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This conference is the fifteenth of a series of meetings initiated in Tirrenia in 1980, and continued in Castiglione della Pescaia and La Biodola, devoted to review progresses on advanced detectors and instrumentation for physics experiments. The meeting is sponsored by the Istituto Nazionale di Fisica Nucleare (INFN), the Società Italiana di Fisica (SIF), the European Physical Society (EPS), the University of Pisa and the University of Siena.
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Transformative discovery in science is driven by innovation in technology. Our boldest undertakings in fundamental physics have at their foundation precision instrumentation. To reveal the profound connections underlying everything we see from the smallest scales to the largest distances in the Universe, to understand its fundamental constituents, and to reveal what is still unknown, we must invent, develop, and deploy advanced instrumentation. The 2020 European Strategy for Particle Physics requested that ECFA organize a roadmap developed by the community to balance the detector R&D efforts in Europe, taking into account progress with emerging technologies in adjacent fields. The roadmap identified and described a diversified detector R&D portfolio that has the largest potential to enhance the performance of the particle physics programme in the near and long term. This talk will outline some of the great questions in particle physics and how the ECFA Detector Roadmap addresses them.
Early Career Researchers (ECRs) play a crucial role in the LHC experiments. Since future experiments in particle physics can take decades to conceptualise, design, build and operate, today's ECRs are the leaders of tomorrow's experiments. The ECFA ECR panel conducted a survey about the training of ECRs in instrumentation. This poll however also yielded many other findings about issues of networking, recognition and diversity in instrumentation, that will as well be presented. The goal is to stimulate discussion about the needs of ECRs in instrumentation and what actions can be taken to help them.
The Belle II experiment at the SuperKEKB e+e- collider has started data taking in 2019 with the perspective of collecting 50ab-1 in the course of the next several years. The detector is working well with very good performance, but the first years of running are showing novel challenges and opportunities for reliable and efficient detector operations with machine backgrounds extrapolated to full luminosity. For this reason, and also considering that an accelerator consolidation and upgrade shutdown is being studied for the timeframe of 2026-2027 to reach the target luminosity of 6E35 cm-2s-1, Belle II has started to define a detector upgrade program to make the various sub-detectors more robust and performant even in the presence of high backgrounds, facilitating the SuperKEKB running at high luminosity. This upgrade program will possibly include the replacement of some readout electronics, the upgrade of some detector elements, and may also involve the substitution of entire detector sub-systems such as the vertex detector. The process has started with the submission of Expressions Of Interest that are being reviewed internally and will proceed towards the preparation of a Conceptual Design Report. This paper will cover the full range of proposed upgrade ideas and their development plans.
With proton-proton collisions about to restart at the Large Hadron Collider (LHC) the ATLAS detector will double the integrated luminosity the LHC accumulated in the ten previous years of operation. After this data-taking period the LHC will undergo an ambitious upgrade program to be able to deliver an instantaneous luminosity of $7.5\times 10^{34}$ cm$^{-2}$ s$^{-1}$ allowing to collect more than 3 ab$^{-1}$ of data at $\sqrt{s}=$14 TeV. This unprecedented data sample will allow ATLAS to perform several precision measurements to constrain the Standard Model Theory (SM) in yet unexplored phase-spaces, in particular in the Higgs sector, a phase-space only accessible at the LHC. The price to pay to be able to collect such a rich data-sample is to upgrade the detector to cope with the challenging experimental conditions that include huge levels of radiation and pile-up events about a factor 5 higher than in the present condition. The ATLAS upgrade comprises a completely new all-silicon tracker with extended rapidity coverage that will replace the current inner tracker detector; a redesigned trigger and data acquisition system for the calorimeters and muon systems allowing the implementation
of a free-running readout system. Finally, a new subsystem called High Granularity Timing Detector that will aid the track-vertex association in the forward region by incorporating timing information into the reconstructed tracks. A final ingredient, relevant to almost all measurements, is a precise determination of the delivered luminosity with systematic uncertainties below the percent level. This challenging task will be achieved by collecting the information from several detector systems using different and complementary techniques.
This presentation will describe the ongoing ATLAS detector upgrade status and the main results obtained with the prototypes, giving a synthetic, yet global, view of the whole upgrade project.
After more than 15 years of successful data taking, the Pierre Auger Observatory started a major upgrade, called AugerPrime, whose main aim is the collection of new information about the primary mass of ultrahigh-energy cosmic rays (UHECRs), besides adding new indications on hadronic interactions at UHE.
The upgrade program includes: the installation of plastic scintillator detectors (SSDs) on top of each water-Cherenkov detector (WCD) of the surface array; new electronics to process signals from the WCD and the SSD with higher sampling frequency and enhanced resolution in amplitude; an extension of the dynamic range of measurement through an additional small photomultiplier tube in the water-Cherenkov tank; an array of underground scintillator detectors to measure the muonic component of extensive air showers; the deployment of a radio antenna atop each WCD.
After presenting the motivations for upgrading the Observatory, an overview of the detector upgrade is provided, together with the expected performances and the improved physics sensitivity. The first results from the data collected with the already upgraded AugerPrime stations are presented and discussed.
The LHCb Vertex Detector (VELO) will be upgraded for the LHC run-III to a pixel detector capable of 40 MHz full event readout and operation in very close proximity to the LHC beams. The thermal management of the system is provided by evaporative CO$_2$ circulating in micro-channels embedded within thin silicon plates. The VELO modules host 12 VeloPix ASICs with a total power consumption of up to 30 W. The implementation of an efficient and radiation hard cooling system is mandatory to remove the heat produced by the ASICs and keep the sensors below -20o.C and mitigate the radiation damage. The solution created is to use a cooling substrate composed of thin silicon plates with embedded micro-channels that allow the circulation of boiling CO$_2$. The direct advantages of this technique is the low and uniform material contribution, same thermal expansion coefficient that of the sensor-ASIC tiles, the radiation hardness of CO$_2$ and high heat transfer capacity. The fluidic connector to the substrate should be leak tight in order to withstand the operational pressures and be placed in vacuum. A flux-free connector soldering solution was developed which respects the planarity and the correct positioning required for the subsequent construction of a precise tracking system. The solder joint was tested for long term effects of creep and fatigue. Alternative solutions were pursued in parallel to the development of the micro-channels, based on 3D printed titanium tubes or on steel capillaries inside a ceramic substrate. However, the micro-channel evaporative cooling provides a better physics performance, due to the low material and no CTE mismatch. This talk will cover the key points of the micro-channels R&D which includes design optimisation, fabrication, robustness tests, cooling performance and the comparison with the backup options.
The ATHENA (A Totally Hermetic Electron-Nucleus Apparatus) detector is designed to deliver the full physics program of the Electron-Ion Collider (EIC) as set out for the EIC project approval (December 2019), providing the best possible acceptance, resolution, and particle identification capabilities. As an entirely new detector, ATHENA has been designed to accommodate all necessary subsystems without compromising on performance, while leaving room for future upgrades. Central to the proposal is a new, large-bore magnet with a maximum field strength of 3T. Particle tracking and vertex reconstruction are performed by a combination of next-generation silicon pixel sensors and state-of-the-art micro-pattern gas detectors. The combination of magnetic field strength and high resolution, low mass tracking technologies optimizes momentum resolution and vertex reconstruction. The large bore of the magnet allows for layered, complementary, state-of-the-art particle identification technologies. A novel hybrid imaging/sampling electromagnetic calorimeter is proposed for the barrel region of the detector, along with a high resolution crystal calorimeter in the electron-going direction. The hadron endcap has calorimetry, tracking and particle identification detectors that are optimized for high-momentum hadron identification and high-energy jet reconstruction. We have striven for hermeticity by closely integrating the far-forward and far-backward detectors with the central detector to achieve maximal kinematic coverage and to optimize the detection of particles at small scattering angles. Careful balance between choice of cutting-edge and mature detector technologies achieves the necessary detector performance while minimising risk and providing a cost-effective solution. Scalable modern technology choices assure optimum performance for multi-year operation from day one.
The ATHENA detector and its potentialities are reviewed in the frame set by the outcome of the EIC Call for Proposal Process, not yet known at the time this abstract is submitted, but which will be announced at the beginning of March 2022.
The design of a feasible multi-TeV Muon Collider facility is the mandate of the international Design Study based at CERN and is considered with great interest along the presently on-going US SnowMass process. The physics potential of such a novel future collider is overwhelming, ranging from discovery searches to precision measurements in a single experiment. Despite the machine-design challenges it is possible to reach the uncharted territory of 10 TeV center-of-mass energy or higher while delivering luminosity up to a few 10^35 cm^-2 s^-1.
The experiment design, the detector technology choices along with the reconstruction tools are strongly affected by the presence of the Beam Induced Background (BIB) due to muon beams decay products interacting at the Machine Detector Interface (MDI).
Full simulation studies at 𝒔 = 1.5 and 3 TeV, adopting the CLIC experiment technologies with important tracker modification to cope with BIB, are the starting point to optimize the detector design and proposing future dedicated R&Ds. Present results and future steps will be discussed.
FASER is a new experiment designed to search for new light weakly-interacting long-lived particles (LLPs) and study high-energy neutrino interactions in the very forward region of the LHC collisions at CERN. The experimental apparatus is situated 480~m downstream of the ATLAS interaction-point aligned with the beam collision axis. The FASER detector includes four identical tracker stations constructed from silicon microstrip detectors. Three of the tracker stations form a tracking spectrometer, and enable FASER to detect the decay products of LLPs decaying inside the apparatus, whereas the fourth station is used for the neutrino analysis. The spectrometer has been installed in the LHC complex since March 2021, while the fourth station was also installed since November 2021. FASER will start physics data taking when the LHC resumes operation in early 2022. This talk describes the design, construction and testing of the tracking spectrometer, including the associated components such as the mechanics, readout electronics, power supplies and cooling system.
In the High Luminosity era, the Large Hadron Collider (LHC) will be upgraded to deliver instantaneous luminosities up to $5 \times 10^{34} \ \mathrm{cm^{-2}s^{-1}}$, five times more than the original design value. In order to maintain performance of the Compact Muon Solenoid (CMS) experiment under these conditions, ME0 is one of the three new muon sub-detectors being added, along with GE1/1 and GE2/1, which use the triple Gas Electron Multiplier (GEM) technology. ME0 is designed to cover the forward region of 2.0<$|\eta|$<2.8, thus improving muon reconstruction at high background rates by supplementing other overlapping muon subsystems up to $|\eta|$=2.4, while also extending the acceptance for the first time to $|\eta|$=2.8. The readout electronics for ME0 must be designed to deal with high data rates and be sufficiently radiation hard to operate so close to the beamline. The Optohybrid (OH) board for ME0, which reads out data from the front-end VFAT3b ASICs, has therefore been designed to operate without an FPGA (unlike GE1/1 and GE2/1) to ensure radiation hardness. It will use the radiation-hard CERN designed lpGBT ASIC and high bandwidth optical links at 10.24 Gb/s, thus also providing the benefit of high data rates. The backend system will be based on the ATCA standard. The design and development status of the readout electronics for ME0 will be presented, along with recent results from integration tests performed using the first prototypes.
The full optimization of the design and operation of instruments whose functioning relies on the interaction of radiation with matter is a super-human task, given the large dimensionality of the space of possible choices for geometry, detection technology, materials, and data-acquisition and information-extraction techniques, and the interdependence of the related parameters. On the other hand, enormous potential gains in performance over standard, "experience-driven" layouts are in principle at reach if an objective function fully aligned with the final goals of the instrument is maximized by a systematic search of the configuration space.
The stochastic nature of the involved quantum processes make the modeling of these systems an intractable problem from a classical statistics point of view, yet the construction of a fully differentiable pipeline and the use of deep learning techniques may allow the simultaneous optimization of all design parameters.
In this presentation I will lay down the plans for the design of a modular and versatile modeling tool for the end-to-end optimization of complex instruments for particle physics experiments as well as industrial and medical applications that share the detection of radiation as their basic ingredient, and show results of the study of a muon tomography use case, to highlight the potential of this approach.
The MoEDAL Apparatus for Penetrating Particles (MAPP) was recently approved by CERN's Research Board to take data during LHC's Run-3. This detector extends the physics reach of the MoEDAL detector, the LHC's first dedicated search experiment that was built to detect highly ionizing avatars of new physics. The MAPP detector will concentrate on the search for feebly (electromagnetically) interacting particles (FIPs) such as milli-charged particles. The MAPP detector will also provide sensitivity to very long-lived neutral and charged particles.
For the Phase 2 upgrade, the CMS experiment foresees the installation of a MIP Timing Detector (MTD) to assign a precise timestamp to every charged particle up to pseudorapidity |$\eta$| = 3, empowering the CMS detector with unique and new capabilities. The target timing resolution of MTD, 40 ps per track, will help reduce the challenging pile-up conditions expected at the High-Luminosity LHC down to current LHC levels. To match the requirements on radiation tolerance and occupancy, the forward region of the MTD, 1.6 < |$\eta$| < 3, will be equipped with silicon low-gain avalanche diodes (LGADs) coupled to the Endcap Timing Read Out Chip (ETROC), currently under development. We will present the current status of LGAD sensor testing, their qualification from beam tests, bench measurements, and the performance of the final ETROC design. Finally, we will discuss the challenges and the road map necessary to achieve timely installation of ETL.
Throughout ATLAS Run-2, the LUCID detector, that is located close to the beampipe on both side of the interaction point, has been the reference luminosity detector, providing the online and offline luminosity measurement with high stability and a preliminary uncertainty of about 1.7%.
For the high-luminosity LHC, new beampipe equipment and more demanding luminosity precision requirements and LHC beam conditions are expected. The detector will therefore be completely redesigned, exploiting both new and tried-and-tested technologies. Prototype detectors for the new running conditions and technologies have been developed and installed and will be tested during the upcoming LHC Run-3. These consist of a PMT-based detector, which uses the quartz window as Cherenkov medium and is positioned further from the beampipe, a low-rate PMT detector, located in the shadow of one of the ATLAS shieldings, and the fiber detector, in which fiber bundles are used as Cherenkov-light emitter and transmitter and that are calibrated with an innovative hybrid LED and radioactive-source system. In these prototypes, the behavior of new Hamamatsu R1635 and R7459 PMT’s will be evaluated.
In this contribution, the motivations for the detector redesign and a description of the LUCID upgrade are illustrated, as well as a detailed account of the preliminary tests performed with the prototypes, including PMT characterization and a study of the fiber degradation under irradiation.
In the frame of the progress towards the High Luminosity Program of the Large Hadron Collider at CERN, the ATLAS and CMS experiments are boosting the preparation of their new environmental friendly low temperature detector cooling systems. This paper will present a general overview of the progress in development and construction of the future CO2 cooling systems for silicon detectors at ATLAS and CMS (trackers, calorimeters and timing layers), due for implementation during the 3rd Long Shut Down of LHC (LS3). We will describe the selected technology for the primary chillers, based on an innovative transcritical cycle of R744 (CO2) as refrigerant, and the oil-free secondary “on detector” CO2 pumped loop, based on the evolution of the successful 2PACL concept. Different detector layers will profit from an homogenized infrastructure and will share multi-level redundancy that we will describe in details. The technical progresses achieved by the EP-DT group at CERN over the last years will be discussed in view of the challenges and key solutions developed to cope with the unprecedented scale of the systems. We will finally present how mechanics- and controls-related problems have been addressed via a vigorous prototyping programme, aiming at cost- and resource-effective construction of the final systems, which is starting now.
The LUXE experiment aims at studying high-field QED in electron-laser and photon-laser interactions, with the 16.5 GeV electron beam of the European XFEL and a laser beam with power of up to 350 TW. The experiment will measure the spectra of electrons, positrons and photons in expected ranges of 10^-3 to 10^9 per 1 Hz bunch crossing, depending on the laser power and focus. These measurements have to be performed in the presence of low-energy high radiation-background. To meet these challenges, for high-rate electron and photon fluxes, the experiment will use Cherenkov radiation detectors, scintillator screens, sapphire sensors as well as lead-glass monitors for backscattering off the beam-dump. A four-layer silicon-pixel tracker and a compact electromagnetic tungsten calorimeter with GaAs sensors will be used to measure the positron spectra. The layout of the experiment and the expected performance under the harsh radiation conditions will be presented. Beam tests for the Cherenkov detector and the electromagnetic calorimeter were performed at DESY recently and results will be presented. The experiment received a stage 0 critical approvement (CD0) from the DESY management and is in the process of preparing its technical design report (TDR). It is expected to start running in 2024/5.
With its increased number of proton-proton collisions per bunch crossing, track
reconstruction at the High-Luminosity LHC (HL-LHC) is a complex endeavor. The Inner
Tracker (ITk) is a silicon-only replacement of the current ATLAS tracking system as part of
its Phase-II upgrade.
It is specifically designed to handle the challenging conditions resulting from the increase
in luminosity.
Having undergone a series of layout optimizations, the ITk pixel detector now features a
reduced radius of its innermost barrel layer, among other changes. This contribution will
discuss the evolution of the ITk design, alongside its impact on the tracking performance
and some higher-level object reconstruction and identification.
