker: Francesco Arneodo (LNGS)
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First Measurement with Argontube, a 5m long drift Liquid Argon TPCFor future neutrino oscillation experiments new large mass scale detectors are needed. One possible type of such detectors could be a liquid Argon Time Projection Chamber (LArTPC). Some technical challenges need to be addressed, like the purity of the LAr, the high voltage supply and calibration. To face these challenges, an R\&D program named Argontube is in progress at the LHEP of Albert Einstein Center of Fundamental Physics at the University of Bern. The goal is to reach a charge drift length of $5$ m in liquid Argon and prove the feasibility of large volume TPCs. The Argontube detector is now built and running. In this talk, different aspects of the technology will be reviewed and new results of the first runs using the 5m long TPC will be presented.Speaker: Mr Marcel Zeller (University of Bern)
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Liquid scintillator time projection chamber conceptResults are presented from a small-scale experiment to investigate the use of room temperature organic liquid scintillators as the active medium for a time projection chamber (TPC). The optical properties of liquid scintillators have long been known, but their ability to transport charge has remained, until now, largely untested. The idea of using room temperature liquids as an active medium for an ionisation chamber was first presented in [1]. Since then the range of liquid scintillators available has been greatly developed. A selection of organic liquid scintillator cocktails have been tested, and it has been shown that charge can be transported over at least 20mm using an electric field of 0.5\,kVcm$^{-1}$ in the liquid scintillator Di-isopropyl napthalene (DIN). [1] R. A. Holroyd, D. F. Anderson, Nucl. Instr. Meth. A 236 (1985) 294-299Speaker: Ms Nicola McConkey (University of Warwick)
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The EXO-200 double beta decay experimentThe Enriched Xenon Observatory (EXO) experimental program is searching for the neutrino-less double beta decay of xenon-136. A first stage experiment called EXO-200 is running at the WIPP salt mine in New Mexico, and has made the first measurement of the standard electroweak 2-neutrino double beta decay of Xe-136. EXO-200 uses 200 kg of xenon enriched to 80% in the 136 isotope, a large fraction of which is liquefied and constitutes the source and active medium to detect ionizing interactions in its bulk. The detector is instrumented as a double time projection chamber (TPC) in which both the ionization and the scintillation signals are detected to maximize energy resolution. The entire detector is designed to achieve the lowest possible radioactive background in its xenon core, and implements numerous innovative detector technologies. Noteworthy are the use of ~500 silicon avalanche photodiodes to detect the 175 nm xenon scintillation, the thin copper shell used to contain the xenon and the electrical connections, spring-loaded with no use of solder joints or connectors. The talk will highlight these pioneering features of the EXO-200 detector and report on the latest physics results from the experiment.Speaker: Prof. Andrea Pocar (University of Massachusetts, Amherst)
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coffee break
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New Development of Silicon Drift Detectors for Gamma-ray AstronomyIn this work we report on a new development of Silicon Drift Detectors (SDDs) for gamma-ray spectroscopy for astronomy applications, an activity supported by ESA. The SDDs are designed as monolithic arrays of 3x3 units, each one of an active area of 64mm$^2$ (total array area of 5.76cm$^2$). These arrays will be assembled on a common substrate to be used as photodetector to read out large (2”x2” and 3”x3”) LaBr3 scintillators. The SDDs have been produced at FBK semiconductor laboratories. For the electronics readout of these devices, which do not include a front-end transistor on the detector chip, we have adopted a CMOS charge preamplifier (CUBE), recently developed at Politecnico di Milano. This preamplifier has allowed to achieve state-of-the-art noise performances, even if compared with SDD with on-chip JFET, and it is a suitable solution for this application as it allows to use a relatively standard SDD technology process with very good noise performances. The SDDs have been produced for this application with custom anti-reflective-coatings. A quantum efficiency of about 80% has been measured on these devices at the wavelengths of emission of LaBr3 (360-380nm). In this work we will report on the design issues of these devices and on the first experimental results obtained in gamma-ray spectroscopy. By coupling a single SDD with a small LaBr3 scintillator (6mm diameter), we have measured an energy resolution of 5.6% FWHM and 2.7% FWHM respectively at 122keV and 662keV.Speaker: Carlo Fiorini (Politecnico di Milano and INFN, Milano, Italy)
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The LUX Dark Matter DetectorThe Large Underground Xenon (LUX) is a dark matter direct detection experiment being deployed at the Homestake Mine in South Dakota, USA. The LUX detector is a dual-phase Xe TPC, with a total liquid Xe mass of 350 kg. It measures both scintillation and ionization produced by radiation interacting in the liquid Xe to differentiate between the nuclear recoils expected from WIMPs and the electron-recoil background signals. The LUX experiment aims at a sensitivity of 7E-46 cm$^2$ for the WIMP-nucleon cross-section for a 100 GeV/cm$^2$ WIMP, an order of magnitude better than the existing results. While leveraging the well stablish dual-phase Xe technology (proven by ZEPLIN and XENON experiments), LUX adds technological improvements in key areas, such as shielding and cryogenics, required for the next generation of 1-10 ton dark matter detectors. The detector has recently finished a period of calibration and testing of all subsystems at a surface facility at Homestake and is currently being prepared for underground commissioning by mid-2012. In this talk, we present the experiment and its status, with a focus on the design elements that make the detector a major competitor in the field of dark matter detection.Speaker: Dr Francisco Neves (LIP - Coimbra)
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Commissioning and performance of the external injection bench seismic attenuation system for the Advanced Virgo gravitational wave detectorRecently, the upgrade of the Virgo gravitational wave detector was kicked off with the installation of the new seismic attenuation system for the external injection bench. In the next two years the sensitivity of Virgo will be improved by an order of magnitude and it is believed that with its improved capability, Advanced Virgo will herald the era of gravitational wave astronomy. The enhanced sensitivity of Advanced Virgo can only be achieved if the seismic isolation of several optical benches, hosting ancillary optics and angular and longitudinal sensing photo-diodes, is improved. In particular, the external injection bench was found to be major source of beam jitter in Virgo+. New bench support structures, capable of attenuating seismic motion from 60 to 160 dB (> 10 Hz) in all six degrees of freedom are being constructed at Nikhef. To reach the required performance these seismic attenuation systems make use of passive filters: short inverted pendulums and geometric anti-springs. Low frequency resonances are actively damped with a feedback system using accelerometers, LVDTs and voice coil actuators. Apart from systems that will be operated in air, systems that can operate in vacuum are being constructed. The installation and commissioning of the first of these systems was completed in March 2012. We will give an overview of the design, installation and commissioning of this system and show the performance we have achieved.Speaker: Mr Mathieu Blom (Nikhef Amsterdam)
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The AMS-02 Detector: Design and Operation on Board the International Space StationThe Alpha Magnetic Spectrometer (AMS-02) is a high-energy physics experiment designed to operate in space on board the International Space Station (ISS), where it has been installed on May 16th 2011. Thanks to the very large acceptance ($\sim$0.5 m$^2$ sr) and an exposure time of several years, matching the ISS lifetime, AMS-02 will measure a wealth of data to study with unprecedented accuracy the composition and the energy spectrum of charged CRs and gammas up to the TeV energy scale, allowing for the search of primordial antimatter and dark matter annihilation products. Nine layer of silicon microstrip detectors constitute the core of the spectrometer, allowing the simultaneous measurement of the charge magnitude and sign of impinging particles and reconstructing their rigidity up to the TV. A 3D imaging calorimeter, with a depth of 16 radiation lengths and a TRD detector allow an accurate measurement of the electron and positron components of CRs, allowing an effective rejection of the proton background. Velocity measurement and redundant charge measurement are performed by the scintillator planes of the Time of Flight system and a Ring Imaging Cherenkov detector. During the first nine months of data taking, $\sim$1.5 10$^{10}$ triggers have been recorder: we will report on the flight operations and performance of AMS-02 and its perspective for physics measurements. The design, integration and ground calibration of the detector will also be reviewed.Speaker: Dr Giovanni Ambrosi (INFN Perugia)