To ensure stable data-taking conditions, it is critical to manage the rate at which ITk data is
being read out. ITk information is read out for bunch crossings selected by the first level
trigger with an expected rate of 1 MHz. Recent calculations on the expected data rates at
the design frequencies will be presented, and handles to ensure rates stay below the
bandwidth thresholds will be discussed.
The CMS silicon strip tracker with its more than 15000 silicon modules and 200m2 of active silicon area will resume operation after 3 years of Long Shutdown 2 in the Spring of 2022. We present the status of the detector before the start of the LHC Run 3 data taking. The performance of the detector during the Run 2 data taking is presented including the signal-to-noise ratio, fraction of bad components in the detector, hit efficiency, and single hit resolution. We discuss projections of the detector performance during Run 3. In addition the change of detector parameters with increasing radiation damage is reviewed.
The tracking performance of the ATLAS detector relies critically on its 4-layer
Pixel Detector. As the closest detector component to the interaction point, this detector is subjected to a significant amount of radiation over its lifetime. By the end of the LHC proton-proton collision RUN2 in 2018, the innermost layer IBL, consisting of planar and 3D pixel sensors, had received an integrated fluence of approximately Φ = 9 × 1014 1 MeV neq/cm2.
The ATLAS collaboration is continually evaluating the impact of radiation on the Pixel Detector. During the LHC long shutdown 2 LS2 dedicated data taking of cosmic rays have been taken at this purpose.
In this talk the key status and performance metrics of the ATLAS Pixel Detector are
summarised, and the operational experience and requirements to ensure
optimum data quality and data taking efficiency will be described, with special emphasis to radiation damage experience. A quantitative analysis of charge collection, dE/dX, occupancy reduction with integrated luminosity, under-depletion effects, effects of annealing will be presented and discussed, as well as the operational issues and mitigation techniques adopted during the LHC Run2 and the ones foreseen for Run3.
The Electromagnetic Calorimeter (ECAL) barrel of CMS experiment at CERN is made of 36 Supermodules, each consisting of 1700 lead tungstate scintillating crystals. Each Supermodule weighs 2.7 tonnes and is a highly sensitive and fragile object. The Supermodules, 18 Supermodules on each side of CMS barrel, were successfully inserted inside the Hadronic Calorimeter (HCAL) barrel of CMS in 2007 with a dedicated insertion tool called “Enfourneur”. The movements of the Enfourneur are controlled by a fine adjustment system for the Supermodule insertion and extraction. During the Long Shutdown 3 foreseen in 2026, the Enfourneur will be used to extract the Supermodules for their electronics upgrade in view of the HL-LHC future runs and to insert the Supermodules again in CMS.
Based on the past operations, modifications on the current Enfourneur have been implemented in order to improve and facilitate the functionalities, in compliance with the up-to-date international standards concerning machinery safety and CERN internal applicable rules. This work was carried out through several stages and iterations covering a complete design study, FEA simulation within the scope of Eurocode 3, installation of the modifications, and validation tests. The modified Enfourneur fulfills all the intended technical and safety requirements.
In this paper, a review of the Enfourneur functionalities, the applied modifications, and the performed validation tests will be presented.
At the Mainz Microtron MAMI, the technique of high-resolution spectroscopy of decay-pions in strangeness electroproduction has been established to extract $\Lambda$ ground state binding energies of light hyperfragments. In a first series of measurements, a $^9$Be target was used to determine the $^4_\Lambda$H binding energy with unprecedented precision in a momentum setting near 133 MeV/c. The current measurement employs a novel lithium target of 50 mm length and only 0.75 mm thickness to precisely determine the hypertriton binding energy in a 114 MeV/c setting.
The complex setup in the spectrometer hall comprises a pre-target beam-line chicane, a high-luminosity lithium target, two high-resolution pion spectrometers, one zero-degree forward spectrometer for strangeness tagging, one photon beam-line and one electron exit beam-line. The focusing magnetic spectrometers provide a high momentum resolution at the 10$^{-4}$ level over the momentum range of hypernuclear decay-pions, a large acceptance in both angle and momentum, good position and angular resolution in the scattering plane, an extended target acceptance, and a large angular range to optimally accommodate for different beam-target angles. A thermal imaging system controls the target alignment with respect to the beam. A recalibration of the pion spectrometers will be possible due to the precise beam energy determination with the undulator light interference method.
The experiment aims for a statistical and systematic error of about 20 keV and will run during the summer of 2022.
The Mu2e experiment at Fermilab will search for the Standard Model forbidden coherent conversion of a negative muon into an electron
in the field of an aluminum nucleus.
The calorimeter complements the tracking information, providing track-seeding and particle identification to help reconstruct the mono-energetic electron candidates. The calorimeter is based on 1348 undoped CsI crystals displaced in two donut-shaped staggered matrix disks.
Each crystal is read by two custom made arrays of UV-extended Silicon Photomultipliers (SiPMs).
The system is completed by a radioactive calibration source, a fast laser calibration system and the digitizing electronics\
The two SiPMs glued on a copper holder, two independent Front-End
Electronics (FEE) boards, coupled to each SiPM, and the guide for the calibration fiber needle form a Readout Unit (ROU).
The ROU holder has a size of approximately 34$\times$34$\times$70 mm$^3$ and consists of a copper bulk structure where 2 SiPM and readout boards are mounted, a fiber needle centering tube and a copper Faraday cage fastened with 4 custom stainless steel screws to a brazed cooling copper line.
There are 674 ROU packed next to each other, vertically staggered, per calorimeter disk.
From each ROU, 2 SiPM multiple cables and a fiberglass fiber depart towards different locations.
The very compact matrix of SiPM modules,
the multiplicity of services they need and the narrow space of accessing after installation,
complicates the manipulation of such modules in the experimental hall which could be necessary for maintenance.
This poster shows the conceptual mechanical design of a robotic arm
composed by a gantry structure for xyz positioning on the desired ROU
and equipped with custom-designed grippers to unscrew fasteners, un-clip connectors,
unscrew the fiber needle and pick up the module, in a dedicated sequence.
FASER, or the Forward Search Experiment, is a new experiment at CERN designed to complement the LHC's ongoing physics program, extending its discovery potential to light and weakly-interacting particles that may be produced copiously at the LHC in the far-forward region. New particles targeted by FASER, such as long-lived dark photons or dark scalars, are characterized by a signature with two oppositely charged tracks or two photons in the multi-TeV range that emanate from a common vertex inside the detector. The experiment is composed of a silicon-strip tracking-based spectrometer using three dipole magnets with a 20-cm aperture, supplemented by four scintillator stations and an electromagnetic calorimeter. The full detector was successfully installed in March 2021 in an LHC side-tunnel 480 meters downstream from the interaction point in the ATLAS detector. FASER is planned to be operational for the upcoming LHC Run 3.
In 2021 a test beam campaign was carried out using one of the CERN SPS beam lines to characterize and calibrate a subset of the FASER detector in preparation for physics data taking. Placed in the test beam was a FASER tracking station composed of spare ATLAS SCT modules, followed by a simple preshower system consisting of two-layers of tungsten and scintillator, and lastly a 3x2 stack of spare LHCb electromagnetic calorimeter modules. Beams of electrons with energies between 10 and 300 GeV, as well as high energy muons and pions, were scanned across the entire face of the setup. The performance of the detector components as measured in the test beam will be presented, including the calorimeter resolution, particle identification capabilities, and the efficiencies of the tracker and scintillators.
Lepton beam facilities at intensity frontiers open new opportunities for precision and BSM physics. Jefferson Lab currently hosts the CEBAF accelerator which delivers a 12 GeV high power electron beam (up to 1 MW) to run in parallel up to four fixed target experiments. The comprehensive physics program includes: nucleon and nuclear structure, hadron spectroscopy and physics beyond the SM. While the future Electron Ion Collider is being built at Brookhaven National Lab, JLab is considering an upgrade in intensity (up 2.5 MW) and energy (up to 24 GeV). The upgraded machine will be able to extend the current electron-scattering program to unexplored kinematical regions and add new capabilities including a polarized positron beam and high intensity secondary muon and neutrino beams. In this contribution I will give an overview of the physics opportunities, the status of the proposal, and plans for accelerator and detectors upgrades.
Magnetic and electric dipole moments of fundamental particles provide powerful probes for physics within and beyond the Standard Model. For the case of short-lived particles, these have not been experimentally accessible to date due to the difficulties imposed by their short lifetimes. The R&D on bent crystals and the experimental techniques developed to enable such measurements are discussed. An experimental test at the insertion region IR3 of the LHC is considered for the next few years as proof of principle of a future fixed-target experiment for the measurement of charm baryon dipole moments. The layout of the experiment, the instrumentation to be developed, and the main goals of the test are also presented.
The BRAND experiment aims at the search of Beyond Standard Model (BSM) physics via measurement of exotic components of the weak interaction. For this purpose, eleven correlation coefficients of neutron beta decay will be measured simultaneously. Seven of them: H, L, N, R, S, U, and V, are sensitive to the transverse polarization of electrons from free neutron decay. Coefficients: H, L, S, U, and V were never attempted experimentally before. The BRAND detection system is oriented for the registration of charged products of the beta decay of polarized, free neutrons. With the measurement of the 4-momenta of electron and proton, the complete kinematic of the decay will be determined. Moreover, the transverse spin component of the electron will be measured via Mott scattering which is a key factor to probe BSM weak interaction.
The electron detection system features both tracking and energy measurement capability. It is also responsible for the determination of the electron spin orientation. For the 3D tracking, a low density,
helium-based drift chamber of a hexagonal cell structure that is optimized for beta particles is used. The Mott polarimeter is an integral part of the tracker. It is realized by a thin Pb-foil as a Mott-scatterer installed inside the drift chamber and two plastic scintillators providing the trigger and energy of the scattered electrons.
A challenging aim of the detection of low-energy protons from the beta decay is performed with a system, which involves the acceleration and subsequent conversion of protons into bunches of electrons. These ejected electrons (~25 keV) from a thin LiF layer are finally registered in a position-sensitive thin plastic scintillator readout with the arrays of SiPMs.
(Full abstract in the attached PDF file)
After ten years of intense work, the two New Small Wheels (NSW) for the upgrade of the Atlas Muon Spectrometer are now installed in the experiment and ready for final commissioning and to collect data in LHC Run3, starting March 2022.
The NSW is the largest phase-1 upgrade project of ATLAS. Its challenging completion and readiness for data taking is a remarkable achievement of the Collaboration.
The two wheels (10 meters in diameter) replace the first muon stations in the high-rapidity regions of ATLAS and are equipped with multiple layers of two completely new detector technologies: the small strips Thin Gap Chambers (sTGC) and the Micromegas (MM). The latter, belonging to the family of Micro Pattern Gaseous Detectors (MPGD, for the first time used in such a large scale in HEP experiments. Each of the detector technology will cover more than 1200 m2 of active area.
The new system is required to maintain the same level of efficiency and momentum resolution of the present detector, in the expected higher background level in view of the ongoing series of LHC luminosity upgrades. As well as keeping an acceptable muon trigger rate with the same muon momentum threshold.
In this presentation the motivation of the NSW upgrade and the steps from construction to assembly and surface commissioning will be reviewed, with particular focus on the main challenges, the adopted solutions and measured performance of the system. First results will be reported from commissioning data and first cry in the experiment.
The small sensitive area of commercial silicon photomultipliers (SiPMs) is the main limitation for their use in many experiments and applications where large detection areas, low cost and power consumption are needed. Since capacitance, dark count rate and cost increase with the SiPM size, they are rarely found in sizes larger than 6 mm $\times$ 6 mm. Photo-Trap offers a low-cost solution to build SiPM pixels of a few cm$^2$ by combining a wavelength-shifter plastic (WLS), a dichroic filter and a standard commercial SiPM (not larger than 6 mm $\times$ 6 mm). Photo-Trap collects light over an area that can be $\sim10-100$ times larger than the area of a commercial SiPM, while keeping the noise, single-photoelectron resolution, power consumption and likely the cost of a single, small SiPM. We developed and characterized through laboratory measurements and simulations, four different proof-of concept pixels, the largest one being of 40 mm $\times$ 40 mm. These pixels are sensitive in the near UV and achieve an optical gain that goes from ~5 to ~15, depending on the areas if the WLS and the SiPM employed. In all pixels we measured a time resolution of ~3 ns or better. Photo-Trap could provide a solution to use SiPM technology in applications in which large collection areas, low cost and low noise are needed (e.g., optical wireless communication, free space quantum key distribution, Cherenkov detectors). Here we present the results of our laboratory measurements, Geant4 simulations of the pixel and we briefly discuss the some of the potential applications of Photo-Trap.
The Belle II Time-Of-Propagation (TOP) counter is a novel particle
identification detector based on the combined measurement of a
particle's time of flight, the propagation time of Cherenkov photons
it emits when crossing a thin fused silica bar, and their geometrical pattern.
The Cherenkov radiation is internally reflected to an array of micro-
channel-plate photomultipliers located at one end of the bars. The
photomultiplier signal is digitized by zero-deadtime waveform sampling
ASIC with time resolution of 20 ps. The waveform features like timing,
amplitude and integral are extracted online using a Xilinx FPGA-
ARM device. The single photo-electron time resolution of the readout
chain is better than 100 ps.
Similar devices have been proposed, but TOP is the only operational
detector of this kind at the moment.
We will describe the status of the detector hardware in its fourth
year of operations, the stability and quality of the time calibration,
the particle identification performance and we will present an outlook
for possible upgrades.
We present the development of a single-photon detector encapsulating the analog and digital front-end electronics and the connected data acquisition electronics.
This 'hybrid' detector is composed of a vacuum tube, transmission photocathode, micro-channel plate stack and a pixelated CMOS read-out anode encapsulating the analog and digital-front end electronics.
The detector will be capable of sustaining a rate of up to $10^9$ photons per second with simultaneous measurement of position and time.
This assembly will be able to reach $5$-$10~\mathrm{\mu m}$ position resolution and timing resolution of $o(10)~\mathrm{ps}$.
The detector will be highly compact thanks to the encapsulated front-end electronics allowing local data processing and digitization.
A dual-micro-channel plate chevron stack operated at low gain ($<10^4$) and treated with atomic layer deposition, allows a lifetime of $>20~\mathrm{C/cm^2}$ accumulated charge.
The pixelated read-out anode used is based on the Timepix4 ASIC designed in the framework of the Medipix collaboration.
This ASIC integrates an array of $512\times448$ pixels distributed with a $55~\mathrm{\mu m}$ square pitch over a sensitive area of $6.94~\mathrm{cm}^2$.
It features $50$-$70~\mathrm{e^{-}}$ equivalent noise charge, a maximum rate of $2.5~\mathrm{Ghits/s}$, and allows to time-stamp the leading-edge time and to measure the Time-over-Threshold (\textit{ToT}) for each pixel.
The pixel-cluster position combined with its ToT information allows to reach $5$-$10~\mathrm{\mu m}$ position resolution.
This information can also be used to correct for the leading-edge time-walk achieving a timing resolution of $o(10)~\mathrm{ps}$.
An FPGA-based data acquisition board, placed far from the detector, will receive the detector hits using $16$ links operated at $10.24~\mathrm{Gbps}$.
The data acquisition board will decode the information and store the relevant data in a server for offline analysis.
These performance will allow significant advances in particle physics, life sciences, quantum optics or other emerging fields where the detection of single photons with excellent timing and position resolutions are simultaneously required.
Large Area Picosecond Photodetectors (LAPPDs) are micro-channel based photosensors featuring hundreds of square centimeters of sensitive area in a single package and timing resolution on the order of 50 ps for a single photon detection. However, LAPPDs currently do not exist in finely pixelated 2D readout configurations that in addition to the high-resolution timing would also provide the high spatial resolution required for Ring Imaging CHerenkov (RICH) detectors. One of the recent LAPPD models, the so-called Gen II LAPPD, provides the opportunity to overcome the lack of pixellation in a relatively straightforward way. The readout plane of Gen II LAPPD is external to the sealed detector itself. It is a conventional inexpensive capacitively coupled printed circuit board (PCB) that can be laid out in a custom application-specific way for 1D or 2D sensitive area pixellation. This allows for a much shorter readout-plane prototyping cycle and provides unprecedented flexibility in choosing an appropriate segmentation that then could be optimized for any detector needs in terms of pad size, orientation, and shape. We fully exploit this feature by designing and testing a variety of readout PCBs with conventional square pixels and interleaved anode designs.
Data acquired in the lab with the LAPPD tile 97 provided by Incom will be shown using a laser system to probe the response of several interleaved and standard pixelated patterns. Results from a beam test at Fermilab Test Beam Facility will be presented as well, including world’s first Cherenkov ring measurement with this type of a photosensor. 2D spatial resolutions well below 1 mm will be demonstrated for several pad configurations. Future plans, including a direct demonstration of e/p/K/p separation by a proximity focusing RICH detector prototype with a LAPPD as a photosensor in a forthcoming beam test at Fermilab in summer 2022, will be discussed.
The DSSC camera was developed for photon science applications in the energy range 0.25-6 keV at the European XFEL in Germany. The first 1-Megapixel DSSC camera is available and is successfully used for scientific experiments at the “Spectroscopy and Coherent Scattering” and the “Small Quantum System” instruments. The detector is currently the fastest existing 2D camera for soft X-rays.
The camera is based on Si-sensors and is composed of 1024×1024 pixels. 256 ASICs provide full parallel readout, comprising analog filtering, digitization and data storage. In order to cope with the demanding X-ray pulse time structure of the European XFEL, the DSSC provides a peak frame rate of 4.5MHz. The first megapixel camera is equipped with Miniaturized Silicon Drift Detector (MiniSDD) pixels. The intrinsic response of the pixels and the linear readout limit the dynamic range but allow one to achieve noise values of ~60 electrons r.m.s. at 4.5MHz frame rate.
The challenge of providing high-dynamic range (~104 photons/pixel/pulse) and single photon detection simultaneously requires a non-linear system, which will be obtained with the DEPFET active pixels foreseen for the advanced version of the camera. This technology provides lower noise and a non-linear response at the sensor level.
We will present the architecture of the whole detector system with its key features. We will summarize the main experimental results obtained with the MiniSDD-based camera and give a short overview of the performed user experiments.
We will present for the first time the experimental results with complete sub-modules of the DEPFET camera which is in the final stages of assembly. Measurements obtained with full size sensors and the complete readout electronics have shown a mean noise of ~15 el. rms with MHz frame rate and a dynamic range more than one order of magnitude higher with respect to the MiniSDD camera.
Silicon Photo-Multipliers (SiPMs) have emerged as a compelling photo-sensor solution over the course of the last decade and due to their optimal operation at cryogenic temperatures and low radioactivity levels are the baseline photo-sensor solution for several next generation dark matter detectors.
SiPMs are the baseline photo-sensor solution for the Darkside-20k detector and thanks to their high timing resolution and photon detection efficiency will allow to achieve an excellent pulse shape discrimination discriminating electron recoil from nuclear recoil events.
To establish experimentally the effect of the timing resolution in the pulse shape discrimination for DarkSide-20k, a detailed characterisation study of the SiPM Single Photon Timing Resolution (SPTR) was carried out at Laboratori Nazionali del Gran Sasso (LNGS). More precisely we studied from room temperature down to 40 K the SiPM SPTR as a function of the over-voltage and for different wavelengths. The factors affecting the SPTR electronically are bandwidth and rise time which were also investigated to identify the quantities that can potentially improve the detector timing resolution. The SPTR was studied at different scales of integration of SiPMs in order to identify the key quantity that reduces the final detector SPTR with increasing photodetector readout area.
Photon Science X-ray Sources (PSXSs) are divided between Synchrotron Rings (SRs), and Free Electron Lasers (FELs), having either low (<200Hz) or high (>=1MHz) repetition rate. SRs and low-repetition-rate FELs are usually served by imagers capable of continuous readout up to a few k-frame/s; while high-repetition-rate FELs need dedicated detectors capable of M-frame/s, but only for short imaging bursts.
However, PSXSs are also being upgraded: SRs evolve towards diffraction-limited operation, expected to increase brilliance by 2 orders of magnitude and asking for proportionally faster (continuously-operating) imagers. Several high-repetition-rate FELs are considering Continuous Wave operation, which will marginally reduce the repetition rate (to a few 100kHz), but will make short imaging bursts no longer an option.
A common need emerges, to bridge the gap and to provide imagers able to operate continuously, at a frame rate of few 100k frame/s.
Our collaboration is developing such an X-ray imager: our goals include continuous operation in excess of 100 kframe/s, single-photon sensitivity at 12 keV, a full well of 10k photon/pixel/image, and a 100μm pixel pitch. A readout ASIC is being developed for this purpose, compatible to traditional Silicon Sensor (for our main energy range), high-Z sensors (for shorter wavelenghts), and sensors with built-in amplification (for soft X-rays).
ASIC architecture includes an adaptive-gain charge-integrator (on the experience of the AGIPD detector), a battery of on-chip ADCs (embedded in the pixel array) and a fast readout system (on the principle of the GWT-CC developed by Nikhef for Timepix4). These stages are pipelined to allow for continuous writing-reading.
Exploratory prototypes of the ASIC circuital blocks have been designed in TSMC65nm are presently under test.
We plan to develop the imager it in two phases, first targeting the continuous readout scheme and the frame rate target, and later aiming at extending dynamic range and reducing noise.
A typical gamma camera for full-body Single Photon Emission Computed Tomography (SPECT) employs a lead collimator and a scintillator crystal (∼ 50 x 40 x 10) cm$^3$. The crystal is coupled to an array of 50-100 photo-multiplier tubes (PMTs). The camera is shielded by a thick layer of lead, making it heavy and bulky. Its weight and size could be significantly reduced if replacing the PMTs by silicon photomultipliers (SiPMs). However, one would need a few thousands channels to fill a camera with SiPMs even with the largest commercially-available SiPMs of 6 x 6 mm$^2$. As a solution we propose using Large-Area SiPM Pixels (LASiPs) in SPECT, which are built by summing individual currents of several SiPMs into a single output. We developed a LASiP prototype that sums 8 SiPMs of 6 x 6 mm$^2$ (pixel area ∼2.9 cm$^2$ ) and built a proof-of-concept micro-camera holding 4 of those prototypes coupled to a NaI(Tl) crystal. We measured an energy resolution of ∼ 11.6 % at 140 keV and were able to reconstruct simple images of a $^{99m}$Tc capillary of 0.5 mm diameter with an intrinsic spatial resolution of ∼2 mm. The micro-camera was also simulated with Geant4 and validated with experimental measurements. To study the possibility of using (eventually larger) LASiPs in a full-body SPECT camera, we extended the simulations to a camera of 50 x 40 cm$^2$. We optimized the trigger and reconstruction settings for LASiPs summing 9, 16, 25 and 36 SiPMs (pixel area up to ∼13 cm$^2$ ). We found an intrinsic spatial resolution going from ∼2 to ∼6 mm depending on the pixel size and the simulated LASiP noise (dark counts, crosstalk) and were able to reconstruct images of phantoms. In the conference we will present the results of this study.
Sensors based on GaAs are of particular interest as X-ray detectors since they have several advantages over Si, like a wider bandgap (lower dark current) and higher atomic number (higher detection efficiency).
In recent years we have developed and have studied Separate Absorption and Multiplication Avalanche PhotoDiodes in GaAs designed explicitly for synchrotron and free electron laser, featuring multiplication layers based on superlattice with staircase structures.
Effects of doping level of the various layers, the number of multiplication steps and the role of the "separation layer" have been analyzed.
Here we present further studies concerning quantum efficiency and the possibility of working in a "non punch-through" regime.
Devices with different thicknesses of the absorption zone have been studied using synchrotron light, producing electrons in the absorption layer at variable distances from the multiplication zone, and the role of the interfaces in the loss of efficiency has been measured.
Then we analyzed the devices depositing an δ p-doped sub-monolayer of carbon atoms such as to achieve complete depletion of the multiplication region but not punch-through, and thin enough to allow most of the electrons produced in the absorption zone enter the multiplication zone. In this way, the efficiency is high and the absorption zone is never subjected to a field such as to induce unwanted charge multiplication or band-to-band tunneling.
Photon science with extended ultra violet (EUV) to soft X-ray photons generated by state of the art synchrotrons and FEL sources imposes an urgent need for suitable photon imaging detectors. Requirements on such EUV detectors include high quantum efficiency, high frame rates, very large dynamic range, single-photon sensitivity with low probability of false positives, small pixel pitch and (multi)- megapixels. Such characteristics can be found in few state of the art commercial detectors based on scientific CMOS (sCMOS), which have been recently developed for applications in the visible light regime. In particular back thinned sCMOS are suited for experiments in the photon energy range between 30 eV and 2000 eV, which requires vacuum operations.
In this contribution we describe the adaption of a commercial back illuminated sCMOS imager for soft X-rays in the energy range from 35 eV – 2000 eV. The sCMOS imager comprises 2048 x 2048 pixels with a pixel size of 6.5 µm x 6.5 µm. The sensor exhibits a full well capacity of 48 000 e- and a readout noise of 1.9 e- (rms) with a dynamic range of 88 dB. The integration time can be adjusted between 10 µs – 2 seconds. The maximum frame rate is given by 48 fps for the full frame. Vacuum compatibility has been obtained by sealing the carrier board of the sensor, which constitutes the barrier between vacuum and normal atmosphere, which allows to keep the entire readout and trigger electronics in air. At the moment a KF flange is utilized to attach the camera and subsequently sensor to the experimental vacuum chamber. Here we present the first measurements showing a very high quantum efficiency for energies between 100 eV and 2000 eV. Soft X-ray (spectral) imaging capabilities with single photon resolution have been assessed.
TRICK is a project funded by the INFN CSNV Young grant 2021. It will deploy an innovative 5D technique to provide incoming particles' 3D position, time, and ID information. The proposed idea is based on the well-known technology of GEM-based TPC together with conventional Aerogel proximity focussing RICH in one single box. Both TPC and RICH parts will be readout simultaneously and instrumented by the same TIGER ASIC, developed for the BESIII CGEM-IT detector. By combining information from both systems, the TRICK technique will improve the single instrumentation performance: precise time information will help the extraction of the TPC position, while the tracking will help the rings identification, by measuring the expected center, also in a magnetic field.
The TRICK-box prototype, instrumented with triple-GEM and Hamamatsu H12700 MA-PMT, aims to reach a spatial resolution of 100 microns, time resolution below 1 ns, and 3 sigma separation for pi/K up to 4 GeV.
In this poster, a presentation of the project will be presented, with a focus on the initial studies with the prototype, the preparation of the first cosmic stand, and the next steps.
Silicon Photo-Multipliers (SiPMs) are widely used as light detectors for the new generation of experiments dedicated to high energy physics. For these reason, we tested several recent devices from different manufacturers: Hamamatsu 13xxx and 14xxx series; Ketek; SensL ONsemiconductors; AdvanSid; Broadcom. Particular emphasis has been put on measurements of breakdown voltage, dark counts and dark current and gain, performed at different temperatures by means of a climatic chamber (F.lli Galli model Genviro-030LC) with a temperature range from -60 ◦C to +60 ◦C, housing the SiPM under test and of a cryo-pump with a cold head, allowing to scan the temperature from 300 K down to 50 K. In this way it was also possible evaluating the temperature coefficient of all models. Moreover, all devices have been successfully tested in a Liquid Nitrogen bath (77 K), having in mind possible applications to detectors for neutrino and dark matter searches using liquefied noble gases such as Xenon and Argon as a target medium. In this case, the thermal component of the noise decreases at low temperature, thus allowing the use of the device at higher overvoltage.
The organometal halide perovskites (OMHP) semiconductors are promising candidates for fast, sensitive and large area photodetectors. A gain in OMHP based detectors has been observed in several architectures, but usually in association with a slow time response. A model describing the underlying mechanics is still missing or at least incomplete. In this talk the state of art of the photo-detectors based on OMHP perovskites will be presented, and the activities carried on within the PEROV experiment as well. One goal of the PEROV project is to find out whether OMHPs exhibit an internal avalanche multiplication. Several CH3PbBr3 perovskite based devices have been developed, fabricated and characterized: film-based devices with 300 nm thickness and devices based on high quality single crystals with seeding techniques or with unconventional lithographic techniques, with thickness from microns to mm.
A 7.25 x 12.04 cm^2 Silicon Drift Detector (SDD) has been developed for the enhanced X-Ray Timing and Polarimetry (eXTP) mission of the Chinese Academy of Science, with a large contribution by a European consortium inherited from the ESA-M3 LOFT mission study. In the frame of the project X-Ray Observatories (XRO), active in the National Scientific Commission 2 of the INFN, we report the details of the qualification procedure to select from the mass production the 640 detectors that will equip the Large Area Detector (the eXTP instrument dedicated to the X-ray spectroscopy in the range 2-30 keV), with energy resolution below 240 eV FWHM at 6 keV during the entire mission duration of at least 5 years. This stringent requirement dictates the need to thoroughly verify the characteristics of each single detector before integration in the final layout. We describe the dedicated testing facilities that have been developed. We report on the detector selection criteria and test results obtained in the pre-series production.
The ABALONE is a new type of photosensor produced by PhotonLab with cost effective mass production, robustness and high performance. This modern technology provides sensitivity to visible and UV light, exceptional radio-purity and excellent detection performance in terms of intrinsic gain, afterpulsing rate, timing resolution and single-photon sensitivity. This new hybrid photosensor, that works as light intensifier, is based on the acceleration in vacuum of photoelectrons generated in a traditional photocathode and guided towards a window of scintillating material that can be read from the outside through a Silicon PhotoMultiplier (SiPM). In this contribution we present the extensive characterization of the ABALONE as a possible photosensor for future astroparticle physics experiments
The Mu3e experiment searches for a rare lepton flavor violating μ+ → e+e+e− decay and it aims at reaching an ultimate sensitivity of 10−16 on the branching fraction of the μ+ → e+e+e− decay, four orders of magnitude better than the current limit B(μ+ → e+e+e−) < 10−12. The experiment will be hosted at the Paul Scherrer Institute (Villigen, Switzerland) which delivers the most intense low momentum continuous muon beam in the world (up to a few ×10^8 μ/s).
In order to be sensitive to the signal at this so high level, to reject the background and to run at the intensity beam frontier excellent detector performances are needed.
We will report the R&D that has been performed presenting some of the prototypes of the scintillating fiber detector by defining the path for the final detector. These studies have been supported with detailed Monte Carlo simulations from the fiber through the photosensors up to the electronics and the data acquisition. The fiber detector is designed to detect minimum ionizing particles (m.i.p.) with a minimal amount of material (the detector thickness below 0.4 % of radiation length X0) with full detection efficiency, timing resolutions well below 1 ns, and spatial resolution of ≈ 100 μm. While expertise in scintillating fibers and SiPMs has been around for a while, this detector will be the first to match these demands. A very high detection efficiency (≥ 99%) and timing resolutions < 500 ps have been measured. The optical cross-talk between Aluminum coated fibers has been kept at a negligible level (< 1%), for which spatial resolutions < 50 μm are foreseen. The very good agreement between data and Monte Carlo simulation predictions will be also presented and discussed.
TORCH is a large-area time-of-flight (ToF) detector, proposed for the Upgrade-II of the LHCb experiment. The detector will provide charged hadron identification over the 2-20 GeV/c range to complement LHCb’s particle identification to lower momentum. To achieve this level of performance, a 15 ps timing resolution per track is required, given a 10 m flight distance from the LHC interaction point. TORCH utilizes a 1 cm thick quartz plate which, on the passage of a charged particle, acts as a source of prompt Cherenkov photons. The photons are propagated to the periphery of the plate via total internal reflection where they are focused by a cylindrical-mirrored surface onto an array of micro-channel plate photomultiplier tubes (MCPs).The MCPs record the position and arrival times of the Cherenkov photons which allows a correction for chromatic dispersion in the quartz. The MCPs are custom-developed with an industrial partner and give a 1 mrad precision on the photon trajectory; the anode of each MCP is finely segmented to give an effective granularity of 8 x 128 pixels over a 53 x 53 mm^2 square area. The MCP single-photon time resolution has been measured at around 50 ps in the laboratory, including the contribution from the TORCH customised electronics-readout system. A TORCH prototype module having a 125 x 66 x 1 cm^3 fused-silica radiator plate and housing two MCP-PMTs has been tested in a 8 GeV/c CERN test-beam. Single-photon time resolutions of between 70-100 ps have been achieved, dependent on the beam position in the radiator. The measured photon yields also agree with expectations. The performance approaches the ToF design goal for LHCb, considering that a fully-instrumented TORCH module will detect around 30 photons. Finally, the future TORCH R&D plans and the expected particle-identification performance at LHCb will be presented.
X-ray photon science at free-electron lasers (FEL) and synchrotron light sources supports diverse research spanning from medicine to solid-state physics. Detectors that are able to cope with the brilliance, repetition rate, and pulse duration of these X-ray sources are in high demand. The hybrid silicon pixel detector JUNGFRAU provides low noise and, simultaneously, high dynamic range, fast readout, and high position resolution. It is optimized for a photon energy range between $2$ keV and $16$ keV and can resolve single photons down to $\sim 1.5$ keV with a dynamic range of $10^4$ photons at $12$ keV. For this purpose, JUNGFRAU combines a charge-integrating architecture and three linear, dynamically switching gains per pixel. JUNGFRAU systems of various sizes (i.e. up to 16 megapixels to date) are operated at FEL and synchrotron facilities worldwide. The success of these systems promotes ongoing research to further improve the JUNGFRAU detector and make it applicable for photon science at the low and high-energy ends of the X-ray spectrum. For instance, the combination of the low-noise JUNGFRAU readout ASIC with inverse LGAD (iLGAD) sensors with thin entrance windows is expected to extend the sensitive range of the system down to $250$ eV.
In this contribution, we present the state of the art of current JUNGFRAU systems and discuss recent improvements. We cover measurement results of prototypes for low-energy X-ray detection and present an outlook on possible combinations of JUNGFRAU with high-Z sensor materials to facilitate experiments with high-energy X-rays.