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Radio Detection of Extended Air Showers at the Pierre Auger ObservatoryThe Pierre Auger Observatory explores the potential of radio detection techniques to measure extensive air showers (EAS) induced by ultra-high energy cosmic rays. To study in detail the mechanisms responsible for radio emission in the MHz range, the Auger Engineering Radio Array has been installed at the Observatory. Presently consisting of 24 radio-detection stations, this number will grow to 150 units covering an area of almost 20 km$^2$. Novel detection techniques based on the GHz emission from the EAS are currently being studied. AMBER (Air-shower Microwave Bremsstrahlung Experimental Radiometer) and MIDAS (Microwave Detection of Air Showers) are prototypes for a large imaging dish antenna. In EASIER (Extensive Air Shower Identification using Electron Radiometer), the microwave emission is detected by antenna horns located on each surface detector. MIDAS is a self-triggering system while AMBER and EASIER use the trigger from the Auger detectors to record the emission.The status of these radio detection R&D efforts at the Pierre Auger Observatory will be reported.Speaker: Dr Corinne Berat (Laboratoire de Physique Subatomique et de Cosmologie (LPSC))
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Experimental Systems without Accelerators - Poster Session
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17O(p,a)14N study at the LUNA acceleratorHydrogen burning of 17O sensitively influences nucleosynthesis in a number of stellar sites, including red giants, asymptotic giant branch (AGB) stars, massive stars, and classical novae. In particular, the ratio between reaction rates of 17O(p,alpha)14N (Q = 1.2 MeV) and 17O(p,g)18F (Q = 5.6 MeV) channels on 17O is one of the most important parameters for the galactic synthesis of 17O, the stellar production of radioactive 18F, and for predicted O isotopic ratios in premolar grains. Now the LUNA collaboration operating inside the underground laboratories of LNGS is preparing a new effort to study the (p,alpha) channel on 17O at astrophysical energies. To reach this goal a new chamber has been constructed which allows to place 8 silicons detectors covering almost half of the total solid angle in backward directions. The setup improves the efficiency which is a crucial parameter in measuring nuclear reaction at such low energies. Aluminum foils are placed on the silicon in order to stop the elastic backscattered protons which otherwise produce non negligible background on the silicons. The target chamber is made by two semispherical structures: one holds the silicon and the other one made in copper is connected to the beam line cold trap in order to avoid contaminants on the target surface and to keep cold the silicons reducing the noise also in the low energy region where we expect the alpha particles signal.Speaker: Dr Antonio Caciolli (INFN Padova)
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A software algorithm to lower the energy threshold of a bolometric light detectorsBolometric detectors are one of most promising techniques to search for neutrinoless double beta decay. They are calorimeters working at cryogenic temperatures, featuring low background and excellent energy resolution. It has been demonstrated that the main source of residual background is due to α particles generated by natural radioactive contaminants of the detector materials. This background can be identified by detecting the light emitted by particles in their interaction in the bolometer, via scintillation or Cherenkov processes. Indeed α and β/γ events emit different amounts of light for the same energy released in the bolometer. Due to the work temperature, the light detector typically is a second bolometer, generally a germanium thin disk. The correct evaluation of the light amount and a low energy threshold for the light detector are of primary importance to improve the event discrimination, particularly when the amount of light is small. In this work a software algorithm to lower the energy threshold of bolometric light detectors is presented. This algorithm is applied to light detectors faced to two bolometers: a scintillating ZnMoO4 and a TeO2, used to search the neutrinoless double beta decay of Mo-100 and Te-130, respectively. This show an energy threshold lowering by a factor of 3. In particular we were able to discriminate for the first time α and β/γ interactions in TeO2, opening the possibility to improve the sensitivity of upcoming experiments.Speaker: Mr Gabriele Piperno (Sapienza University of Rome)
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Acoustic Position Calibration of the KM3NeT Neutrino TelescopeKM3NeT is a European Consortium with the goal to build and operate a neutrino telescope with a volume of several cubic kilometres at the bottom of the Mediterranean Sea. It will be composed at least 300 vertical structures of several hundred metres length, named detection units (DU), anchored on the seabed and kept vertical with a buoy. The DU will host optical sensors able to detect the faint Cherenkov light emitted in the deep sea from the tracks of charged particles originating from collisions of the neutrinos with nuclei in the sea water or the rock below. A precise knowledge of the optical sensor relative positions of not worse than 20 cm is needed for an accurate reconstruction of the charged particle tracks. Since the marine currents cause movements of the DUs and thus a displacement of the optical sensors of up to several ten meters from their nominal positions, an Acoustic Positioning System (APS) is necessary to monitor their positions in deep sea. The telescope will employ an APS composed of acoustic transceivers at fixed positions on the sea floor and acoustic receivers (hydrophones) along each DU. The hydrophone positions are calculated by triangulation using the times travel of acoustic signal between emitter and receiver. The poster will present the acoustic positioning system designed for KM3NeT and in particular the innovative technologies used for transducers, electronics, and signal processing.Speaker: Ms Giuseppina Larosa (UPV-IGIC)
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ARGO-YBJ: physics results and detector stabilizationThe ARGO-YBJ experiment at 4300 m above sea level on the Tibet plateau is a full-coverage array of Resistive Plate Chambers (RPCs) operated in streamer mode, covering a surface of 74 ×78 m$^2$ surrounded by a guard ring. It has been running uninterruptedly with its complete layout since October 2007, providing results in gamma-ray astrophysics and cosmic-ray physics. The results of ARGO-YBJ in the study of TeV gamma rays from Supernova Remnants and from Active Galactic Nuclei and in the study of medium-scale cosmic-ray anisotropies will be described in detail. The monitoring information is provided by the Detector Control System (DCS). The environmental parameters and the high-voltage power supplies are constantly monitored. The recorded changes of temperature and barometric pressure affect the density of the gas mixture inside the detector and consequently its behaviour, in particular the time resolution and, to a lesser degree, the efficiency. In view of an extended data-taking period for the experiment a procedure in order to stabilize the detector response was devised. It is based on the information provided by the DCS to trigger a feedback control algorithm acting on the high-voltage power supplies. Here we present the main physics results obtained by the ARGO-YBJ Collaboration since the start of the data taking in 2007. We also discuss the test which proves the feasibility of the control procedure devised to stabilize the response of the detector.Speaker: Dr Paolo Camarri (INFN - Roma2)
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Axion search by Laser-based Experiment OSQAROSQAR experiment in CERN is laser-based experiment for search of axions. Two methods are used for this research. The first one, the photon regeneration effect is looked as a light shining through the wall, whereas in the second one, ultra-fine magnetic birefringence of the vacuum is aimed to be measured for the first time. The photon regeneration experiment is using two LHC dipole magnets of the length 14.3 m and magnetic field 9.5 T equipped with an optical barrier at the end of the first magnet. Argon laser is a source of 7 W beam. The CCD detector, cooled by liquid nitrogen, measures the laser beam profile by photon counting method. No excess of events above the background was detected at this arrangement. The second method at OSQAR experiment want to measure for the first time the ultra-fine Vacuum Magnetic Birefringence predicted by the QED. An optical scheme has been proposed, validated and subsequently improved in collaborating institutes. The integration of the newly developed ultra-fine ellipsometry to OSQAR LHC magnets set-up is in preparation.Speaker: Dr Miroslav Sulc (Technical University of Liberec)
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Characterization of BEGe Detectors in the HADES Underground LaboratoryA complete characterization of new Germanium detectors of BEGe type is being carried out in the HADES underground laboratory, located 225 m below ground in Mol (Belgium). The aim is to determine all the important operational parameters, like the detector active volume, the dead layer thickness and uniformity over the surface and to test the performance of the diodes in terms of energy resolution and quality of pulse shape discrimination. Authomatized acquisition systems, both analog (MCA) and digital (FADC), will be run in parallel. Two types of mechanical set-ups have been designed for the tests. One type consists of a simple measurement table, with a lead shield surrounding the detector, suitable for measurements with a test source placed in fixed positions (collimated or uncollimated). A second one is provided with a movable, motor controlled harm, which allows performing a full area scanning of the diode with a collimated source. This work aims at describing the test procedure and the measurement setups, as well as the preliminary results obtained and the potential applications which can be derived.Speaker: Dr Erica Andreotti (JRC-IRMM)