A novel imaging technique for thermal neutrons using a fast-optical camera is presented. Thermal neutrons are reacted with Lithium-6 to produce a pair of 2.73 MeV tritium and 2.05 MeV alpha particles, which in turn interact in a thin layer of LYSO crystal scintillator to produce a localized flash of light. These photons are directed by a pair of lenses to a micro-channel plate intensifier, the optical camera, TPX3CAM is connected to the intensifier output. The setup is shown in figure 1 (attached).
The results from the camera are reconstructed through a custom algorithm. Each reconstructed neutron event is made up of several sub-clusters, each cluster represents a group of photons, which were produced by the photon multiplier from a single photon input. A neutron hit is calculated to produce 3-6 photons at the intensifier input. The background of this experiment consists of low energy beta particles and x-rays, which produces single photons. Figure 2 (attached) shows 3 groups of photons, which are relatively close to each other both spatially and temporally, this event was is determined as the result of a neutron hit.
In conclusion, this new optical neutron imaging technique allows remote and long-distance detection from the radiation source also magnifies the field of view of a detector by using an appropriate set of focusing lenses.
Due to their single-photon sensitivity and timing resolution, SiPMs are now the baseline solution for a large fraction of noble liquid experiments and medical imaging such as positron emission tomography, among others. Following this trend, digital SiPMs, or Photon-to-Digital Converters (PDC), are foreseen like the next generation of photon sensors. PDCs and SiPMs are both based on an array of Single-Photon Avalanche Diodes (SPAD) with the major difference that CMOS circuit is used to quench and read out the SPAD in the former compared to a passive resistor and an analog sum of each SPAD in the latter. PDCs offer major advantages over SiPMs due to the one-to-one SPAD-CMOS readout coupling. It enables control of the afterpulsing, improved timing resolution, disabling noisy SPADs, a single photon counting on a dynamic range equal to the number of SPAD in the array, to name a few.
Our team and collaborators are working to develop 3D PDCs, where a SPAD array is vertically integrated on a CMOS readout circuit with digital signal processing. In this contribution, the SPAD array developed by U. of Sherbrooke and Teledyne DALSA Semiconductor Inc (Bromont, Canada) will be presented in public for the first time. The structure of the SPAD array will be detailed. Measurements and wafer-level test setups will be presented and discussed.
In the forward end-cap of the Belle II spectrometer, the proximity focusing Ring Imaging Cherenkov counter with an aerogel radiator (ARICH) has been in operation since 2018. The single Cherenkov photons emitted from a double layer aerogel radiator are detected by 420 Hamamatsu hybrid avalanche photodetectors (HAPD) with 144 channels working in a perpendicular 1.5 T magnetic field. The sensor signals are digitized by a custom front-end ASIC and sent to the experiment acquisition system. The detector has shown a very reliable operation in several years of operation. 94% of channels are fully operational; there hasn’t been any significant degradation since the beginning. Although each HAPDs requires six different high voltages for the operation, the intelligent slow control and monitoring system supports the ARICH function. The ARICH runs almost without any human intervention, e.g., during the last run period, there has not been any significant downtime due to ARICH. A precise alignment and calibration of the detector and the quality assessment of the components before installation contributed to ARICH capabilities. The particle identification performance measured by $D^{\pm *}$ decays meets the design expectations: the kaon identification efficiency is above 96% in the wide momentum range from 0.5 to 4 GeV/c at a relatively low pion misidentification probability of 10%. The ARICH was designed to operate up to the nominal design luminosity of 8$\times10^{35} cm^{-2} s^{-1}$. Until then, the leak current of HAPDs will increase, causing the degradation of HAPD performance. Also, single event upsets will affect the electronics. We are implementing several new mitigation measures to ensure the ARICH functionality. For the operation beyond the design luminosity, we are studying different possible HAPD replacements: silicon photomultipliers and large area picosecond photon detectors.
We report on the calibration and performance of the TOF-Wall detector of the FOOT (FragmentatiOn Of Target) experiment. The experiment aims at measuring the fragmentation cross-section of 200–800 MeV/u carbon and oxygen ions impinging onto carbon and polyethylene targets for applications in hadrontherapy and radioprotection in space. The TOF system of the experiment is composed of a thin plastic scintillator, positioned in the upstream region of the experiment, and the TOF-Wall. This system allows the identification of the charge of each fragment by measuring the energy deposited in the TOF-Wall and the time of flight (TOF) between the two detectors. The TOF-Wall is composed of 20 + 20 plastic scintillator bars arranged on two orthogonal layers, coupled to silicon photomultipliers, covering an active area of 40 cm x 40 cm. The analog signals are digitized by the WaveDAQ system. The TOF-Wall detector was characterized by scanning its surface with 400 MeV/u oxygen ions, and by detecting the fragments produced by a carbon ion beam onto a graphite target. The results for the TOF-Wall timing performance with different impinging particles and the energy calibration of the detector will be reported in this contribution. A time resolution of 41 ps was obtained between the two layers of the TOF-Wall using 200 MeV/u carbon ions, corresponding to a contribution of about 20 ps to the time resolution of the TOF system. The energy resolution achieved with carbon ions was 4-5% when both layers are considered. The fragments produced by the C-C interactions were used to study the saturation of the plastic scintillator bars as a function of the released energy and of the impinging ions. The uniformity of the performance on the whole TOF-Wall area was also analyzed and will be discussed.
Single-photon detectors are a corner stone of many scientific experiments. While some require precise timing resolution under 100 ps, others need components to be radiopure and operational at noble liquid temperatures. To this end, the team at Université de Sherbrooke and their collaborators have been working on the development of a photodetection module. This module is comprised of Photon-to-Digital Converters (PDC) – an array of Single-Photon Avalanche Diodes (SPAD) vertically integrated on a CMOS readout circuit with digital signal processing where photon-to-bit conversion is performed. To match the coefficient of thermal expansion of silicon-based PDCs in cryogenic experiments, a silicon interposer was implemented. To manage and read out the PDCs, a tile controller was implemented and tested with an FPGA, and we are now designing a custom integrated circuit to fulfill this purpose to be radiopure. Finally, to provide low power and radiopure communication, R&D on a silicon photonic-based interface is ongoing with devices currently being characterized. In this contribution, an overview of these key components with their most recent results will be presented. This includes SPAD array characterization, a demonstration of a photodetection module prototype converting a pulse of light into a digital signal, interposer DC and RF characterizations and the silicon photonic communication interface modulation and performances at cryogenic temperature.
MYTHEN III is the latest generation of single photon-counting strip detectors developed by the PSD detector group at the Paul Scherrer Institut. It presents the same geometry as its predecessor MYTHEN II (50 μm pitch, 8 mm long strips, 6.4 cm wide modules), but its performance has been greatly improved, in terms of noise, threshold dispersion, count rate capability and frame rate.
The new readout chip, developed in 110nm UMC technology, contains 128 readout channels. Every channel features a double polarity preamplifier and shaper with variable gain and shaping time. Three discriminators, each one having a dedicated threshold, trim bit set and gate signal, process independently the shaped signal. The outputs of the three discriminators feed a counting logic that, according to the selected mode of operation, generates the increment signals for the three following 24-bit counters.
The various chip modes of operation allow use in new applications: the three fully independent counters per strip enable energy binning, time resolved pump-probe applications, but can also push the count rate capability to above 20 MHz per strip with 90% efficiency, thanks to the possibility of counting piled-up photons. Additionally, we implemented an innovative digital communication logic between channels, allowing charge sharing suppression and improving the spatial resolution beyond the strip pitch, as a first demonstration of on-chip interpolation in a single photon-counting detector.
A full MYTHEN III detector has been commissioned, consisting of 48 modules with 10 chip each, covering 120°, which recently started user operation at the powder diffraction end station of the Swiss Light Source.
We will present the architecture of the new detector, starting from the readout chip, and its latest characterization results, showing its superior performance with respect to MYTHEN II. Particular emphasis will be given to the many unpublished results of the novel modes of operation.
Collider experiments as the upcoming Phase II- LHC or the future circular collider (FCC) will increase the demands of the detectors used for tracking. In the FCC, sensors will not only face fluences of up to $1\times10^{17}~n_\mathrm{eq}/\mathrm{cm}^2$ , but also high pile-up scenarios. Therefore, sensors will be required that not only have a good spatial resolution and a very high radiation hardness, but also an excellent time resolution of 5ps. Currently, Low Gain Avalanche Diodes (LGADs), which have an additional gain layer to achieve fast signals through charge multiplication, are the prime candidate when it comes to timing, reaching a resolution of below 30 ps. However, their radiation hardness is not sufficient for future colliders. As an alternative, 3D sensors are an interesting research area, as they are known to be extremely radiation hard. In 3D sensors, there are columns etched into the sensor from the top (junction columns) and from the back (ohmic columns), causing short drift distances, low depletion voltages and a high electric field and, therefore, fast signals.
In this study, the time resolution of both LGADs and 3D sensors was investigated with MIP-like signals generated by a beta-source, as well as measurements using a laser with an infrared wavelength. We will demonstrate that 3D sensors can achieve time resolutions competitive with LGADs.
Transient current technique (TCT) timing measurements allow a position-resolved study of the time resolution. This is interesting especially for the 3D sensors, where the time walk component due to the more complex electric field structure influences the time resolution strongly. We will show that this can be observed in the position dependent time resolution measurements. Additionally, the timing performance of 3D sensors before and after irradiation with reactor neutrons will be demonstrated.
The ATLAS experiment is currently preparing for the High Luminosity Upgrade of the LHC.
An all-silicon Inner Tracker (ITk) that will replace the current ATLAS Inner Detector, is under development with a pixel detector surrounded by a strip detector. The strip system consists of 4 barrel layers and 6 EC disks. After completion of final design reviews in key areas, such as Sensors, Modules, Front-End electronics and ASICs, and a successful large scale prototyping program, the ITk Strip system has started the pre-production phase. We present an overview of the Strip System, and highlight the final design choices of sensors, module designs and ASICs. We will summarise results achieved during prototyping and the current status of pre-production on various detector components, with an emphasis on QA and QC procedures, and preparation for the production phase.
The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about $5-7.5\times10^{34}$cm$^{-2}$s$^{-1}$, to possibly reach an integrated luminosity of $3000-4500\;$fb$^{-1}$ by the end of 2039. This High Luminosity LHC scenario, HL-LHC, will require an upgrade program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker, already running beyond design specifications, and CMS Phase-1 Pixel Detector will not be able to survive HL-LHC radiation conditions and CMS will need completely new devices, in order to fully exploit the highly demanding conditions and the delivered luminosity.
The Phase-2 Outer Tracker (OT) is designed in order to ensure at least the same performances of the Phase-1, in terms of tracking and vertexing capabilities, at the high pileup (100-200 collisions per bunch crossing) expected at HL-LHC. The Phase-2 OT will have higher radition tollerance, granularity and track separation power with respect to the Phase-1. Moreover the Phase-2 OT will have also trigger capabilities since tracking information will be used at L1 trigger stage. In order to achieve such capabilities Phase-2 OT should be able to perform a data reduction directly on front end electronics. This has been implemented through the $p_{T}$ discriminating module concept, each OT module will be composed by two silicon sensors, with a small spacing, read out by a single ASIC which correlates data from both sensors selecting tracker "stubs". These stubs will then be used to perform the tracking for L1 trigger.
This report is focusing on the replacement of the CMS Outer Tracker system, describing new layout and technological choices together with some highlights of research and development activities.
The ALICE collaboration is pursuing the development of a novel and
considerably improved vertexing detector called ITS3, to replace the
three innermost layers of the Inner Tracker System during the LHC Long
Shutdown 3.
The primary goals are to reduce the material budget to the
unprecedented value of 0.05% X_{0} per layer, and to place the first layer
at a radial distance of 18 mm from the interaction point. These
features will boost the impact parameter resolution by a factor two
over all momenta and drastically enhance the tracking efficiency at
low transverse momentum.
The new detector will consist of true cylindrical layers. Each
half-cylinder is based on curved wafer-scale monolithic pixel
sensors. The bending radii are 18, 24 and 30 mm, and the length of the
sensors in the beam direction is 27 mm.
The sensors will be produced using a commercial 65 nm CMOS Imaging
technology and a recent technique called stitching. This allows to
manufacture chips reaching the dimensions of 27 cm x 9 cm on silicon
wafers of 300 mm diameter. The chips will be thinned down to 50 um or
below.
The ITS3 concept foresees cooling by air flow, ultra-light carbon foam
support elements and no flexible printed circuits in the active area.
This demands a power density limit of 20 mW/cm^{2} for the sensor,
and the need to distribute supply and transfer data over the entire
sensors towards circuits located at the short edges of the chip.
This contribution will summarise the status of the microelectronic
developments and present selected results from the characterisation of
the first prototype chips.
Furthermore, it will describe the ongoing efforts on the design of a
first wafer-scale stitched sensor prototype, the MOSS (Monolithic
Stitched Sensor) chip.
Major advances in silicon pixel detectors, with outstanding timing performance, have recently attracted significant attention in the community. In this work we present and discuss the use of state-of-the-art Geiger-mode APDs, also known as single-photon avalanche diodes (SPADs), for the detection of minimum ionizing particles (MIPs) with best-in-class timing resolution. The SPADs were implemented in standard CMOS technology and integrated with on-chip quenching and recharge circuitry. Two devices in coincidence allowed to measure the time-of-flight of 180 GeV/c momentum pions with a coincidence time resolution of 22 ps FWHM (9.5 ps Gaussian sigma). This result paves the path for new generation of cheap plug-and-play trackers with extremely high spatial and timing resolution, meant to be used in beam test facilities.
Depleted Monolithic Active Pixel Sensors are of highest interest at the HL-LHC and beyond for the replacement of the Pixel trackers in the innermost radii of HEP experiments where maximum performance, and cost effectiveness is required. They aim to provide high granularity and low material budget over large surfaces and ease of integration. This research includes the development of radiation hard DMAPS with small collection electrode in TowerJazz 180 nm CMOS imaging technology with asynchronous read-out (MALTA sensor), design and fabrication of prototypes, and characterization under high demanding conditions. The MALTA sensor features a pixel pitch of 36um and has been optimised for radiation hardness and best possible time resolution. The presentation will summarise the latest measurement results for sensor design and process optimisation towards radiation hardness of >2x10^15 n_eq/cm^2 (NIEL) and 100Mrad (TID). Spatial emphasis will be given to the optimisation of its time-resolution of 2ns in order to utilise the sensor for demanding time-tagging applications in a fine-pitch pixel tracker.
Both the current upgrades to accelerator-based HEP detectors (e.g. ATLAS, CMS) and also future projects (e.g. CEPC, FCC) feature large-area silicon-based tracking detectors. Using production lines of industrial CMOS foundries to fabricate silicon radiation detectors, both for pixels and for large-area strip sensors would be most beneficial in terms of availability, throughput and cost. In addition, the availability of multi-layer routing of signals will provide the freedom to optimize the sensor geometry and the performance, with biasing structures implemented in poly-silicon layers and MIM-capacitors allowing for AC coupling. First samples of pixel sensors coming from the LFoundry production line have already been tested and showed good performance up to irradiation levels of 10^16 neq.cm^-2 for their potential operations as sensors for the CMS inner tracker. This presentation will focus on the systematic characterization of pixel modules at high irradiation levels, up to 1.64 x 10^16 neq.cm^-2, studying the performance in terms of charge collection, position resolution and hit efficiency with measurements performed in the laboratory and with beam tests.
The unprecedented density of charged particles foreseen at the next generation of experiments at future hadronic machines poses a significant challenge to the tracking detectors, which are expected to withstand extreme levels of radiation as well as to be able to efficiently reconstruct a huge number of tracks and primary vertices. To meet this challenge new extremely radiation hard materials and sensor designs will be needed, to build high granularity and excellent time resolution tracking detectors. In particular, the availability of the time coordinate ("4D-tracking") significantly simplifies the track and vertex reconstruction problem. Diamond 3D pixel sensors, with thin columnar resistive electrodes orthogonal to the surface, specifically optimised for timing applications may provide an optimal solution to the above problems. The 3D geometry enhances the well-known radiation hardness of diamond and allows to exploit its excellent timing properties, possibly improving the performances of the extensively studied planar diamond sensors.
We report on the timing characterization, based on beta-source and particle beam tests, of innovative 3D diamond detectors optimised for timing applications, fabricated by laser graphitisation of conductive electrodes in the bulk of 500μm thick single-crystal diamonds, developed within the INFN TimeSpot initiative.
A time resolution well below 100 ps have been obtained with a prototype 55x55μm^2 pitch sensor at a recent beam test at CERN, with a measured efficiency above 99%.
We have also fabricated ten 32x32, 55x55μm^2 pitch sensors which are being bump-bonded on a dedicated 28nm ASIC and will be tested during this year.
Preliminary results on the simulation of the full chain of signal formation in the sensor will also be presented and plans for further optimisation briefly discussed.
Prospects on the construction and test of a “4D" diamond tracker demonstrator will be finally discussed.
We describe the status of the ATLAS Forward Proton Detectors (AFP and ALFA) for LHC Run 3 after all refurbishments and improvements done during Long Shutdown 2. Based on analysis of Run 2 data, the expected performance of the Tracking and Time-of-Flight Detectors, the electronics, the trigger, and the readout and detector control and data quality monitoring are described. Finally, the physics interest and the most recent studies of beam optics and detector options for participation at the HL-LHC are discussed.
The Inner Tracker (ITk) will be one of the major upgrades that the ATLAS experiment will undergo during the long shutdown 3 of the LHC. The ITk Pixel detector will be composed by an Inner System (IS), two Endcaps (EC) and an Outer Barrel (OB). The OB itself will be composed of more than 4,000 pixel modules, arranged on modular "local support" structures (longerons and half rings).
In total, 158 local support structures will compose the OB. QC testing will be performed at the different stages of production (modules standalone, module loaded on cells and modules integration to loaded local supports, and after integration of several loaded local supports).
Dedicated environmental boxes will be developed for the purpose, providing the required connectivity to services (CO2 cooling, power and data connectivity), light tightness and safe operation area during testing.
In order to ensure the safety of operation of several modules at the loaded local support QC testing and integration stage, a dedicated DCS and Interlock system was developed at CERN, based entirely on industrial PLC solutions and providing a Scada WinCC-OA interface. Such system is meant to be employed in a standalone configuration during QC tests, while at the integration stage it is foreseen to be coupled to the specific interlock crate of the ITk.
The system is meant to be modular and adaptable to the several different test configurations which are foreseen at the QC and integration stage.
The talk will give an overview of the system and its capabilities as well as describe the validation of its operation in a representative use case, with a system test setup currently operating at CERN.
The ATLAS experiment will undergo substantial upgrades to cope with the higher radiation environment and particle hit rates foreseen for HL-LHC. The phase II upgrade will include the replacement of the inner detector with a completely new silicon-based tracker. The ATLAS phase II Inner Tracker (ITk) will consist of hybrid pixel detectors and silicon strip detector layers. The innermost five-barrel layers and several endcap rings will be equipped with hybrid pixel detector modules. The modules are consisting of bare silicon modules connected to flexible printed circuits. Bare silicon modules are made of a silicon pixel sensor connected to either four FE chips to form a quad module or one FE chip to form a single chip module. The ITk phase II pixel community has conducted many developments geared towards meeting the necessary module production quality and throughput. These include establishing quality checking routines of bare module components, tooling developments for their assembly as well as electrical testing infrastructure to assess their operability to specification. A dedicated program to set in motion this effort and streamline these various stages was established using the RD53A front-end chip. Subsequent test and assembly work is being carried out using the ITkPix chips which are final size FE chips. This talk will provide a detailed overview of these developments and their results in preparation for the ATLAS ITk pixel phase II upgrade module production.
The High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) requires new radiation tolerant silicon pixel sensors. In the case of the CMS experiment, the first layer of pixel detectors will be installed at about 3 cm distance from the beam pipe: fluence up to 2E16 neq/cm2 (1 MeV equivalent neutrons) are expected. The 3D concept for silicon pixel sensors presents several advantages with respect to traditional, planar, sensors. Thanks to their peculiar structure, 3D sensors are resistant to radiation damage, making them suitable for use in the inner layer of the future CMS tracker. In this presentation results obtained in beam test experiments with highly irradiated 3D and planar pixel sensors interconnected with the RD53A readout chip are reported. RD53A is the first prototype in 65nm technology issued from RD53 collaboration for the future readout chip to be used in the upgraded pixel detectors. The sensors were made in FBK foundry in Trento, Italy, and their development was done in collaboration with INFN (Istituto Nazionale di Fisica Nucleare, Italy). Both 3D and planar sensors feature a pixel area of 2500 μm2 and an active thickness of 150 μm. The interconnected modules, irradiated to fluences up to 2.4E16 neq/cm2, were tested in various test beam facilities: analysis of collected data shows excellent performances measured after unprecedented irradiation fluences. All results are obtained in the framework of the CMS R&D activities.
The current prototype for the proposed sensor was developed in 180nm TSI HV-technology with a 24x40 pixel matrix. Single pixels exploit deep nwells on p-substrate diodes. Secondary particles are collected on the deep n-wells which include the front-end pixel electronics. Front-end electronics contains an integrator in addition to a comparator. Each time the charge acquired surpasses the threshold of the comparator a pump pulse is generated and counted into an 8-bit register, and the integrator is reset. By storing an 8-bit timestamp of the first and last pump, it is possible to obtain with presition the charge acquired during the integration time. A 16-bit output resolution is achieved by this Pump-timestamp method, which is converted into 2 LWDS lines with 4 bits in parallel, to increase data transfer speed, as well as to maintain the integrity of the output. Preliminary tests shown a noise floor of 0.8 fC with a maximum charge of 3000 fC, limited by the resolution bits. The sensor presents a linear response along the whole dynamic range. A test with a high energy particles beam was carried out, the results show the performance of the sensor under real life conditions, as well as the radiation hardness capabilities of it.
In order to cope with the occupancy and radiation doses expected at the High-Luminosity LHC, the ATLAS experiment will replace its Inner Detector with an all-silicon Inner Tracker (ITk), containing pixel and strip subsystems. The strip detector will be built from modules, consisting of one or two n+-in-p silicon sensors, PCB hybrids accommodating the front-end electronics, and powerboard providing high voltage, low voltage, and monitoring electronics. The aluminium strips of the silicon sensors developed for the ITk project are AC-coupled with n-type implants in a p-type float-zone silicon bulk. The module powering configuration includes a voltage of up to 0.5 V across the sensor coupling capacitor. However, this voltage is usually not applied in the sensor irradiation studies due to the significant technical and logistical complications. To study the effect of an irradiation and a subsequent beneficial annealing on the ITk strip sensors in real experimental conditions, four prototype ATLAS17LS miniature sensors were irradiated by Co60 source and annealed for 80 minutes at 60°C, both with and without the bias voltage of 0.5 V applied across the coupling capacitors. The values of interstrip resistance measured on irradiated samples before and after annealing indicate that increase of radiation damage caused by the applied voltage can be compensated by the presence of this voltage during annealing.
The high luminosity upgrade of the Large Hadron Collider, foreseen for 2028, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker (ITk). The expected total integrated luminosity of 4000 fb^−1 means that the strip part of the ITk detector will be exposed to the total particle fluences and ionizing doses reaching the values of 1.6E15 1 MeV n_eq/cm^2 and 0.66 MGy, respectively, including a safety factor of 1.5. Radiation hard n+-in-p micro-strip sensors were developed by the ATLAS ITk strip collaboration and are produced by Hamamatsu Photonics K.K. The active area of each ITk strip sensor is delimited by the n-implant bias ring, which is connected to each individual n+ implant strip by a polysilicon bias resistor. The total resistance of the polysilicon bias resistor should be within a specified range to keep all the strips at the same potential, prevent the signal discharge through the grounded bias ring and avoid the readout noise increase. While the polysilicon is a ubiquitous semiconductor material, the fluence and temperature dependence of its resistance is not easily predictable, especially for the tracking detector with the operational temperature significantly below the values typical for commercial microelectronics.
Dependence of the resistance of polysilicon bias resistor on the temperature, as well as on the total delivered fluence and ionizing dose, was studied on the specially-designed test structures called ATLAS Testchips, both before and after their irradiation by protons, neutrons, and gammas to the maximal expected fluence and ionizing dose. The resistance has an atypical negative temperature dependence. It is different from silicon, which shows that the grain boundary has a significant contribution to the resistance. We will discuss the contributions by parameterizing the activation energy of the polysilicon resistance as a function of the temperature for unirradiated and irradiated ATLAS Testchips.
The ATLAS experiment is currently preparing for an upgrade of the inner tracking detector for High-Luminosity LHC operation, scheduled to start in 2027. The new detector, known as the Inner Tracker or ITk, employs an all-silicon design with five inner Pixel layers and four outer Strip layers. The staves are the building blocks of the ITk Strip barrel layers. Each stave consists of a low-mass support structure which hosts the common electrical, optical and cooling services as well as 28 silicon modules, 14 on each side. To characterize the stave, a set of electrical and functional measurements have been performed both at room and at cold temperature. In this conference, the results on the first fully instrumented pre-production staves assembled at Brookhaven National Laboratory will be presented
During the era of the High-Luminosity (HL) LHC the experimental devices will be subjected to enhanced radiation levels with fluxes of neutrons and charged hadrons in the outer tracker detectors (200mm - 1200mm from the beam axis) from $3x10^{14}$ to $1x10^{15}$ neq/$cm^{2}$ and total ionization doses from 10 kGy to 750 kGy after 3000 $fb^{-1}$ of irradiation. A systematic program of radiation tests with neutrons and charged hadrons is being run by LHC collaborations in view of the upgrade of the experiment, in order to cope with the higher luminosity of HL-LHC and the associated increase in pile-up events and radiation fluxes. In this work, complementary radiation studies with gamma photons from a 60Co source are presented. The doses are of the orders of tens of kGy. The irradiated test structures contain among others gate-controlled diodes (GCD) and field-effect transistors (FET). Τhe alterations in the current components after irradiation are investigated. The results of IV measurements on these devices are presented as a function of the total absorbed radiation dose following a specific annealing protocol. The measurements are compared with the results of a TCAD simulation. The devices under test are made of oxygen enriched float zone p-type silicon.
The ATLAS collaboration is working on a major upgrade of the Inner-Tracker, able to withstand the extreme operational conditions expected for the forthcoming High-Luminosity Large Hadron Collider (HL-LHC) upgrade. During the prototyping phase of the new large area silicon strip sensors, the community observed a degradation of the breakdown voltage (down to 200-500 V from $\geq$1 kV in bias voltage) when the devices with final technology options were exposed to high humidity, recovering the electrical performance prior to the exposure after a short period in dry conditions [J. Fernandez-Tejero, et al., NIM A 978 (2020) 164406]. These findings helped to understand the humidity sensitivity of the new sensors, defining the optimal working conditions and handling recommendations during production testing.
In 2020, the ATLAS strip sensor community started the pre-production phase, receiving the first sensors fabricated by Hamamatsu Photonics K.K. using the final layout design. The work presented here is focused on the analysis of the humidity sensitivity of production-like sensors with different surface properties, providing new results on their influence on the humidity sensitivity observed during the prototyping phase.
Additionally, the new production strip sensors were exposed to short (days) and long (months) term exposures to high humidity. This study allows to recreate and evaluate the influence of the detector integration environment expected during the Long Shutdown 3 (LS3) in 2025, where the sensors will be exposed to ambient humidity for prolonged times. A subset of the production-like sensors were irradiated up to fluences expected at the end of the HL-LHC lifetime, allowing the study of the evolution of the humidity sensitivity and influence of the passivation layers on sensors exposed to extreme radiation conditions.
A new generation of Monolithic Active Pixel Sensors (MAPS), produced in a 65 nm CMOS imaging process, promises higher densities of on-chip circuits and, for a given pixel size, more sophisticated in-pixel logic compared to larger feature size processes. MAPS are a cost-effective alternative to hybrid pixel sensors since flip-chip bonding is not required. In addition, they allow for significant reductions of the material budget of detector systems, due to the smaller physical thicknesses of the sensor and the absence of a readout chip.
The TANGERINE project aims for a sensor with a spatial resolution below 3 μm, temporal resolution below 10 ns, and a total physical thickness below 50 μm, suitable for future Higgs factories or as beam telescope in beam-test facilities. The sensors will have small collection electrodes (order of μm), to maximize the signal-to-noise ratio and hence minimize power dissipation in the circuitry. An extensive program of electric field and Monte Carlo simulations is pursued, to optimize the sensor layout and to reach full depletion of the epitaxial layer, hence high hit detection efficiencies, despite the small collection electrodes. This includes different types of process modifications to enlarge the depletion region and enhance the lateral electric field strength.
The first batch of test chips, featuring the full front-end amplifiers with Krummenacher feedback, was produced and tested at the Mainzer Mikrotron (MAMI) end of 2021. MAMI provides an electron beam with currents up to 100 μA and an energy of 855 MeV. The analog output signal of the test chips is recorded with a high bandwidth oscilloscope and used to study the charge-sensitive amplifier of the chips in terms of waveform analysis. A beam telescope was used as a reference system, to allow for also track-based analysis of the recorded data.
High luminosity upgrades will be performed on all experiments at CERN’s Large Hadron Collider. The increased number of events will provide a larger statistic, giving a consequent better probability of discovering new phenomena. Not only will this cause an increase in radiation damage to the detector systems, but this will give an increased event overlap. As a result, radiation-tolerant detectors with a fast response time are being researched and developed in several detector development groups. 3D silicon sensors have shown to be one of the most radiation hard silicon sensors technologies. In 3Ds the inter-electrode distance is decoupled from, and can be made much shorter than, the substrate thickness. The proximity of the electrodes to the point of charge carrier formation allows for a fast signal response, reduced trapping probabilities, and suppresses effects caused by radiation damage. The poster will present results on 3D sensor timing properties and discuss them in perspective to luminosity upgrade applications.
A silicon-based modern detector, which acts as an active-target capable of imaging particles in 3D, similar to a bubble chamber, does not exist. Ideas for a silicon active target providing continuous tracking were put forward already almost 40 years ago, but the required technology did not exist until recently.
In this talk, a project to construct the first silicon active target based on silicon pixel sensors, called Pixel Chamber, will be described. The aim is to create a bubble chamber-like high-granularity stack of hundreds of very thin monolithic active pixel sensors glued together, capable of performing continuous, high resolution (O($\mu m$)) 3D tracking, including open charm and beauty particles. For the stack, the ALPIDE sensor, designed for the ALICE experiment at the CERN LHC, will be used.
The power consumption of a stack consisting of hundreds of sensors could result in very high temperatures, affecting the performance of the detector, thus requiring a cooling scheme. Simulations were carried out to evaluate different options and converge on a cooling solution. Preliminary results of laboratory cooling tests will be presented.
High-efficiency tracking and vertexing algorithms were developed to reconstruct tracks and vertices inside Pixel Chamber. They were tested on Monte Carlo simulations of proton-silicon interactions occurring inside the detector. The vertex resolution can be up to one order of magnitude better than state-of-the-art detectors like those of LHC experiments. The tracking algorithm has been also tested with real data, using tracks produced in a single ALPIDE sensor exposed to electrons and hadrons beams with very good results.
Finally, the first results obtained for the development of prototypes of stacks of few ALPIDE sensors will be presented. Future perspectives of the project will be illustrated at the end of the talk.
The MONOLITH ERC Advanced project aims at producing a monolithic silicon pixel ASIC with picosecond-level time stamping by using fast SiGe BiCMOS electronics and a novel sensor concept, the Picosecond Avalanche Detector (PicoAD).
The PicoAD uses a multi-PN junction to engineer the electric field and produce a continuous gain layer deep in the sensor volume. The result is an ultra-fast current signal with low intrinsic jitter in a full fill factor highly granular monolithic detector.
A proof-of-concept ASIC prototype confirms that the PicoAD principle works according to simulations. Testbeam measurements show that the prototype is fully efficient and achieves time resolutions down to 24ps.
Single Photon Avalanche Diodes (SPADs) are getting rising attention in the field of optical sensing systems, since they can offer outstanding time and space resolution in a wide set of applications. In addition, SPADs can take advantage of CMOS planar technology, which enables the integration of both sensor and processing electronics in the same chip.
This work will present the results from the characterization of a SPAD based sensor, fabricated in a 150 nm CMOS technology, for charged particle tracking. In order to compensate for the relatively high dark noise mostly deriving from using a non-custom technology, two chips of SPADs were vertically interconnected by means of bump bonding techniques, to make up a dual layer structure. The detection system is based on the coincidence of signals coming from the two different layers of SPAD sensors. If a particle passes through both the sensing elements of a bi-layer cell, the two pulses overlap with each other and a coincidence signal is generated. On the other hand, obtaining overlapping signals as a consequence of dark pulses is unlikely, due to the statistical nature of noise. Dark count rate (DCR) measurements, performed on both independent single layer and dual layer chips, featured respectively a median value approximately equal to $2\;Hz/\mu m^2$ and $100\;\mu Hz/\mu m^2$, therefore demonstrating the beneficial impact of the two-layer approach on noise performance.
In the conference paper, measurement results relevant to crosstalk featured by single and dual layer chips will be discussed. The structure under test consists of $1728$ cells with a pitch of $50\;\mu m$. Different measurement procedures, described in the final paper, have been used to study the crosstalk contribution coming from pixels highly affecting the noise performance of the neighboring ones. Eventually, some considerations about crosstalk probability will be provided.
In the past few years, thanks to the introduction of controlled low gain and to the optimization of the sensor design, silicon sensors have become the detector of choice for the construction of 4D trackers. Presently, both the ATLAS and CMS experiments are building large timing layers (about 20 m2) to add to their experiment the capabilities of time-tagging charge particles.
In this contribution, I will present the 4DInSiDe project that aims at developing the next generation of 4D silicon detectors characterized by a fully active detecting volume, low material budget and high radiation tolerance.