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CUORE: a Neutrinoless Double Beta Decay experimentThe Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay (0νDBD) in Te-130 and other rare processes. The observation of 0νDBD would indicate that neutrinos are Majorana particles and would provide information about the absolute neutrino mass scale. CUORE is a bolometric detector composed of 988 TeO2 crystals, with the total mass of about 750 kg of natural Tellurium that will be operated in the hall A of the Gran Sasso underground Laboratory to shield cosmic rays. The status of the CUORE experiment will be discussed including recent R&D efforts, anticipated sensitivity, and background evaluations. The installation of CUORE-0 detector, the first tower of CUORE, is ongoing. Preliminary results will be discussed considering all the possible aspects that are crucial to reach the goal of the CUORE experiment.Speaker: Ezio Previtali (MIB)
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Detecting Long Baseline Neutrinos in the NOvA ExperimentThe NOvA Collaboration is building a massive tracking liquid-scintillator calorimeter at a location in Northeastern Minnesota, which is 14 mrad off-axis of a high power muon neutrino beam (NuMI) originating 810 km away at the Fermi National Accelerator Laboratory (near Chicago), for the purpose of recording the appearance of electron neutrino events. The principle goals are in comparing neutrino events in a near and far detectors to establish electron neutrino appearance and a non-zero neutrino mixing angle $\theta_{13}$, thus observing CP violation in neutrinos and resolving the neutrino mass hierarchy. Other important oscillation parameters will be recorded to improve knowledge of this phenomena. This calorimeter will be sensitive to supernova neutrinos. Building such a detector is not without challenges. In this talk we discuss the physics goals, describe the detecting components, and provide a status report on its installation and operation. Reference: http://www.umn.edu/~demuth/nova/Speaker: Dr David DeMuth (University of Minnesota, Crookston)
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Developments of Microresonators Detectors for Neutrino Physics in MilanoLow temperature detectors have proven that they are suitable for energy spectrometry. Nowadays one of the most current issue is to increase the number of detectors. Superconducting microwave microresonators are low temperature detectors which are compatible with large-scale multiplexed frequency domain readout. We aim to adapt and further advance the technology of microresonator detectors to develop new devices applied to neutrino physics. More specifically, our purpose is the development of detector arrays for a direct and calorimetric measurement of the neutrino mass from Ho-163 electron capture (Q ~ 2-3 keV) . In order to achieve these goal, we need to find the best design and materials for the detectors. A recent advance in microwave microresonator technology was the discovery that some metal nitrides, such as TiN, possess properties consistent with very high detector sensitivity. We plan to investigate nitrides of higher-Z materials, for example TaN and HfN, that are appropriate for containing the energy of keV decay events, exploring the properties relevant to our detectors, such as quality factor, penetration depth and recombination time. In this contribution we present the first results obtained from our TiN detectors.Speaker: Mr Marco Faverzani (Università di Milano-Bicocca and INFN Milano Bicocca)
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Fine-grained nuclear emulsion as higher resolution tracking detectorNuclear emulsion is a kind of photographic film and very high resolution tracking detector. We propose the directional dark matter search project with the nuclear emulsion. It is possible to make the large mass detector which sensitive to direction . However, solid tracking detector is very difficult to detect the nuclear recoil tracks induced by dark matter because the track length in solid becomes less than 1 micron. This length cannot be detected even with the standard nuclear emulsion. Here, we developed the fine-grained nuclear emulsion as new detector. As the fine-grained nuclear emulsion has the resolution of less than 1 micron, it is possible to detect the nuclear recoil tracks. In addition, the new technique to read out the very short length tracks was also developed. In this talk, I will report the R&D status of fine-grained nuclear emulsion technique, the directional dark matter search project with nuclear emulsion and other application.Speaker: Dr Tatsuhiro Naka (Nagoya University)
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From SNO to SNO+: the multiple upgrades of the neutrino experimentSNO+ is a multi-purpose neutrino experiment in construction in the deepest underground laboratory: SNOLAB, Canada. It succeeds to the SNO experiment by replacing heavy water by liquid scintillator, thus lowering the sensitivity threshold to a lower energy. Loading the liquid scintillator with O(t) of Nd will enable the search for neutrinoless double beta decay with an expected sensitivity to the effective neutrino mass of 100-200 meV after 3 years. SNO+ also aims at studying the pep and CNO solar neutrinos, detect geo-, reactor and possibly supernova neutrinos. After introducing these physics goals, I cover the key upgrades from SNO to SNO+ that will allow, using the same infrastructure, to build a very different and versatile experiment. These upgrades concern all aspects of the experiment. The internal acrylic vessel containing the liquid scintillator must be cleaned, and also held down to make up for its buoyancy in the surrounding water shield. The electronics and DAQ system underwent significant changes, allowing for a redesigned trigger and larger data rate capacity. An underground purification plant will ensure that all the liquids of the experiment will reach and maintain a very high level of radiopurity. I'll also discuss in detail the calibration programme that has been redeveloped for SNO+ and must at all time keep in mind these radiopurity requirements.Speaker: Dr Gwenaelle Lefeuvre (University of Sussex)
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ICARUS T-600 and the status of LAr TPCThe ICARUS-T600 detector at LNGS laboratory is the largest Liquid Argon TPC (LAr-TPC) operating in an underground laboratory. Its calorimetric resolution and topology reconstruction capabilities permit a wide physics program, which goes from the study of neutrino oscillation on CNGS neutrino beam to nucleon decay searches. Atmospheric as well as solar neutrinos are also a case of study. A complete review of the last two years data taking will be given, pointing out detector efficiency and event reconstruction. The complete reconstruction of some events will be shown, proving the particles identification, as well as energy measurement capabilities of the LAr technology. A particular emphasis will be given to the ongoing detector’s upgrade. These upgrades are aimed at enhancing trigger efficiency in the energy range of nucleon decay and atmospheric neutrinos, by exploiting the detection of deposited charge into the trigger system. Finally, the results of the analysis of the CNGS neutrino events will be presented, including both the measurement of the hadronic and electromagnetic deposited energy and the muon momentum measurement via multiple scattering.Speaker: Mr Daniele Dequal (PD)
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Measurement of cosmic ray air showers using radio-detection techniques at the Pierre Auger ObservatoryThe measurement of radio signals from air showers is studied in detail with the Auger Engineering Radio Array (AERA) at the site of the Pierre Auger Observatory in Argentina. The first stage of AERA is in operation since autumn 2010 and consists of 23 autonomous radio-detector stations. The design of the stations including the radio antennas, the electronics system and the communications system is presented. In the next 12 months AERA will grow to a size of 150 stations covering an area of 20 km2. First physics results and improvements for this next stage of AERA will be discussed.Speaker: Dr Matthias Kleifges (Karlsruher Institut für Technologie (KIT) - IPE)
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Particle Trackers Based on Thick 1~mm and 0.7~mm Scintillating Fibres Readout by a Multi-anode PhotomultiplierThis talk will describe prototype particle tracking detectors constructed at LNF with thick 1~mm and 0.7~mm plastic scintillating fibres with a 64 channel Hamamatsu H7600 flat-panel multi-anode photomultiplier readout. Cosmic ray tracks from an array of 11 gas-filled drift tubes were matched to signals in the scintillating fibres in order to measure the resolution and efficiency of tracks reconstructed in the fibre-based tracker. Resolutions better than 0.250~mm have been found for the 1~mm fibre detector and better than 0.150~mm for the 0.7~mm detector. Measurements of the number of photoelectrons detected plus cross-talk will also be shown. A GEANT4 detector simulation was also developed to compare cosmic ray data with Monte Carlo results and will be discussed. Using the parameters measured in this experimental setup, modified fibre tracker designs are suggested to improve resolution and efficiency in future prototypes to meet modern detector specifications.Speaker: Dr Blake Leverington (LNF)