To this purpose, different areas of research have been identified, involving the development, design, fabrication and test of radiation-hard devices that guarantee to operate efficiently in the future high energy physics experiments. This has been enabled thanks to ad-hoc advanced TCAD modelling of LGAD devices, accounting for both technological issues, e.g. sensitivity of the gain layer, as well as physical aspects such as different avalanche generation models and combined surface and bulk radiation damage effects modelling. A massive test campaign has been carried out on specifically devised LGAD structures, both not irradiated and irradiated ones, fostering the validation of the development framework and the evaluation of the impact of several design options, thus orienting the sensor design and optimization before its large volume production.
This work is focused on reviewing the progress and the relevant detector developments obtained during the research activities in the framework of the Italian 4DInSiDe collaboration.
Monolithic Active Pixel Sensors (MAPS) are a promising technology that provides large sensitive areas at potentially low power consumption and low material budget. The ARCADIA project is developing Fully Depleted MAPS (FD-MAPS) with an innovative sensor design, that uses a backside bias to improve charge collection efficiency and timing over a wide range of operational and environmental conditions. The sensor design is based on a modified 110 nm CMOS process and incorporates a low-doped n-type silicon active volume with a p+ region at the bottom. The p-n junction sits on the bottom of the sensor, which results in the depletion region growing from the backside surface with increasing bias voltage. These FD-MAPS are thus operational at low front-side supply voltages while facilitating a fully depleted silicon bulk, which allows the electrode on the top to read out fast electron signals produced by drift.
The ARCADIA collaboration has produced a large set of prototypes in a first engineering run, with a main design consisting of a 512×512 pixel matrix with 25 $\mu$m pixel pitch and other smaller active sensor arrays. Test structures of pixel matrices with pixel pitches ranging from 10 to 50 $\mu$m and total thicknesses of 50 to 200 $\mu$m have been included, to ease the characterization of the sensors independently from integrated electronics.
We will give an overview of the status of the project including first results of the operation of the main demonstrator chip, and then focus on the characterization of the passive pixel matrices which include Capacitance-Voltage (CV) and Current-Voltage (IV), as well as Transient Current Technique (TCT) measurements with a red and an infrared laser. The results are supported by Technology Computer Aided Design (TCAD) simulations. An additional emphasis will be put on the design of pixels optimized for timing applications with sub-100 ps resolution.
The ALICE collaboration is currently carrying out the final commissioning the upgraded Inner Tracking System (ITS), a new ultralight and high-resolution silicon tracker designed to match the requirements of the experiment in terms of material budget, readout speed and low power consumption of the sensors. The upgraded ITS has an active area of about 10m2, consisting of 24120 Monolithic Active Pixels Sensors (referred to as ALPIDE) produced using the 180 nm TowerJazz CMOS image sensor process. They are assembled in seven concentric layers around the beam pipe ranging from 22 mm to 406 mm. The extremely low material budget of 0.35% X0, the fine granularity with a pixel size of 27um x 29um and the small distance of the innermost layer to the beam axis will allow a major improvement of the detector performance in terms of impact resolution and tracking efficiency in particular for low p_T.
After the end of the production in late 2019, the fully assembled ITS was thoroughly characterised during the on-surface commissioning before being installed in the ALICE experiment in the beginning of 2021. Since then the full ITS detector system has been extensively studied in terms of performance and operational stability both in stand-alone mode including cosmic data taking and integrated with the full ALICE detector system.
In this contribution we present the operational experience gained with the upgraded ITS during commissioning as well as selected results of the LHC pilot beam tests providing first measurements of the detector performance in terms of efficiency and spatial resolution.
Without an external magnetic field, the position resolution of silicon sensors is about $pitch\;size/\sqrt{12}$: in identical conditions, silicon sensors with resistive read-out achieve a resolution of a few percent of the pitch size. This remarkable improvement is due to the introduction of resistive read-out in the silicon sensor design. Resistive silicon sensors are based on the LGAD technology, characterised by a continuous gain layer and by an internal signal-sharing mechanism. Thanks to an innovative electrode design aimed at maximising signal sharing, the second FBK production of RSD sensors, RSD2, achieves a position resolution on the whole pixel surface of about 3 microns for 200-micron pitch, 15 microns for a 450-micron pitch and less than 40 microns for a 1300-micron pitch. RSD2 arrays have been tested in the Laboratory for Innovative Silicon Sensors in Torino using a Transient Current Technique setup equipped with a 16-channels digitizer, allowing simultaneously recording all the detector channels. In this contribution, I will present the characteristics of RSD2 and the results obtained with analytic methods and with machine learning algorithms.
The High Luminosity-Large Hadron Collider is expected to start in
2027 and to provide an integrated luminosity of 3000 fb-1 in ten year,
about a factor 20 more than what was collected so far. This high
statistics will allow to perform precise measurements in the Higgs sector and
improve searches of new physics at the TeV scale.
The luminosity needed is L ~7.5 1034 cm-2 s-1, correspondent to
~200 additional proton-proton pile-up interactions, which can
significantly degrade the reconstruction performances.
To face such harsh environment some sub-detectors of the ATLAS
experiment will be upgraded or completely substituted.
The current Inner Detector will be replaced with a new all-silicon
Inner Tracker (ITk) designed to face the challenging environment
associated with the high number of collisions per bunch crossing.
In this poster an overview of the ITk performance to reconstruct and
identify high-level objects will be shown.
A particular focus will be given to the pile-up jets tagging and the
impact of the spatial density of the number of collisions per bunch
crossing.
The Belle II experiment at the SuperKEKB $e^+e^-$ collider has started developing an upgrade program on the time frame of 2026-2027 to improve the detector performance and robustness against beam-induced backgrounds.
To replace the current Belle II pixel and strip system (VXD), the VTX detector concept has been developed, a fully pixelated system based on thin Depleted Monolithic Active Pixel Sensors organized in 5, or possibly more, barrel layers.
To optimize the VTX design and compare it with the VXD system, a full simulation framework has been developed and integrated with the standard Geant4-based Belle II simulation, allowing direct comparison among different layouts.
This is made possible by the flexibility of the Belle II track reconstruction code, which can be retrained to operate on any detector layout without changing the code itself.
This poster will present the VTX detector concept, the development of the simulation framework, and the simulation results obtained, such as tracking efficiency and vertex resolution on benchmark physics channels (including D mesons from B decays), showing significant improvements with respect to the VXD.
This simulation work forms the basis for further optimization of the VTX design.
The EUDET-style telescopes provide excellent spatial resolution, but timing capabilities are limited by the rolling shutter architecture. The Telepix prototype is developed to significantly improve the time stamping of the telescopes and to provide a fast trigger signal with a selectable region of interest. This will be used to efficiently take data with small sensor prototypes.
Telepix is designed in the TSI 180nm HV-CMOS process and profits from a decade of research for the Mu3e experiment and others. In a test submission, multiple pixel matrices with 29x124 pixels and a pitch of 25umx165um have been submitted, featuring different amplifiers, based on PMOS or NMOS only as well as full CMOS. These are systematically characterised and compared, both for laboratory as well as test beam measurements.
During a test beam campaign, the fast region of interest trigger has been studied extensively and a delay of below 25ns with respect to a trigger scintillator could be determined, alongside with a jitter of less than 5ns, making Telepix a well suited trigger plane. A full column had been used, to also include different transmission line length that might influence the jitter of the trigger signal.
Also the performance of the three amplifiers has been studied in test beam and laboratory measurements: Efficiencies above 99% and time resolutions below 5ns have been observed for fully integrated readout. The threshold range with efficiencies above 99% strongly depends on the amplifier type, as well as the threshold dependence of the time resolution. Finally, the spatial resolution as a function of the detection threshold has been determined.
The EUDET-style beam telescope are introduced, the specifications derived and sensor design introduced. A comparison of the different chips from laboratory measurements and a test beam campaign will be presented and the region of interest triggering capabilities will be demonstrated.
The TRISTAN project is the upgrade of the KATRIN experiment that will search for sterile neutrinos with mass in the keV range through precise measurements of the entire Tritium $\beta$-spectrum.
For this purpose, the current KATRIN detector must be replaced with a multipixel detector based on Silicon Drift Detectors (SDDs). SDDs have a small anode capacitance that is reflected in a small equivalent noise charge and therefore in a very high energy resolution close to the Fano limit in Silicon. Moreover, thanks to this small capacitance, the signal risetimes are of the order of few tens of nanoseconds. These features make SDDs ideal for high-rate spectroscopy. In particular, they are commonly used for X-ray measurements. Electron spectroscopy is a relatively novel application, it is therefore necessary to characterize SDDs response to electrons.
We focused our attention on two aspects: the detector dead-layer and the electron backscattering probability. We performed precise measurements in a dedicated setup consisting in a SDD matrix and an electron-gun as a monochromatic and collimated electrons source. In both cases we compared our results with Geant4 Montecarlo simulations.
The precise knowledge of SDDs response to electrons is mandatory in order to accurately reconstruct the continuous $\beta$-spectrum that will be measured in TRISTAN.
We have also investigated the possibility to use a SDD as a versatile and compact $\beta$ spectrometer that can be operated with standard technologies. The goal is to make precise measurements of some interesting $\beta$-decaying isotopes that can have an impact in neutrino and nuclear physics.
In the last few years, fast timing detectors have become more and more important for high energy physics and for technological applications. The CMS Proton Precision Spectrometer (PPS), operating at the LHC, makes use of 3D silicon tracking stations to measure the kinematics of protons scattered in the very forward region, as well as timing detectors based on planar single crystal CVD diamond to measure the proton time-of-flight with high precision. The time information is used to reconstruct the longitudinal position of the proton interaction vertex and to suppress pile-up background. To move PPS detectors closer to the circulating LHC beams they are housed in special movable vacuum chambers, the Roman Pot, placed in the beam pipe. A novel architecture with two diamond sensors read out in parallel by the same electronic channel had been used to enhance the timing performance of the detector. A dedicated amplification and readout chain had been developed to sustain particle fluency of $\sim$1 MHz/channel. The PPS timing detector has operated demonstrating its capability to reconstruct the interaction vertex and to be used to suppress pile-up background. In Run 2 detectors were exposed to a highly non-uniform irradiation, with local peaks above $10^{16}$neq/cm$^2$, a similar value is expected in the future in Run 3. LHC data and subsequent test beam results show that the observable radiation damage only led to a moderate decrease of the detector timing performance. We will present the PPS timing system in detail. Detector Performance in Run2 will be reported, inclusive of the recent studies of radiation effects. The timing system has been upgraded and new detectors packages are currently being installed, with the goal of reaching an ultimate timing resolution of better than 30 ps on protons in the TeV energy range.
Data quality monitoring (DQM) and data certification (DC) are of vital importance to advanced detectors such as CMS, and are key ingredients in assuring solid results of high-level physics analyses using its data. The current approach for DQM and DC is mainly based on manual monitoring of reference histograms summarizing the status and performance of the detector. This requires a large amount of person power while having a rather coarse time granularity in order to keep the number of histograms to check manageable. We discuss some ideas for automatic DQM and DC using machine learning at the CMS detector, focusing on a number of case studies in the pixel tracker. In particular, using legacy data taken in 2017, we show that data certification using autoencoders is able to accurately spot anomalous detector behaviour, with a time granularity previously inaccessible to the human certification procedure. We propose some ideas and plans to commission these automatic DQM and DC procedures in the coming Run 3 of CMS data taking.
The Quality Control (QC) of pre-production strip sensors for the Inner Tracker (ITk) of the ATLAS Inner Detector upgrade has finished, and the collaboration has embarked on the QC test programme for production sensors. This programme will last more than 3 years and comprises the evaluation of approximately 22000 sensors. 8 Types of sensors, 2 barrel and 6 endcap, will be measured at many different collaborating institutes. The sustained throughput requirement of the combined QC processes is around 500 sensors per month in total. Measurement protocols have been established and acceptance criteria have been defined in accordance with the terms agreed with the supplier. For effective monitoring of test results, common data file formats have been agreed upon across the collaboration. To enable evaluation of test results produced by many different test setups at the various collaboration institutes, common algorithms have been developed to collate, evaluate, plot and upload measurement data. This allows for objective application of pass/fail criteria and compilation of corresponding yield data. These scripts have been used to process the data of more than 2500 sensors so far, and have been instrumental for identification of faulty sensors and monitoring of QC testing progress. The analysis algorithms and criteria were also used in a dedicated study of strip tests on gamma-irradiated full-size sensors.
PIONEER is a next-generation experiment to measure the charged-pion branching ratio to electrons vs muons, Re/μ and pion beta decay (Pib) π+→π0eν. Re/μ provides the best test of e-µ universality and is extremely sensitive to new physics at high mass scales; Pib could provide a clean high precision value for Vud. PIONEER was approved with high priority at the Paul Scherrer institute (PSI), with the plan to start data taking as early as 2028.
PIONEER features a high granularity active target (ATAR), designed to suppress the muon decay background sufficiently so that the eν tail can be directly measured. In addition, the ATAR will provide detailed 4D tracking information to suppress other significant systematic uncertainties, and to separate the energy deposits of the pion decay products in both position and time.
The chosen technology for the ATAR is Low Gain Avalanche Detector (LGAD): thin silicon detectors with moderate internal signal amplification (up to a gain of ~50). LGADs have fast rise time and short full charge collection time, and are capable of providing measurements of minimum-ionizing particles (MiP) with time resolution as good as 17 ps. The ATAR baseline design is 48 planes of 2×2 cm strip LGADs with 120 μm of active thickness. To achieve a ~100% active region, several technologies still under research are being evaluated, such as AC-LGADs and TI-LGADs. As dynamic range from MiP (positron) to several MeV (pion/muon) of deposited charge is expected, the detection and separation of close-by hits in such a wide dynamic range will be a main challenge.
In the contribution, a brief introduction to the PIONEER experiment will be presented, then studies made on ATAR candidate LGAD sensors with TCT laser and particle beam will be shown. Furthermore, results with integrated amplifier chips and interposed flex cable will be presented.
Scientific Charge-Coupled Devices (CCDs) have been widely used in astronomy and particle physics due to their great spatial resolution and sensitivity to low-energy signals. The skipper-CCD, a recently developed sensor, allows to measure single-electron signals with sub-electron noise, making its application very attractive in experiments where a low-energy threshold is required. In this talk I will describe the skipper-CCD technology and discuss its current usage in dark matter and neutrino experiments. Furthermore, I will give an overview of the ongoing efforts for constructing multi-kg experiments with skipper-CCDs.
The proven potential of 3D geometries at higher than $10^{16} n_{eq}/cm^{2}$ radiation fluences, in combination with a small cell approach, makes them an excellent choice for a combined precision timing tracker. In this study, the timing resolution of a single 50 x 50 μm 3D pixel cell is presented in various temperatures through charge collection measurements with discrete electronics in a laboratory setting. The series is complemented by an extensive test-beam campaign with 160 GeV SPS pions, using a multi-plane timing telescope with an integrated pixelated matrix. Through a varied incidence angle study, field uniformity, Landau contribution and collected charge are treated at incidence angles of +/- 12$^{o}$. Using state of the art numerical methods, the choice of instrumentation on signal composition and induced bias on results is also evaluated. Finally, with the help of the EUDAQ telescope, a detailed timing, field and efficiency map is presented with a 5 μm spacial resolution through MIMOSA CMOS tracking at CERN SPS pion beams.
Experiments at the future Electron-Ion Collider (EIC) pose stringent requirements on the tracking system for the measurement of the scattered electron and charged particles produced in the collision, as well as the position of the collision point and any decay vertices of hadrons containing heavy quarks. Monolithic Active Pixel Sensors (MAPS) offer the possibility of high granularity in combination with low power consumption and low mass, making them ideally suited for the inner tracker of the EIC detector(s). In this talk, we will discuss the configuration optimized for the ATHENA detector, selected physics performance metrics, and associated R&D towards a well-integrated, large-acceptance, precision tracking and vertexing solution for the EIC based on a new generation MAPS sensors in 65 nm CMOS imaging technology.
The negative capacitance (NC) feature of doped high-k dielectric HfO2 has emerged with important technological applications in CMOS nanoscale electronic devices. The discovery of ferroelectricity in HfO2 reveals a new perspective for manufacturability and scalability in multiple fields, with groundbreaking implications in the design of low power, steep switching transistors. Ferroelectricity in thin HfO2 films does not degrade with the thickness scaling, showing excellent miniaturization properties. The voltage amplification triggered by the ferroelectric material properties, further pushes its use in almost every low-power application. The NC concept promising to provide room temperature sub-60 mV/decade subthreshold swing in FET devices. The presence of a negative capacitor in the gate stack of a transistor can provide an amplified internal potential (step-up voltage), which can potentially overcome the fundamental limit in the subthreshold swing of conventional transistors. The theory of “capacitance matching” is of utmost importance for obtaining a hysteresis-free operation with maximum amplification of the internal potential.
In this contribution, the INFN-CSN5 NegHEP (NEGative capacitance field effect transistors for the future High Energy Physics applications) project will be presented. The project proposes the use of the NC working principle in the framework of High Energy Physics experiments detection systems at future colliders, fostering the fabrication of tracking devices with high spatial resolution, extremely thin layers and capable of detecting signals from noise in harsh radiation environments. The project intends to study, for the first time ever, the radiation hardness of this innovative technology to irradiation.