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Prospect for Charge Current Neutrino Interactions Measurements at the next CERN neutrino facility.In the last few years the experimental results on neutrino/antineutrino oscillations at Short-Baseline (SBL) have shown a tension with several phenomenological models. The recent and carefully recomputed antineutrino flux from nuclear reactors has further increased this tension suggesting the need of a better study of the neutrino physics at SBL. In this paper we present a proposal for two magnetic spectrometers designed to measure the momentum and charge of the leptons produced in Charged Current (anti-)neutrino interactions at the future CERN neutrino facility. The spectrometers are the natural complement of a large LAr detector used as a target. The magnetic spectrometers have been designed in order to measure the charge and momentum of the muons in wide energy range, from few hundreds MeV, using a 0.3T magnetic field in air, up to several GeV measuring the bending and range of the muon in a large RPC instrumented 1.5 T iron dipolar magnet. The RPC are operated in streamer mode and digitally readout. The bending of the muon in the magnetic field in air is measured using RPC detectors in streamer mode with 1 cm wide strip with analog readout. The paper presents the design of the two spectrometers with the foresee performances in termsof charge mis-identification, muon momentum measurement and sensitivity of the experiment, in conjunction with a LAr detector and as a stand-alone experiment, to the oscillation parameters.Speaker: Dr Eduardo Medinaceli Villegas (PD)
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QA/QC During the Construction of a Modular Neutrino Detector, NOvAA 15 kTon detector is being built at Ash River, MN to record particle interactions from neutrinos generated in a 700kW beam located 810 km away at Fermilab, in Chicago, IL. Assembly of this massive PVC detector is tracked via an enterprise level software system (Java EE) designed to ensure high quality construction. Each of the dozen client stations which are located throughout the detector hall track one of inventory, testing, assembly, filling, and outfitting tasks using a bar code scanner system coupled to a central database. Business logic is injected throughout to ensure procedures and to restrict failed processes. Remote monitoring and reporting is provided via a web-interface. A crew of forty will work in either of two ten hour daily shifts, four days per week through 2014 when the installation of the NOvA Far Detector is scheduled to for completion. A similarly designed Near Detector will be built in parallel to NuMI beam upgrades at Fermilab which begin later this year. In this talk the NOvA QA/QC system being deployed at Ash River will be described. Reference: http://www.umn.edu/~demuth/nova/Speaker: Dr David DeMuth (University of Minnesota, Crookston)
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R&D for the EXO-GAS experiment to search for neutrinoless double beta decayThe EXO collaboration is searching for neutrinoless double beta decay using 80% of isotopically enriched xenon (136Xe) to probe its Majorana nature and measure its mass. A 100 kg liquid xenon detector is currently running at WIPP. EXO is also conducting R&D on a high pressure xenon gas detector using natural xenon in the pressure range of 1 to 10 atm. This technique may offer superior energy resolution than a liquid xenon detector and facilitate track reconstruction. To enhance energy resolution, the high pressure xenon detector will use electroluminescence light. Detection of primary scintillation light in the detector will provide reconstruction of the absolute position of the charge along the drift coordinate (T0) for totally contained events. Achieving good energy resolution requires low concentration of electronegative impurities in the medium and, therefore, needs to exploit robust and reliable purification techniques. Another opportunity offered by the gaseous detector may be to detect Ba++. Ba++ ions could be transported by high electric fields in the gas to a nozzle, extracted them into a very low pressure region and detected in order to separate signal events from radioactive background. The status of the EXO-GAS experiment, its detector design, construction, Ba++ ions identification, gas handling system, purification, and gas analysis purity system will be presented.Speaker: Kirill Pushkin (Department of Physics and Astronomy, University of Alabama)
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RingLaser as gyroscopeRing-Lasers are commonly employed as gyroscope, since they measure angular velocity for the Sagnac Effect. The range of applicability is very wide: from aircraft guidance, to geodesy and geophysics. The large ring G in the Laser Ranging station of Wettzell (Baviera) has obtained the accuracy of fractions of prad/s, close to the one required to provide a tool for general relativity test. In particular an underground experiment has been proposed, G-GranSasso, which can measure the gravitomagnetic effect of the Earth (Lense-Thirring effect) with 1% accuracy in few years of data taking. The ringlaser will be described in details, reporting the most recent progresses obtained with the large ring G in Wettzel (16m perimeter ) and with our middle size prototype G-Pisa (5.4 m perimeter).Speaker: Dr Angela Dora Vittoria Di Virgilio (INFN - Pisa)
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Segmented high-purity germanium detectorsSegmented high-purity germanium detectors have been developed for a variety of experiments. The segmentation is used to augment the excellent energy resolution of such a device with spatial information to disentangle event topologies. Several performance aspects of true-coaxial segmented detectors are discussed, especially the effects of axes orientation and the problem of events close to the surfaces of the detector. A teststand and Monte Carlo tools developed to study such effects are introduced. The simulation tools can also be used to design novel detectors, such as segmented point-contact detectors. A selected design is presented and discussed.Speaker: Mr Oleksandr Volynets (Max-Planck-Insitute for Physics)
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Status report of the GERDA experiment Phase IPhase I of GERDA, aimed at investigating neutrino-less double beta decay of 76Ge, is active at LNGS since November 2011. For the first time in a physics experiment, 8 (enriched) bare coaxial Germanium detectors are operated since months immersed in liquid Argon, acting as shield against external radiation and as cooling medium; the cryostat is surrounded by a tank containing ultra-pure water, equipped with photo multiplier tubes to veto the residual cosmic muons. Front-end readout electronics consists of cryogenic charge sensitive preamplifiers with resistive feedback, designed to cope with the peculiar conditions of the GERDA experiment (radio-purity, long and resistive cables, etc.), followed by a digital acquisition system based on continuously running analog to digital converters. Dedicated signal processing techniques are finally applied to extract the information of interest (energy, time, baseline level and noise, etc.) The presentation will report on the current status of the GERDA experiment Phase I, focusing on Ge detectors performance in terms of energy resolution, stability over time, counting rate and related issues.Speaker: Dr Stefano Riboldi (Universita' di Milano - INFN Milano)
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Study of a Muon Veto Cherenkov Detector for the XENON1T ExperimentXENON is a dark matter direct detection experiment, consisting of a time-projection chamber (TPC) using xenon in double phase as sensitive detector medium. The XENON project is currently taking dark matter data at the Gran Sasso Underground Laboratory (Italy) with the XENON100 experiment (100 kg scale mass of target volume) devoted to explore the spin-indipendent elastic WIMP-nucleon scattering cross section at the sensitivity in the order of ~10$^{-45}$ cm$^2$. In parallel to the operation of XENON100 an intensive R&D program for the next generation experiment (of ton scale mass) of the XENON project, XENON1T, is currently taking place. XENON1T will have a goal to reduce the background by two orders of magnitude compared to XENON100, pointing to a sensitivity in the order of 10$^{-47}$ cm$^2$. In order to achieve this background level the employment of a passive shield is not sufficient and it must be complemented with an active system able to veto the underground residual muon flux. In this study we optimized this device consisting of a Cherenkov detector based on a water tank (~10m high and ~10m in diameter) equipped with photomultipliers (PMTs) of 8 inch diameter. The study has been carried out with a series of Monte Carlo simulations, based on the toolkit GEANT4, that showed the possibility to reach very high detection efficiencies in tagging the passage of both the muon and the shower secondary particles coming from the interaction of the muon in the rock.Speaker: Dr Serena Fattori (INFN - LNGS)
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Study of Linearity and Internal Background for LaBr3(Ce) Gamma-Ray Scintillation DetectorCerium-doped lanthanum bromide, LaBr3(Ce), crystal is the latest among the family of scintillation counters and shows same attracting properties for $\gamma$ spectroscopy that makes it a suitable solution for security, medical, geophysics and high energy physics applications. Among these properties are good density (5.1 g/cm$^3$), brightness (>65000 photon/MeV), time resolution and excellent energy resolution (<3% FWHM at $E_\gamma$=662 keV). LaBr3(Ce) crystal could become an interesting alternative to HpGe detectors. LaBr3(Ce) exhibits a proportional light yield response to $\gamma$-ray energy. Often this property is hampered at higher energies (>5 MeV) by instantaneous current limitation of PMT: fast and bright can have drawbacks for high energy applications. Very good linearity was seen up to 2 MeV. LaBr3(Ce) has also relatively high intrinsic radiation background due to naturally occurring $^{138}$La radioisotope. A good use of LaBr3(Ce) requires an accurate determination of the self activity, particularly when low background is required or when events are collected at extremely low trigger rates (both situations are the usual standard in the case of underground nuclear astrophysics experiments where we plan to test the LaBr3(Ce) crystal). Although $^{138}$La background is entirely below the energy of 1500 keV, additional background was seen in the region between 1500 and 2750 keV. The impact of internal background on energy resolution and linearity is discussed.Speaker: A. Lavagno (Politecnico di Torino and INFN Torino)