Advanced TCAD (Technology Computer Aided Design) modeling will be used aiming at investigating the potentiality of Negative Capacitance (NC) devices in non-conventional application domains (e.g., radiation detection). When numerical simulations are capable of verify experimental results, they will also gain predictive power, resulting in reduced time and cost in detector design and testing.
The Belle II experiment is taking data at the asymmetric Super-KEKB collider, which operates at the Y(4S) resonance. The vertex detector is composed of an inner two-layer pixel detector (PXD) and an outer four-layer double-sided strip detector (SVD). The SVD-standalone tracking allows the reconstruction and identification, through dE/dx, of low transverse momentum tracks. The SVD information is also crucial to extrapolate the tracks to the PXD layers, for efficient online PXD-data reduction.
A deep knowledge of the system has been gained since the start of operations in 2019 by assessing the high-quality and stable reconstruction performance of the detector. Very high hit efficiency, and large signal-to-noise are monitored via online data-quality plots. The good cluster-position resolution is estimated using the unbiased residual with respect to the track, and it is in reasonable agreement with the expectations.
Currently the SVD average occupancy, in its most exposed part, is still < 0.5%, which is well below the estimated limit for acceptable tracking performance. With higher machine backgrounds expected as the luminosity increases, the excellent hit-time information will be exploited for background rejection, improving the tracking performance. The front-end chip (APV25) is operated in “multi-peak” mode, which reads six samples. To reduce background occupancy, trigger dead-time and data size, a 3/6-mixed acquisition mode based on the timing precision of the trigger has been successfully tested in physics runs.
Finally, the SVD dose is estimated by the correlation of the SVD occupancy with the dose measured by the diamonds of the radiation-monitoring and beam-abort system. First radiation damage effects are measured on the sensor current and strip noise, although they are not affecting the performance.
After the manufacture and delivery of a state-of-the-art detection system for the XRF-XAFS beamline of the synchrotron light source SESAME, a new and improved detection system was realized. This new multichannel modular detection system based on Silicon Drift Detectors consists of 8 monolithic multipixel arrays, each comprising 8 (SDD) cells with a total area of 570 mm$^2$. As the previous one, this 64 channels integrated detection system includes ultra-low noise front-end electronics, dedicated acquisition system, digital filtering, temperature control and stabilization. With respect to the SESAME version, the new instrument implements a collimation system yielding a total collimated sensitive area of 499 mm$^2$. Optimized to work in an energy range of 3-30 keV, the system shows an overall energy resolution (sum of its 64 cells) below 170 eV FWHM at the Mn 5.9 Ka line at room temperature. We highlight the system performance, and in particular the peak to background ratio, before and after the collimation of the sensors.
Owing to its excellent radiation hardness, diamond has been widely used as solid-state particle detectors and dosimeters in high-radiation environments. A system based on single-crystal synthetic-diamond detectors has been developed and installed in order to monitor the radiation level and detect beam losses near the interaction region of the SuperKEKB collider for the the Belle II experiment.
In order to assess the crystal quality and response of these devices, all diamond sensors are characterized with different radiation sources, comparing the measurement results with dedicated simulations. We devised a novel current-to-dose-rate calibration method for steady irradiation, which employs a silicon diode as a reference in order to greatly reduce uncertainties associated with the radiation source. The calibration results, in agreement between and X radiation, span a dose rate range from tens of nrad/s to rad/s.
In addition, beam tests of the devices are being carried out at the linac of the FERMI@Elettra FEL in Trieste (Italy), with short 1GeV electron bunches of 1ps duration and bunch charge from one to hundreds of . The aim is to test the transient response to very high intensity pulses and study possible saturation effects due to a very high charge carrier density in the diamond bulk.
A two-step numerical simulation approach is employed to study the time response of the diamond sensor, separating the effects of charge carriers drifting in the diamond bulk from the effects of the circuit on the signal shape.
Validation of the approach is conducted by comparing the simulation with measurements of the TCT (Transient Current Technique) signals generated by particles.
Preliminary results show remarkable agreement between measurements and numerical simulation, where the diamond resistance is modeled as a function of the variable charge density in the diamond bulk.
LHCb physics achievements to date include the world's most precise measurements of the CKM phase 𝛾 and the rare decay $𝐵^0_𝑠$→𝜇$^+$𝜇$^−$, the discovery of 𝐶𝑃 violation in charm, and intriguing hints of lepton-university violation. These accomplishments have been possible thanks to the enormous data samples collected and the high performance of the sub detectors, in particular the silicon vertex detector (VELO). The experiment is being upgraded to run at higher luminosity, which requires 40 MHz readout for the entire detector and newer technologies for most of the sub detectors. The VELO upgrade modules are composed of hybrid pixel detectors and electronics circuits mounted onto a cooling substrate, which is composed of thin silicon plates with embedded micro-channels that allow the circulation of liquid CO$_2$. This cooling substrate gives excellent thermal efficiency, no mismatch to the front-end electronics, and optimises physics performance due to the low and very uniform material distribution. The detectors are located in vacuum, separated from the beam by a thin Al foil. The foil was manufactured through a novel milling process and thinned further by chemical etching. The detectors are linked to the opto-and-power board (OPB) by 60 cm electrical data tapes running at 5 Gb/s. The tapes are vacuum compatible and radiation hard and flexible enough to allow the VELO to retract during LHC beam injection. The upgraded VELO is composed of 52 modules placed along the beam axis divided into two retractable halves. The modules are currently being assembled into the two halves before final installation into LHCb. The design, production, installation and commissioning of the VELO upgrade system will be presented together with test results.
The High Luminosity upgrade of the Large Hadron Collider will force the experiments to cope with harsh radiation environments. The CMS experiment is considering the option of installing 3D pixel sensors in the innermost layer of its tracking system where a fluence up to 2e16 neq/cm2 is expected. This pixel technology should maintain high detection efficiency and manageable power dissipation at such unprecedented expected fluences. Results from beam test experiments with pixelated 3D sensors fabricated at IMB-CNM and bump-bonded to RD53A readout chips are presented. The irradiation with protons of 400MeV-momentum to fluences of roughly 1.3-2.0e16 neq/cm2, as well as the measurement of these sensors in a test beam have been both performed at Fermilab.
The FOOT (FragmentatiOn On Target) experiment aims to measure the double differential cross-sections that are in the energy range of therapeutic interest (100-400 MeV), to produce sufficiently precise measurements. These data will allow a better modelling of the dose imparted to the health tissues traversed, and therefore an accurate assessment of the damage induced during therapy. To succeed the experiment will use a magnetic spectrometer operated in the inverse kinematics mode, i.e. sending ions of the appropriate energy onto a proton rich target, and studying the charge, energy and emission angle of the fragments.
The Microstrip Silicon Detector apparatus is the last tracking station of the magnetic spectrometer, located downstream of the magnets and it consists of 6 layers of silicon microstrip sensors, organised in three x-y stations with mutually orthogonal sensors. The MSD is used to measure the spatial points of the track needed for fragments' momentum reconstruction while providing also additional information about the charge and the energy loss of the charged fragments.
To characterise both its tracking capabilities (namely, its spatial resolution and detection efficiency) and its response to particles that are not
at the ionizing minimum a series of tests at several accelerators have been performed.
We present the results of the complete Microstrip Silicon Detector apparatus, during the construction and testing performed in the laboratory phase, as well as the ones obtained from data taken at beam facilities delivering protons and heavier ions (Carbon and Oxygen).
The High Luminosity Large Hadron Collider (HL-LHC) at CERN is expected to collide protons at a centre-of-mass energy of 14 TeV and to reach the unprecedented peak instantaneous luminosity of $5-7.5\times10^{34} cm^{-2}s^{-1}$ with an average number of pileup events of 140-200. This will allow the CMS experiment to collect integrated luminosities up to 3000-4000 fb$^{-1}$ during the project lifetime. The current CMS Pixel Detector will not be able to survive the HL-LHC radiation conditions and thus CMS will need completely new Inner Tracker in order to fully exploit the highly demanding conditions and the delivered luminosity. The new pixel detector will feature increased radiation hardness, higher granularity and capability to handle higher data rate and longer trigger latency. The design choices for the Inner Tracker Phase-2 upgrade are discussed along with some highlights on the technological approaches and R&D activities.
In the last few years, Low Gain Avalanche diodes (LGAD) have been considered one of the most promising solutions for timing application in HEP experiments, as well as for 4-dimensional tracking, due to some important advantages: larger internal signal, better time resolution and higher radiation hardness with respect to standard p-i-n based sensors.
Although the LGAD technology recently reached a good technology readiness level, an increasing number of foundries and R&D laboratories are proposing novel design schemes and microfabrication technologies mainly focused on improving two key aspects of the technology: i) increasing the radiation hardness at fluence higher than 3e15 neq/cm$^2$ and ii) improve the spatial resolution moving through fine-pixellated and high-fill-factor sensor designs.
In this contribution, the major technology developments in these directions done at Fondazione Bruno Kessler together with INFN Torino will be presented and discussed, supported by experimental results and simulation studies.
To improve the spatial resolution, a novel segmentation scheme named Trench-Isolated LGAD (TI-LGAD) has been developed. In this technology, the pixel segmentation is obtained by means of trenches, physically etched in the silicon, and filled with silicon oxide. The electrical and functional characterization of the first prototypes before and after irradiation will be presented, prooving the possibility to produce LGAD sensors with a pixel pitch of 50 $\mu$m and not-sensitive inter-pixel width less than 5 $\mu$m.
Moreover, to improve the radiation hardness at high fluences, novel junction schemes based on dopant co-implantation with electrical inactive elements (like carbon) and compensated doping profiles are under investigations. The outcome from a simulation campaign and the first experimental results will be presented, showing the potentiality of these techniques to mitigate the effect of the radiation damage on some important figure-of-merit of the sensor, like gain and breakdown voltage.
The MALTA pixel chip is a 2 cm x 2 cm large monolithic sensor developed in the 180 nm TowerJazz imaging process. The chip contains four CMOS transceiver blocks at its sides which allow chip-to-chip data transfer. The power pads are located mainly the side edges on the chip which allows for chip-to-chip power transmission. The MALTA chip has been used to study module assembly techniques using different interconnection techniques to transmit data and power from chip to chip and to minimise the overall material budget. Several 2-chip and 4-chip modules have been assembled using standard wire bonding, ACF and laser reflow interconnection techniques. This presentation will summarise the experience with the different interconnection techniques and performance tests of MALTA modules with 2 and 4 chips tested in a cosmic muon telescope. It will also show first results on the effect of serial power tests on chip performance as well as the impact of the different interconnection techniques and the results of mechanical tests. Finally, a conceptual study for a flex based ultra-light weight monolithic pixel module based on the MALTA chip with minimum interconnections is presented.
The upgrade of the MEG experiment, MEGII, has started physics data taking
in fall 2021, collecting ~ 8x10^13 mu on target during 34 days of DAQ live
time, searching for the Standard Model violating Lepton Flavor Violating
Decay mu->e gamma with sensitivity improved by an order of magnitude.
During this period the pixelated Timing Counter (pTC), a time of flight
detector devoted to extrapolating the muon decay time on target by
measuring the positron hit time, has been fully readout and has
operated stably.
The detector consists of 512 fast plastic scintillator pixels
(120x50(40)x5 mm^3) readout by two arrays of 6 SiPM each connected in series
glued on opposite sides.
Its goal is to achieve a resolution on positron hit time of about 40 ps by
exploiting multiple-hits events.
This contribution will show how the detector achieved the design performance
during the 2021 run reaching ~39 ps for events with 8 hits corresponding to the average number of hits expected from MC simulation for mu->e gamma events.
This result was obtained in spite of a suboptimal performance of electronic
noise and of a slow degradation in dark current due to irradiation damage
on SiPMs.
Instrumental in achieving this performance was a full set of hardware and
software calibration tools developed to align precisely in time and space
the counters relative to each other and to the rest of the MEG II detector.
For the HL-LHC upgrade the current ATLAS Inner Detector is replaced by an all-silicon system. The Pixel Detector will consist of 5 barrel layers and a number of rings, resulting in about 14 m2 of instrumented area. Due to the huge non-ionizing fluence (1e16 neq/cm2) and ionizing dose (5 MGy), the two innermost layers, instrumented with 3D pixel sensors (L0) and 100μm thin planar sensors (L1) will be replaced after about 5 years of operation. All hybrid detector modules will be read out by novel ASICs, implemented in 65nm CMOS technology, with a bandwidth of up to 5 Gb/s. Data will be transmitted optically to the off-detector readout system. To save material in the servicing cables, serial powering is employed for low voltage.
Large scale prototyping programs are being carried out by all sub-systems.
The talk will give an overview of the layout and current status of the development of the ITk Pixel Detector.
For the upgrade of the Large Hadron Collider (LHC) to the High-Luminosity Large Hadron Collider (HL-LHC) the ATLAS detector will install a new Inner Tracker (ITk), which consists completely of silicon detectors. Although different technologies were chosen for the inner and outer part, the major risk for all silicon detectors are heat-ups, which can cause irreparable damages. As, once the detector is installed, detector elements are not accessible for several years or even for the lifetime of the detector, such damages must be avoided by all means.
The ITk interlock system is a hardwired safety system, it acts as last line of defense and is designed to protect the sensitive detector elements against upcoming risks. Core of the interlock system is an FPGA, which houses an interlock matrix. It collects signals from interlock protected devices and distributed signals onto interlock controlled units (e.g. power supplies). Additionally, signals from external systems can be integrated. To keep the number of detector elements, which are out of operation, at a minimum, the power supplies are controlled with a high granularity. The resulting large number of channels also explains why no commercial solution was selected.
We explain the concept in detail, report about the realization of the interlock system and future plans.
Within the RD50 Collaboration, a large and dedicated R&D program has been underway for more than two decades across experimental boundaries to develop silicon sensors with high radiation tolerance for Phase-II LHC trackers. Based on the success of this R&D, these trackers are now entering their construction phase. RD50 is continuing its mission to study silicon sensors for particle tracking, shifting the focus to applications beyond the LHC. The next generation of collision experiments, such as the FCC, requires unprecedented radiation hardness in the range of a few 10$^{17}N_{eq}$ as well as time resolutions of the order of 10ps. Another key challenge is to move the sensor technology away from traditional planar passive float-zone sensors, which form large parts of the current trackers to sensor technologies such as CMOS where front-end electronics can be integrated, and where a wide availability in industry promises cost advantages.
Key areas of recent RD50 research include technologies such as Low Gain Avalanche Diodes (LGADs), where a dedicated multiplication layer to create a high field region is built into the sensor, resulting in time resolutions of a few tens of ps. We also study 3D sensors as a radiation-hard alternative to LGADs for fast timing applications. In another R&D-line we seek for a deeper understanding of the connection between macroscopic sensor properties such as radiation-induced increase of leakage current, doping concentration and trapping, and the microscopic properties at the defect level. A new measurement tool available within RD50 are the Two-Photon-Absorption (TPA) TCT systems, which allow position-resolved measurements down to a few um.
We will summarise the current state-of-art in silicon detector development in terms of radiation hardness and fast timing, and give an outlook on silicon sensors options for e.g. the FCC.
Low Gain Avalanche Detectors (LGADs) are thin silicon detectors with moderate internal signal amplification, providing time resolution as good as 17 ps for minimum ionizing particles. In addition, their fast rise time and short full charge collection time (as low as 1 ns) is suitable for high repetition rate measurements in photon science and other fields. However, a major limiting factor for spatial resolution are electric field termination structures, which currently limit the granularity of LGAD sensors to the mm scale.
AC-LGADs, also referred to as resistive silicon detectors, are a recent variety of LGADs based on a sensor design where the multiplication and n+ layers are continuous, and only the metal layer is patterned. This simplifies sensor fabrication and reduces the dead area on the detector, improving the hit efficiency while retaining the excellent fast timing capabilities of LGAD technology. In AC-LGADs, the signal is capacitively coupled from the continuous, resistive n+ layer over a dielectric to the metal electrodes. A high spatial precision on the few 10‘s of micrometer scale is achieved by using the information from multiple pads, exploiting the intrinsic charge sharing capabilities provided by the common n+ layer. The response depends on the location, the pitch and size of the pads.
Using focused IR-laser scans, the following detector parameters have been investigated with the scope of optimizing the sensor design: sheet resistance and termination resistance of the n-layer, thickness of the isolation dielectric, and pitch and size of the readout pads. Furthermore, capacitance-voltage characterization of the sensors will be shown. Finally, charge sharing distributions produced with data taken at the Fermilab test beam facility will be presented. The results will be used to recommend a base-line sensor for near-future large-scale detector application like the Electron-Ion Collider, where simultaneous precision timing and position resolution is required.