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Study of rare alpha decays with scintillating bolometersThe direct detection of rare alpha decays is very challenging, as detectors like gas counters or semiconductors can not achieve a sufficient sensitivity to study these processes. The background suppression against beta and gamma decays, which is a crucial issue for the disentanglement of the alpha peak, can be easily obtained by means of scintillating bolometers. These detectors can be sketched as a main bolometer plus a light detector. The energy measured by the main bolometer, that acts as an almost perfect calorimeter, is independent of the nature of the particle. However, the scintillation yield of alpha particles is significantly lower that the one of electrons of the same energy. Therefore, the simultaneous measurement of the scintillation light allows to identify the nature of the interacting particle and to reject the background due to electrons, providing a very high sensitivity on the alpha decay. We present the results obtained using this technique in the study of $^{209}$Bi, $^{204}$Pb, $^{206}$Pb and $^{208}$Pb decays. For the first time, the $^{209}$Bi alpha decays to the ground and to the first excited states were unambiguously observed in a BGO scintillating bolometer. A PbWO4 crystal was analyzed in the framework of the optimization of the light detectors for the LUCIFER experiment. Thanks to this measurement, the rare decays of the lead isotopes were studied with an unprecedented sensitivity. No signal was detected, providing a lower limit on the half life of these isotopes.Speaker: Laura Cardani (ROMA1)
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Surface induced background in CUOREBolometers are very promising detectors for neutrinoless Double Beta Decay (0$\nu$DBD) searches because of their excellent energy resolution, the high detector efficiency and a wide choice of different materials used as absorber. In order to further improve the sensitivity achievable, in recent years many studies have been done in order to understand and thereby reduce the radioactive background. The current model of the background in the 0$\nu$DBD region assumes that it is due mainly to degraded $\alpha$'s from surface contaminations of materials faced to crystals. This model is derived from the Cuoricino experience (the first step towards CUORE) and it is mainly based on the study of coincident events between TeO$_2$ bolometers since conventional techniques haven't enough sensitivity to study the very low level of surface contaminations reached. In order to reach the ability to identify the nature of the background observed in all the TeO$_2$ bolometric tests and then confirm the background model, a very accurate measurement with BGO scintillating bolometers was performed. Results obtained with this technique and details on the surface induced background in the bolometric technique will be presented.Speaker: Dr Luca Gironi (MIB)
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The AMS-02 Silicon Tracker: After one Year in SpaceThe Alpha Magnetic Spectrometer (AMS-02) is a high-energy physics experiment operating on the International Space Station since May 19th 2011. It measures the different components of cosmic rays to search for primordial antimatter and annihilation products of dark matter. With its large acceptance and at least 10 years of operation, AMS-02 will measure more than $10^{10}$ charged particles in the GV-TV rigidity range. The tracking device consists of 7 planes of Silicon in the bore of a permanent magnet (0.14T) and of 2 planes at the ends of the detector. It measures the rigidity and charge sign and identifies the ion species by dE/dx. The tracker is composed by 2264 double-sided Silicon sensors (72x41mm$^2$, 300 $\mu$m thick) assembled in 192 units, for a total of 200.000 read-out channels. The status of the AMS-02 tracker and its operation, after first months of data taking in space, will be presented, as well as its performances and potentialities.Speaker: Prof. Divic Rapin (DPNC, University of Geneva)
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The ANTARES Neutrino TelescopeThe ANTARES Neutrino Telescope is the first operational Neutrino Telescope in the Mediterranean Sea. It has been completed in May 2008 and is meant to perform neutrino astronomy via a large three-dimensional array of photo-multiplier tubes. This presentation describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France, as well as the performance of the detector.Speaker: Alexandre Creusot (APC - Paris)
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The Jem-Euso mission to explore ultra high energy cosmic rays from spaceThe JEM-EUSO (Extreme Universe Space Observatory on-board of the Japanese Experiment Module on the ISS) mission has the primary scientific objective of doing astromony and astrophysics detecting extreme energy cosmic rays (EECRs), above 10$^{20}$ eV, measuring particle arrival directions and energies. This will extend the knowledge of the sources, spectra and composition of the cosmic rays beyond the so called Greisen-Zatsepin-Kusmin (GZK) cut-off, constraining the acceleration and emission models in that energy range. JEM-EUSO apparatus has beed designed to detect the UV photons (330-400 nm) emitted in the shower produced by the EECR interaction with the atmosphere. Using the Earth as a target, JEM-EUSO is designed to detect, during the five year of the planned lifetime, more than 1000 events having an energy greater than 7x10$^{19}$ eV. This will be possible thanks to a super-wide-field of view (60 degree) telescope of about 2.5 m looking downward from the ISS to the night sky. Three fresnel lenses will compose the optics block that will focus the UV photons onto a focal surface, housing 4932 multi anode photomultiliers. The JEM-EUSO mission is the joint effort of institutions from 13 countries; it is planned to be launched in the 2017, using an H2B rocket, transferred to ISS by means of an H2 Transfer Vehicle (HTV) and attached to the Exposure Facility of the Japanese Experiment Module (JEM). The detector description and design perfomances will be presented.Speaker: Dr Francesco Saverio Cafagna (INFN - Bari)
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The KM3NeT photonic readout and data acquisition systemFor the KM3NeT neutrino telescope a novel optical network has been designed for data transfer and communication between the on-shore control room and optical sensors off-shore at distances up to 100 kilometers. The implementation relies on sensor technologies using a FPGA and photonic components and a 10 Gb/s optical network for readout, data acquisition and communication. Much functionality has been migrated to shore, thus allowing for easy access to the system during the long lifetime of the telescope. Timing calibration is an integral part of the network architecture providing an event timing integrity with less than 1 ns. Although developed for use in the deep-sea, the concept of the system can be used in other experiments. We will present the design and test results of the data acquisition system and the network architecture.Speaker: Prof. Herbert Loehner (KVI)
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The multi-PMT Optical Module for KM3NeTKM3NeT, the future deep-sea neutrino telescope of multi-cubic km size, is being designed to search for high energy neutrinos originating from galactic and extragalactic sources. The neutrinos can be detected by collecting Cherenkov light emitted from relativistic charged secondary particles caused by the interaction of neutrinos with the medium surrounding the detector. To collect the Cherenkov light, a digital optical module (DOM) containing an array of 31 3-inch diameter photomultiplier tubes (PMTs) has been designed as a promising alternative to a DOM containing one 10-inch diameter PMT. The main advantage is to reduce the environmental background by requiring local coincidences between neighboring photo sensors and to provide a homogeneous photon acceptance. Optimum performance requires high collection efficiency at low dark noise, homogeneous photo-cathode response and excellent timing properties. We studied the response to single photo-electrons of newly developed 3-inch diameter PMTs from Electron Tube Enterprises Ltd. by illuminating various positions on the photo-cathode surface with picosecond-laser pulses. Results of these investigations indicate good photo-cathode homogeneity, low dark noise on the sub-kHz level, and an average transit-time spread below 2 ns. The mechanical setup of the multi-PMT DOM and the electronic configuration will be presented. The expected performance and the advantages of the multi-PMT DOM in the future KM3NeT detector will be discussed.Speaker: Prof. Herbert Loehner (KVI, University of Groningen)
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The new PVLAS apparatus for detection of vacuum magnetic birefringenceThe PVLAS experiment aims at the observation and measurement of the effect of magnetic birefringence of vacuum (MBV). This effect (predicted since long, but so far never observed directly) is the consequence of non linear terms present in the QED lagrangian. These terms result from vacuum fluctuations due to creation and annihilation of pairs of virtual charged particles and antiparticles. Because of MBV an initially linearly polarized laser light beam acquires an ellipticity when it traverses a region with a magnetic field oriented perpendicularly to its direction of propagation. The MBV effect is extremely small and a first generation version of the PVLAS experiment has been able to establish only an upper limit. We describe here the new PVLAS apparatus, whose design features far better nominal performances for sensitivity, duty-cycle, noise suppression, signal validation and calibration. The apparatus is in construction at INFN-Ferrara, it uses a 4.8 m long granite optical bench, two rotating permanent dipole magnets (each with length L=94 cm, bore diameter φ=2 cm and B2L=11tesla2meter), an ellipsometer under UHV with a high finesse Fabry-Perot cavity (for expansion of the optical path), heterodyne technique for signal over background enhancement, Cotton-Mouton effect for amplitude calibration and dephasing of the two magnets by 90 degrees for direct zero measurement.Speaker: Ugo Gastaldi (LNL)
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The Time Of Flight Detector of the AMS-02 Experiment on the International Space Station, Operations and Performances in Space.The Alpha Magnetic Spectrometer AMS-02 has been installed in May 19th 2011 on the International Space Station, where it will detect cosmic rays for the next decades. AMS-02 with its accurate measurements up to the TeV scale will contribute to our knowledge of the Universe providing the most sensitive search for the existence of primordial anti matter and indirect search for dark matter. The Time Of Flight (TOF) detector of the AMS-02 experiment provides the trigger to the AMS detector, the time of flight and the absolute charge measurements. The flight operations and the performances of the TOF in Space will be presented.Speaker: Dr Veronica Bindi (INFN/University of Hawaii at Manoa)
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PID and Photo Detectors
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Significantly Improved Lifetime of Microchannel-Plate PMTsThe PANDA experiment at the new FAIR facility at GSI will perform charmonium spectroscopy and search for gluonic excitations using a high luminosity antiproton beam. The main components of the particle identification system will consist of DIRC (Detection of Internally Reflected Cherenkov Light) detectors residing inside a magnetic field of up to 2 Tesla. The most attractive sensors to detect the Cherenkov photons are multi-anode microchannel-plate (MCP) photomultipliers (PMT) which allow single photon detection with excellent performance inside B-fields. The drawback of MCP-PMTs until recently was their limited lifetime which mainly arises in a rapidly decreasing quantum efficiency of the photo cathode at high photon rates. However, in the latest models of PHOTONIS (XP85112), Hamamatsu (R10754X), and BINP different techniques are applied to reduce the aging effects. We are currently performing lifetime measurements for these new types of MCP-PMTs by simultaneously illuminating all improved tubes with the same photon rate. This should allow a fair comparison of the lifetime for all investigated MCP-PMTs and possibly a judgement on the best technique for an enhancement of the lifetime. In this paper performance measurements will be discussed with a special focus on extensive aging tests. The lifetime improvements in comparison to the older MCP-PMT models are more than an order of magnitude based on an extracted anode charge of ~2 C/cm$^2$.Speaker: Dr Albert Lehmann (Universität Erlangen-Nürnberg)
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Progress on development of the new FDIRC PID detectorWe present a progress status of a new concept of PID detector called FDIRC, intended to be used at the SuperB experiment, which requires $\pi/K$ separation up to a few GeV/c. The BaBar experiment has used very successfully the DIRC PID detector (DIRC = Detector of Internally Reflected Cherenkov light). The original DIRC had one weak point: its huge photon camera, filled with 6,000 liters of ultra-pure water, was sensitive to electromagnetic and neutron background. Therefore we have exchanged this simple pinhole camera at the heart of the DIRC detector into a focusing camera with sophisticated, solid fused-silica optics, while shrinking it to 1/25th its former size and increasing its speed by a factor of ten. The new detector is called FDIRC (Focused Detection of Internally Reflected Cherenkov light). Each of the 12 FDIRC Photon cameras will have 48 H-8500 MaPMTs, providing excellent timing capability for single photons ($\sigma_{TTS}$~140ps). It was also necessary to implement new front-end electronics with much higher timing precision (σElectronics ~100ps), higher hit rate capability (few MHz hit rate per pixel), and small dead time (< 5% at 1MHz rate). These improvements will compensate for the increase in luminosity (×100) and background between the two generations of experiments. A full scale FDIRC prototype module covering 1/12 of the barrel azimuth is nearing completion, and will be tested soon in the cosmic ray telescope (CRT) at SLAC with 3D tracking using muons.Speaker: Dr Jerry Vavra (SLAC)
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Pulse Shape Analysis with scintillating bolometersAmong the detectors used for rare event searches, bolometers are very promising because of their favourable properties. However, up to now, the possibility to identify the interacting particle, and thus to greatly reduce the background, can be fulfilled only with a double read-out (e.g. heat and scintillation light). This double read-out could greatly complicate the assembly of a huge, multi-detector array. The possibility to recognize the interacting particle through the shape of the thermal pulse is then clearly a very interesting opportunity. Detailed analyses of the signal time development in macro-bolometers built with scintillating crystals showed that it is possible to distinguish between $\beta$/$\gamma$ and $\alpha$ particle interaction (i.e. the main source of background for 0$\nu$DBD experiments based on the bolometric technique). Results of pulse shape analysis of signals from several bolometers with absorbers of different composition (CaMoO$_4$, ZnMoO$_4$, ZnSe, ...) are presented and the pulse shape discrimination capability of such detectors is discussed. An explanation of this behaviour, based on the energy partition in the heat and scintillation channels, is also presented.Speaker: Dr Luca Gironi (MIB)
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coffee break
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CSPAD-140k - a versatile detector for LCLS experimentsWith the successful operation of three 2.3 megapixel, 120Hz readout rate, hybrid pixel array detectors at the Linac Coherent Light Source (LCLS), the SLAC detector group is now exploring further applications based on the same detector platform. These megapixel cameras are based on the Cornell-SLAC hybrid Pixel Array Detector (CSPAD). One of the first spin-off detectors based on the proven CSPAD platform is the CSPAD-140k: a 140 kilopixel detector, with an active area of ca. 4x4cm$^2$ and four ASICs, in a small, inexpensive and easy-to-deploy package. The CSPAD platform is developed around the CSPAD ASIC with 36 kilopixel of 110x110 $\mu$m$^2$ size. Important characteristics of the CSPAD such as room temperature operation, 14bit on chip digitization with a purely digital data interface, and scaling modularity, make it an effective choice for designing detector variants which are optimized for a range of experiments and applications. Improvements on the ASIC operation derived from the experience at LCLS will be discussed. Another relevant component of this platform is the support electronics in the camera head, which has been optimized in the new implementation of the 140K. In addition, the LCLS-DAQ system allows for easy integration of several data formats as well as different data sources and handles the readout of multiple detectors into one single experiment-database. Examples of applications and performance figures of the CSPAD-140k operated at LCLS will be shown.Speaker: Sven Herrmann (SLAC National Accelerator Laboratory)
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Quantum well Structures for multi band photon detectionQuantum well (QW) structures are planar objects in which electrons are confined in one dimension. Compound semiconductors can be used to fabricate QWs with several combinations of barrier and well materials, allowing for a tuning of the electron band gap down to 0.8 eV. Preliminary experiments carried out on such an InGaAs / InAlAs QW indicate that these devices are very valuable in multi band photon detection. In addition and depending on the external circuitry internal charge amplification mechanism can be applied for very low signal levels. Moreover, the high mobility of the charge carries allows the design of very fast photon detectors with response times in the pico second range and below. In this contribution we present primary results obtained with a segmented QW detector that allowed monitoring simultaneously the intensity and the position of pulsed or continuous photon beams over an extended spectral range. Two versions of the read-out electronics have been applied: charge integration with 1 ms frame rate and 20 bit dynamics and a system based on wide bandwidth (5GHz) radiofrequency electronics chain, able to analyze fast photon pulses. For both readout schemes, position encoding is obtained by the centroid method. Although the primary application of the QWDs are envisaged in the field of free electron lasers and ultra bright synchrotron light sources the devices could be used in combination with table-top lasers and be exploited in other fields of photonics.Speaker: Dr Ralf Hendrik Menk (Sincrotrone Trieste)
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First tests of a RICH detector consisting of a matrix of CsI coated Thick GEMsIn the framework of the ALICE VHMPID project we have built a RICH detector prototype consisting of a matrix of six triple CsI coated TGEMs each of them having an active area of 10x10cm$^2$. As a radiator in first tests we used C$_5$F$_{14}$ in order to correctly compare the TGEM efficiency with the CsI-MWPC efficiency which we used as a reference. One triple TGEM has been placed behind the liquid radiator with the aim to detect the beam particles whereas the other five have been positioned around the central one, at a distance to collect the Cherenkov photons. In this report, we present the results of a series of exhaustive laboratory tests of this prototype carried out using UV light and electrons from $^{90}$Sr: the TGEM geometry optimization, the gas optimization, gas gain measurements in various conditions , the identification of the spark-less zone of the TGEM operation while detecting single photoelectrons and MIPs simultaneously, an evaluation of the CsI quantum efficiency, TGEM efficiency mapping with high position resolution, operational stability with time etc. The main focus, however, will be on first promising results of tests with a beam of charged pions and their preliminary analysis. The achieved results prove the feasibility of building a large area Cherenkov detector consisting of a matrix of TGEMs. We believe that such detectors represents an attractive option for the ALICE RICH upgrade detector which is under studySpeaker: Prof. Guy Paic (Instituto de Ciencias Nucleares, UNAM)
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PID and Photo Detectors - Poster Session
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A Charged Particle Identification Detector in the Forward Region of SuperBNew generation flavor factories like SuperB require very good charged particle identification. In SuperB, the barrel region is covered by a new detector based on the successful BaBar DIRC – the FDIRC, see separate contribution at this conference. To extend this excellent coverage down in polar angle, an additional detector has been designed for the forward region. Thin enough to fit between the drift chamber and the calorimeter endcap, it is made of 12 fused silica tiles arranged perpendicular to the beam axis and covering 30 degrees in azimuth each. Charged tracks crossing this area create Cherenkov photons. Part of this light is trapped by total internal reflection and propagates until the tile outer radius where it is detected by fast photon detectors. Both the photon timing and position are recorded and the pi/K separation is provided by the analysis of the photon distribution in this two-dimensional space. In order to achieve a 3 sigma separation up to 3 GeV/c, an excellent timing is needed, given the short path length (2 meters). This ambitious goal requires both fast detectors and new ultra-fast electronics (few ps accuracy), developed jointly by the LAL Orsay and the CEA/IRFU. A prototype using a MCP-PMT coupled to two fused silica radiator bars has been tested in the SLAC Cosmic Ray Telescope. We review the results achieved and present the next steps required to have this detector become part of the SuperB baseline, such as potential applications outside SuperB.Speaker: Dr Nicolas Arnaud (LAL-Orsay)
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EIGER characterization resultsEIGER is the next generation single photon counting x-ray detector developed at Paul Scherrer Institut for synchrotron based applications. It is a hybrid silicon pixel detector that features a 75x75 $\mu$m$^2$ pixel size, a high maximum frame rate capability of ~22 kHz (independent on the detector size), double buffered storage for continuous readout and a negligible dead time between frames of ~3 $\mu$s. Characterization and performance measurements have been done on several single chip detector systems, produced with chips coming from two different lots, both with a lab x-ray source and at the Swiss Light Source. Results on the detector calibration, electronic noise, threshold dispersion, minimum selectable energy threshold, maximum detectable incoming photon flux and maximum frame rate will be presented. Furthermore, radiation endurance tests with doses up to ~150 Mrad in the sensor and ~60 Mrad in the chip will be shown. These tests prove that the chip is fully functional and suited for multi-chip modules and larger multi-module detectors. An EIGER module is constructed from a ~4x8 cm$^2$ monolithic sensor bump-bonded to 4x2 readout chips, thus resulting in a 0.5 Mpixel detector. Several modules can be tiled together to form large area detectors and a 16 Mpixel system is already planned. The first X-ray images and characterization results of a fully working module assembled with its complete readout electronics will be also presented.Speaker: Dr Roberto Dinapoli (Paul Scherrer Institut)
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Evidences of Cerenkov light from a TeO$_2$ CrystalBolometers have proven to be good detectors to search for rare processes because of their excellent energy resolution and for their extremely low intrinsic background. The CUORE experiment, that aims at studying neutrino-less double beta decay, is building a detector made of 988 TeO$_2$ crystals, 0.750 kg each, kept at a temperature of 10 mK. In this kind of experiments, the capability of discriminating the signal produced by the alpha particles emitted by the natural radionuclides contaminating the detector represents an important aspect for the background reduction. One possibility for obtaining such a discrimination is provided by the detection of the Cerenkov light which, at the low energies of the natural radioactivity, is emitted only by electrons and not by alpha particles. The results of measurements of the Cerenkov light yield of TeO$_2$ at room temperature are shown. The signals produced by cosmic rays in the crystal are readout on two opposite faces by two PMTs. They show rise and decay times of few nanoseconds, typical of Cerenkov light. When the crystal is rotated in the direction that allows the Cerenkov photons to reach directly one PMT, this detects three times more light than the other one. These results represent the first clear indication that Cerenkov light is the main, if not even the only, component of the light signal in a TeO$_2$ crystal and it opens the possibility to make large improvements in the performance of experiments based on this kind of materials.Speaker: Mr Nicola Casali (INFN Laboratori Nazionali del Gran Sasso)
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KLOE-2 High Energy Tagger DetectorIn order to have access to the reaction $e^+e^- \to e^+e^- \gamma\gamma$ in the energy region of the phi meson production, new detectors along the (DAFNE) beam line have to be installed in order to detect the scattered $e^+e^-$. The HET detector is used for measuring the deviation of leptons from their main orbit by determining their position and timing so to tag gg physics events and disentangle them from background. The HET detectors are placed at the exit of the DAFNE dipole magnets, 11 m away from the IP, both on positron and electron arm. The HET sensitive area is made up of a set of 28 plastic scintillators. A dedicated DAQ electronics board based on a Xilinx Virtex-5 FPGA have been developed for this detector. It provides a MultiHit TDC with a time resolution of the order of 500 ps and the possibility to acquire data any 2.1 nsec, thus allowing to clearly identify the correct bunch crossing. First results of the commissioning run are presented.Speaker: Dr Dario Moricciani (ROMA2)
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New bi-dimensional SPAD arrays for Time Resolved Single Photon ImagingTime resolved imaging up to the single photon sensitivity is one of the most ambitious and important goals of photonics. In the last decades the time correlation analysis has been fundamental for the study of many scientific topics. Actually it has performed only by using the information of few points in the image. The implementation of such devices based on SPADs (Single Photon Avalanche Diodes) technology, has been recently proposed. The key point for this aim is the read-out strategy; it should be easy, in order to read a great number of elements, and able to address the information of each individual sensor, in order to get its time response. The simplest strategy is to address each diode, with a consequent requirement of a great number of channels, n$^2$ for a square matrix of n x n diodes. We proposed an alternative solution, initially based on the signals collection from both anode and cathode of the same diode [1]. Signal extracted from anode is used to determine the row position while the cathode signal for the column position. The rows x columns strategy require a number of reading channels of 2n instead of n$^2$. In respect to the original idea, several improvements have been performed (signal collection, technology, etc.). In this contribution we present the new bi-dimensional array of SPADs for imaging applications, realized in collaboration with the FBK–Trento (Fondazione Bruno Kessler).Speaker: Dr Rosaria Grasso (UNICT)
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Operation of proportional counters under high gas gain, high working gas pressure in mixed field of radiation.Gas gain is one of the main parameter of proportional counter. It was measured that this value depends on type of detected radiation and for beta particle is higher by (6-8)% than for X-rays. Over some value of current flowing threw the counter (Ic-critical current) the reduction in gas gain due to space charge defined by the time of evacuation of positive ions is observed. The value of Ic for different counter geometry and different mixture pressure was measured. It limits the rate capability of the detectors. Above some value of gas gain (Ac - critical value of gas gain) non-proportionality due to self inducted space charge effect is observed, avalanche size exceeds Reather's limit. The value of Ac was measured as function of working gas pressure for different counter geometry. The stable performance of proportional counters uned high gas gain and high working gas preasure is very crucial for detectors working at harsh condition of LHC. Results of systematic measurements of above values will be presented.Speaker: Dr Stefan Koperny (AGH, University of Science and Technology, Faculty of Physics and Applied Computer Science)
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Particle ID, position and timing measurement with scintillating fibers readout by SiPMsThe silicon photomultiplier (SiPM) is a recent and established evolution of the avalanche photodiode (APD). This device is particularly appropriate for use in scintillation detection because of its high sensitivity, high quantum efficiency, and insensitivity to magnetic field (up to 4 T). Excellent time and energy resolution in addition to small size and high efficiency are crucial for applications at high rate and low photon production. An active target for the MEG experiment based on very thin scintillating fibers readout by SiPM is considered. The tool should provide a very precise measurement of the muon decay vertex and its timing, with a consequently improvement on the positron momentum and angular variable resolutions into the MEG experiment. A particle ID can be performed to distinguish between positrons and muons. High rate can be sustained and applications on beam monitoring are also considered. Muon beam rate (the highest on the world), profile and spot can be measured.Speaker: Dr Angela Papa (Paul Scherrer Institut)
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Particle identification using the time-over-threshold measurements in straw tube detectorsIn the PANDA experiment, identification of charged particles in momentum region below about 1 GeV/c will be based on the measurement of energy losses in the central straw tube tracker. In order to make a choice between the charge integration and the time-over-threshold (TOT) techniques for the energy loss measurement, we performed tests of a prototype straw detector read out with a new front-end ASIC equipped with both analog and digital output. A very good performance of the TOT in a wide range of energy losses was observed. Results of tests agree with GARFIELD simulations of the straw tube response convoluted with transfer function for the front-end electronics. In the present contribution, the prototype module containing pressure stabilized straw tubes and the architecture of the front-end ASIC will be described and the results of the TOT measurements and simulations will be presented.Speaker: Sedigheh Jowzaee (Institute of Physics, Jagiellonian University, Krakow, Poland)
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Photodetector time resolution : from single photons to saturationThe time resolution of photon detection systems is important for a wide range of applications in physics and chemistry. It impacts the quality of time-resolved spectroscopy of ultrafast processes and has a direct influence on the best achievable time resolution of time-of-flight detectors in high-energy and medical physics. For the characterization of photon detectors, it is important to measure their exact timing properties in dependence of the photon flux and the operational parameters of the photodetector and its accompanying electronics. We report on the timing of different types of photodetectors, i.e. SiPMs, dynode PMTs and MCP-PMTs, in dependence of their bias voltage, electronics threshold settings and the number of impinging photons. We used ultrashort laser pulses at 400nm wavelength with pulse duration below 200fs. We focus our studies on different types of SiPMs (Hamamatsu MPPC S10931-025P, S10931-050P and S10931-100P) with different SPAD sizes (25$\mu$m, 50$\mu$m and 100$\mu$m) coupled to the ultrafast discriminator amplifier NINO. We show that for the SiPMs, an optimum in the time resolution regarding bias and threshold settings can be reached. For the 50$\mu$m type, we achieve a single photon time resolution of better than 180ps sigma, and for saturating photon fluxes better than 10ps sigma.Speaker: Mr Stefan Gundacker (CERN)
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Progress on the Development of a Silicon-Carbon Nanotube PhotodetectorThe properties of Carbon Nanotubes (CNT), the new allotropic status of carbon discovered in 1991, have been widely investigated in all possible application field. This new material in fact can be easily obtained chemically by CVD (Chemical Vapour Deposition) as a layer of nanotubes growth on a wide variety of materials. When growth on a semi conductive silicon surface, CNT create a semiconductor heterojunction with peculiar photoresponsivity properties. We studied this heterojunction with the purpose to realize a large UV sensitive photocathode with high quantum efficiency in a large wavelength range from UV to IR. Results obtained up to day allowed us to build a new kind of photodetector very cheap, stable and easy to manage. Recently this new device has been proposed as one of candidates for the beam monitor system of Super B. In this talk we will report on recent improvements and performances of this detector.Speaker: Carla Aramo (INFN - Napoli)
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Progress on THGEM-based photon detectors for COMPASS RICH-1New Cherenkov photon detectors are being developed for the upgrade of COMPASS RICH-1. The detectors are based on the use of THGEMs, arranged in a multilayer architecture, where the first layer is coated with a CsI film, acting as a reflective photocathode. The response of single layer THGEMs with various geometries and different conditions was extensively studied and photon detector prototypes were built, tested in laboratory and operated during test beam runs. Efficient detection of Cherenkov photons has been obtained, with typical gains of 100,000 and time resolution better than 10 ns. The motivations for the COMPASS RICH-1 upgrade and the status of the R&D project will be presented. The main challenges related to the construction of large area THGEM-based photon detectors and their use on RICH counters will be discussed.Speaker: Fulvio Tessarotto (TS)
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Study of H-8500 MaPMT for the FDIRC detector at SuperBWe present the status of studies of the Hamamatsu H-8500 Multi-Anode Photomultiplier. This device will be used for the FDIRC Particle Identification detector of the SuperB experiment (FDIRC = Focused Detector of Internally Reflected Cherenkov light) – see FDIRC contribution at this conference. The H-8500 MaPMT has been chosen for its excellent single photon timing capabilities and its highly pixilated design. We present results of (a) timing study, (b) gain uniformity, (c) single photoelectron detection efficiency uniformity, (d) cross-talk, (e) details of pulse height spectra.Speaker: Dr Fabio Gargano (INFN - Bari)
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The large-angle photon veto system for the NA62 experiment at CERNThe branching ratio (BR) for the decay $K^+\to\pi^+\nu\bar{\nu}$ is a sensitive probe for new physics. The NA62 experiment at the CERN SPS will measure this BR to within about 10\%. To reject the dominant background from channels with final state photons, the large-angle vetoes (LAVs) must detect photons with energies as low as 200 MeV with an inefficiency of less than $10^{-4}$, as well as provide energy and time measurements with resolutions of $\sim$10\% and 1~ns for 1 GeV photons. The LAV detectors make creative reuse of lead-glass blocks recycled from the OPAL electromagnetic calorimeter barrel. We describe the mechanical design and challenges faced during construction, the development of front-end electronics to allow simultaneous time and energy measurements over an extended dynamic range using the time-over-threshold technique, and the development of an in-situ calibration and monitoring system. Our results are based on test beam data collected using prototypes of the LAV detectors.Speaker: Paolo Massarotti (Naples University & INFN)
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The MICE beamline instrumentation for a precise emittance measurementThe International Muon Ionization Cooling Experiment (MICE) will carry out a systematic investigation of ionization cooling of a muon beam, for the future Neutrino Factory and the Muon Collider. As the emittance measurement willbe done on a particle-by-particle basis, a sophisticated beam instrumentation is needed to measure both particle coordinates and timing vs RF in a harsh environment due to high particle rates, fringe magnetic fields and RF backgrounds. A PID system, based on three time-of-flight stations (with resolutions up to 50 ps), two Aerogel Cerenkov counters and a KLOE-like calorimeter (KL) has been constructed and has allowed the commissioning of the MICE muon beamline in 2010. It will be followed in 2012 by an Electron Muon Ranger to determine the muon range at its downstream end and later by two tracker detectors to trace incoming particles inside two high-field superconducting solenoids. Detector performances will be shown and their use for the beamline characterization fully illustrated.Speaker: Mr Christopher Heidt (University of California Riverside)
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Vacuum Silicon PhotoMultipliersSilicon PhotoMultipliers (SiPMs) are arrays of inverse polarized diodes operating in Geiger mode with a gain of 10$^5$-10$^6$, comparable with that of PMTs, thus showing single-photon sensitivity and excellent photon-counting capability. SiPMs show many advantages over PMTs, such as higher quantum efficiency, lower operation voltages and insensitivity to magnetic fields, however their main drawback is represented by their small sensitive surface. In order to overcome this limit our group has suggested a solution consisting in an innovative design for a modern hybrid, high gain, silicon based Vacuum Silicon PhotoMultiplier Tube (VSiPMT) based on the combination of a SiPM with a hemispherical vacuum glass PMT standard envelope. In such a device photoelectrons emitted by the photocathode are accelerated and focused by an electric field towards a small focal area covered by the SiPM which therefore acts as an amplifier, thus substituting the classical dynode chain of a PMT. Before the realization of a first prototype of VSiPMT our group is carrying out a preliminary work consisting in the full characterization of the SiPM with a laser source, in the simulation of electron backscattering over SiPM surface and in the full characterization of the SiPM with an electron source. The first two phases have already been completed and their results have been presented: in this work we will describe the third phase, in particular describing our experimental apparatus and our preliminary results.Speaker: Daniele Vivolo (INFN - Napoli)
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