Future collider experiments operating at very high instantaneous luminosity will greatly benefit in using detectors with excellent time resolution to facilitate event reconstruction. For the LHCb Upgrade2, when the experiment will operate at 1.5x10^34/cm/s, 2000 tracks from 40 pp interactions will cross the vertex detector (VELO) at each bunch crossing. To properly reconstruct primary vertices and b-hadron decay vertices VELO hit time stamping with 50ps accuracy is required. To achieve this, several technologies are under study and one of the most promising today is the 3D trench silicon pixel, developed by the INFN TimeSPOT collaboration. These 55µmx55µm pixels are built on a 150µm-thick silicon and consist of a 40µm-long planar junction located between two continuous bias junctions, providing charge-carriers drift paths of about 20µm and signals’ total durations close to 300ps. Two sensors’ batches were produced by FBK in 2019 and 2021. The most recent sensors’ beam test was performed at SPS/H8 in 2021. Various test structures were readout by means of low-noise custom electronics boards featuring a two-stage transimpedance amplifier, and the output signals were acquired with an 8GHz 20GS/s oscilloscope. The arrival time of each particle was measured with an accuracy of about 7ps using two 5.5mm-thick quartz window MCP-PMTs. Two 3D trench silicon pixel test structures and the two MCP-PMTs were aligned on the beam line and acquired in coincidence. Signal waveforms were analyzed offline with software algorithms and pixel signal amplitudes, particle time of arrival and efficiencies were measured. A preliminary analysis indicates efficiencies close to 100% for particles impinging at more than 10 degrees with respect to normal incidence, and time resolutions close to 10ps. More up-to-date results will be presented at the Conference. 3D trench-type silicon pixels appear to be a promising technology for future vertex detectors operating at very high instantaneous luminosity.
The success of the Belle II experiment in Japan relies on the very high instantaneous luminosity, close to 6x10^35 cm^-2 s^-1, expected from the SuperKEKB collider. The corresponding beam conditions generate large rates of background particles and creates stringent constraints on the vertex detector, adding to the physics requirements.
Current prospects for the occupancy rates in the present vertex detector (VXD) at full luminosity fall close to the acceptable limits and bear large uncertainties.
In this context, the Belle II collaboration is considering the possibility to install an upgraded VXD system around 2026 to provide a sufficient safety factor with respect to the expected background rate and possibly enhance tracking and vertexing performance.
Our international consortium has started the design of a fully pixelated VXD, dubbed VTX, based on a depleted CMOS Monolithic Active Pixel Sensor prototype developed for LHC-type conditions and recent light detection layer concepts.
The striking technical features of the VTX proposal are the usage of the same sensor over the few layers of the system and the decrease of the overall material budget below 2 % of radiation length. The new dedicated OBELIX sensor is under development, starting from the existing TJ-MONOPIX-2 sensor. The time-stamping precision below 100 ns will allow all VTX layers to take part in the track finding strategy contrary to the current situation. The first detection layers are designed according a self-supported all-silicon concept, where 4 contiguous sensors are diced out of a wafer, thinned and interconnected with post-processed redistribution layers. Beyond a radius of 3 cm, detection layers follow a more conventional approach with a carbon fiber support structure and long but light flex cables interconnecting sensors.
This talk will review the context, technical details and development status of the proposed VTX as well as discussing performance expectations from simulations.
LHCb has recently submitted a physics case for an Upgrade II detector to begin operation in 2031. The upcoming upgrade is designed to run at instantaneous luminosities of $1.5\times 10 ^{34}cm^{−2} s^{−1}$, to accumulate a sample of more than 300 fb$^{−1}$. The LHCb physics programme relies on an efficient and precise vertex detector (VELO). Compared to Upgrade I, the data output rates, radiation levels and occupancies will be about ten times higher during LHC runs 5 and 6. To cope with the pile-up increase, new techniques to assign b hadrons to their origin primary vertex, and to perform the real time pattern recognition are needed. To solve these problems, a new 4D hybrid pixel detector with enhanced rate and timing capabilities in the ASIC and sensor will be developed. This presentation will discuss the most promising technologies to be used in the future upgrade for the HL-LHC, with emphasis on the timing precision as a tool for vertexing in the next generation detectors. An initial simulation effort has been made to investigate what would be the required temporal resolution sufficient to mitigate pile-up and identify secondary vertices, which points to at least 20 ps per track. The most recent results from beam tests motivated by time measurements will be presented together with the R\& D scenarios for the future upgrade. Improvements in the mechanical design of the Upgrade II VELO will also be needed to allow for periodic module replacement. The design will be further optimised to minimise the material before the first measured point on a track and to achieve a fully integrated module design with thinned sensors and ASICs combined with a lightweight cooling solution.
Proton beam therapy (PBT) is a more advanced form of radiotherapy that allows dose to be delivered more precisely, sparing healthy tissue. In recent years there has been increasing interest in a new high dose rate form of radiotherapy called FLASH. In FLASH radiotherapy, extremely high dose rates above 40 Gy/s and delivery times below 100ms have shown exceptional reduction in damage to healthy tissue with similar tumour control to standard radiotherapy. In addition, such short delivery times have the potential to eliminate dose delivery inaccuracy related to patient movement during treatment. Research is currently underway to develop the first clinical systems capable of delivering therapeutic beams at FLASH rates with protons, electrons and photons.
Two key challenges exist in the development of FLASH PBT:
1) The development of accelerator systems fast enough to deliver spot-scanned PBT beams within a suitably short time frame to elicit the FLASH effect;
2) The improvement of diagnostic and Quality Assurance (QA) detectors capable of making dosimetric measurements at FLASH rates.
A background to PBT and the advantages over conventional radiotherapy is presented. A brief history of FLASH radiotherapy is given with a focus on progress in delivering FLASH PBT. The challenges in both accelerator and diagnostics development are outlined. Finally, the UCL QuARC project to develop a FLASH-ready QA detector for fast proton range measurements is described, with experimental results of the first clinical tests of the prototype detector system.
Muons of cosmic origin have a great capability to penetrate through matter. This property is exploited in muon radiography, a technique which allows to highlight
the presence of discontinuities in the subsoil of different possible origins, such as the presence of cavities, tunnels or rock masses. More generally, it provides two-dimensional maps of the mass distribution; if multiple measurements from different points are available, 3D distributions can be obtained. We have developed, in collaboration with TECNO-IN SpA and S.c.a r.l. STRESS, a detector optimized for borehole studies. The cylindrical shape is realized with arc-shaped plastic scintillator bars combined with rectangular section bars, arranged vertically. This geometry allows to maximize the effective surface of the detector and provides a large investigation volume. Currently the first constructed prototype is 1 m high and has a diameter of about 20 cm. It consists of 64 vertical bars for measuring the azimuth angle and 256 arcs for the z-coordinate measurement, considering a cylindrical coordinates system. The scintillation light is read out by 384 Silicon Photomultipliers, directly coupled to the bars. Particular attention has been paid to the transport of photons inside the scintillators, with the use of light guides realized by the bars itself.
The front-end and acquisition electronics, entirely housed inside the detector, are based on the EASIROC chip and are characterized by limited energy consumption (about 30 W for the entire detector).
The detector is enclosed in a waterproof case and is remotely controlled via ethernet. The presentation will describe the detector and the results obtained in a series of measurements carried out in the subsoil of the hill of Mt Echia in Naples, where its ability to reveal some known cavities and to identify possible hypothesized hidden cavities were tested.
Proton therapy offers highly localised dose distribution and better healthy tissue sparing over conventional radiotherapy. Crucial in optimising patient safety is the proton range: this is the largest source of uncertainty in proton therapy and prevents full advantage being taken of the superior dose conformality. In the clinic, daily Quality Assurance (QA) is performed each morning before patient treatment, including verification of the proton range in water (a proxy for human tissue) for specific beam energies. This process however, often compromises between speed and accuracy. Recently, there has been increased interest in FLASH: a high dose rate form of radiotherapy offering even greater healthy tissue sparing. However, standard detectors used in QA become unusable at FLASH dose rates.
The Quality Assurance Range Calorimeter (QuARC) is currently under development at UCL with our industrial partners Cosylab to provide fast, accurate, water-equivalent proton range measurements for daily QA, with the capability to operate at FLASH dose rates. Based on plastic scintillator developed for the SuperNEMO experiment, the detector is a series of optically isolated scintillator sheets that sample the proton energy deposition along its path. Light from each sheet is measured by a series of photodiodes: this light output is proportional to the deposited energy. An analytical depth-light model is used to fit the data and measure the proton range to sub-mm precision.
Two preliminary beam tests at UCLH with proton pencil beams between 70-110 MeV found that the QuARC is able to consistently recover proton ranges with good accuracy, even at low light levels. Fast curve fitting enables stable real-time range reconstruction at 40 Hz, as protons are delivered to the detector. Due to large dynamic range, the detector can be scaled up to FLASH dose rates. Further measurements are required to fully characterise detector performance and light output with FLASH.
OLD
Recent developments on scintillators together with fast digital signal processing, allowed the implementation of techniques that facilitate their use in applications that required excellent Pulse Shape Discrimination and FOM such as the identification of Special Nuclear Material through both combined gammas counting / spectrometry and neutron counting with time stamp correlated information. This work is presenting extensive tests executed with many radionuclides in agreement with ANSI Standards, SNM (Pu, U, HEU, HEPu) and n-alpha neutron sources measurements and the technical solutions implemented for the realization of two nuclear measurement systems dedicated to nuclear safeguards and nuclear security applications.
NEW
Recent developments on scintillators together with fast digital signal processing enables the implementation of innovative techniques for the identification and accountancy techniques of Special Nuclear Material through both combined gammas counting and spectrometry, and neutron counting with time stamp correlated information. Those techniques leverage the combined and excellent Pulse Shape Discrimination and Time-of-Flight measurements that can be recently obtained. This work is presenting extensive tests executed with many radionuclides in agreement with ANSI Standards, SNM (Pu, U, HEU, HEPu) and n-alpha neutron sources measurements and the technical solutions implemented for the realization of two nuclear measurement systems dedicated to nuclear safeguards and nuclear security applications.
In the uRANIA project (μ-RWELL Advanced Neutron Imaging Apparatus) the μ-RWELL technology is applied to neutrons detection, a key point for homeland security. The device is a compact resistive detector, composed of two elements: the micro-RWELL_PCB, incorporating the amplification stage and the readout plane, and the cathode. This latter works as well as main element for thermal neutron detection: a thin 10B layer, sputtered on the metallic surface, allows the neutron capture with the release of heavy charged particles (alpha or Lithium ion) in the detector gas active volume. The sputtering has been made by the ESS Neutron Detector Coatings Section (Linköpping, SE).
Prototypes with 10 x 10 cm2 active area and different cathodic profiles have been realized and tested at the HOTNES facility of the ENEA Frascati. Meshes sputtered with Boron have been moreover introduced in the device active volume and tested at the same facility.
A remarkable efficiency between 5 and 10% has been measured for thermal neutron, with single detector, with two methods: current and counting mode (CREMAT pre-amplifier). This work required an extensive simulation and validation campaign made with GEANT4.
The project pushes also for strong engineering activities to include FEE and the HV supply system in a compact device. The final goal is to produce an optimized design to start the development of large-area and cost-effective neutron detector for the Radioactive Portal Monitor (RPM) and Radioactive Waste Monitor (RWM), exploiting the compactness of the device that allows a stack of different detectors to increase the effeciency.
The Cosmic Ray Cube is a portable tracking device conceived for outreach activities allowing a direct scientific experience for secondary school students. In the context of the PTOLEMY project, the detector was used to measure the differential muon flux inside the bunker of Monte Soratte, a suitable location at about 50 km north of Rome (Italy). Its simple operation was crucial to finalise the measurements, carried out during the COVID-19 lockdown in a site devoid of scientific equipment. The fine scanning of the differential muon rate highlights the details of the mountain above the bunker providing a map of the thickness of the rock which surrounds the detector. The result shows a muon flux at the Soratte hypogeum of about two orders of magnitude lower than the one observed on the surface.
A 32$\times$32 Bicron 1 mm$^2$ polystyrene scintillating fibre-based beam hodoscope, with an entrance window of 6$\times$6 cm$^2$, has been designed and characterised for monitoring low-energy charged particle beams. The hodoscope has been designed to fit into the 60 Mev/c negative muon beam at Port 1 of the RIKEN-RAL muon facility (UK) as a beam monitor for the FAMU experiment. Each fibre is read by a 1 mm$^2$ Hamamatsu SiPM biased with around $-$70 V, and the signal is fanned out and digitised by means of CAEN VME digitisers.
After calibrations made using cosmic muons and a $^{90}$Sr/$^{90}$Y 3.7 kBq source, the detector has been exposed to the calibrated single-proton beam at CNAO (Italy), in the momentum range between 340 MeV/c and 690 MeV/c. The activation of the instrument materials has been tested by exposing a mock-up to the same particle beam in advance with respect to the measurement run.
This experimental campaign provides further calibration in dE/dx and shows the feasibility of the detector as an instrument for proton beam characterisation too. In particular, aside from its usage in FAMU, we investigated the possibility of using our hodoscope as a beam monitor in hadron therapy at CNAO.
The actual and next decade will be characterized by an exponential increase in the exploration of the Beyond Low Earth Orbit space(BLEO). Moreover, the firsts tentative to create structures that will enable a permanent human presence in the BLEO are forecast. In this context, a detailed space radiation field characterization will be crucial to optimize radioprotection strategies (e.g., spaceship and lunar space stations shielding), to assess the risk of the health hazard related to human space exploration, and to reduce the damages potentially induced to astronauts from galactic cosmic radiation. In this context, since the beginning of the century, many astroparticle experiments aimed at investigating the unknown universe components (i.e., dark matter, antimatter, dark energy) have collected enormous amounts of data regarding the cosmic rays (CR) components of the radiation in space.
Such experiments are cosmic ray observatories. The collected data (cosmic ray events) cover a significant period and permit to have integrated information of CR fluxes and their variations on time daily. Further, the energy range is exciting since the detectors operate using instruments that allow measuring CR in a very high energy range, usually starting from the MeV scale up to the TeV, not usually covered by other space radiometric instruments. Last is the possibility of acquiring knowledge in the full range of the CR components and their radiation quality
The collected data contains valuable information that can enhance the space radiation field characterization.
In this talk, the status of the art in this research topic will be presented and the research topic initiative titled "Astroparticle Experiments to Improve the Biological Risk Assessment of Exposure to Ionizing Radiation in the Exploratory Space Missions" will be presented.
We launched it in December 2021 on three different Frontiers Journals (Astronomy and Space Science/Astrobiology, Public Health/Radiation and Health, Physics/Detectors, and Imaging).
Several hereditary disesases due to retina degeneration affect
one over ~4000 persons resulting in total or partial blindness.
These disesases cannot be cured and the only chance of improving
the quality of life in the patients is a visual prostheses replacing
the damaged layers in the retina.
Some prostheses prototypes already exist and have been implanted.
Nevetherless the improvements in visual acuity is stillbvery limited.
SPEye proposes a novel approach based on a subretinal
implant of a matrix of silicon photodetector with inner amplification
SiPM (Silicon PhotoMultiplier).
The advantage over solutions employing traditional silicon diodes is
that the large inner amplification avoids the need of preamplifier
reducing power consumption to much lower level.
That makes also possible to reduce the size of the single photodiode
down to the size of the cones and rods increasing visual acuity without
increasing power consumption.
A number of preliminary tests have been performed on commercial SiPMs
including electric field calculations, simulation of cell response to
electrical stimuli, detailed measurement of SiPM response to focalized
light response, biocompatibility of the material involved, mechanical
matching to a spherical surface designing and test of a remote power
system, cell deposition on SiPM surface.
Those results are presented together with ideas on how to proceed in
designing optimized custom photodetector for surgical implantation in
animal and humans.
This contribution deals with the development, production and test, within the ANET project, of a new concept of compact neutron collimator, for neutron radiography and tomography. The novel multi-channel collimator, thanks to extensive experimental campaigns, has proved to deliver highly collimated neutron beams within very limited distances, outperforming other types of neutron collimators. This new instrument has been tested in different facilities demonstrating its applicability both on reactor and accelerator based sources. The performances of the ANET collimator and its first application to tomography is shown and discussed.
The positron emission tomography (PET) is an effective functional imaging technique especially for cancer diagnosis. Its performance is strictly connected to the ability to detect and reconstruct photons emitted by the positron - electron annihilation. Its sensitivity is enhanced when time information are included (time-of-flight (ToF) PET). The measure of the detection time difference between the two photons leads to a higher contrast image and more accurate diagnoses.
We describe the studies for a possible development of a ToF-PET based on Micro Pattern Gas Detector (MPGD). This kind of detector has a very good spatial and time resolution (order of 100 $\mu$m and few ns, respectively) and very low price, making it suitable for a full-body scanner. Further improvement in the time precision (suitable goal is to achieve values of the order of 100 ps) could be reached thanks to the Fast Timing MPGD (FTM) design, where multiple layers of MPGD compete in better measuring time information.
In order to detect PET photons, an additional element is needed: the converter. In this material, photon interacts with matter mostly by Compton effect, producing electrons that drift towards the MPGD where the multiplication step will take place.
In these studies, we show PET photon detection using a FTM, in several configurations, working not only with the numbers of the layers of the MPGD but also with the converter material.
Currently, cancer is one of the most frequent death causes in the world and
radiation therapy is used in approximately 50% of patients diagnosed with
cancer. This implies the need of the treatment to be as efficient and safe
as possible. In this work, a novel reconfigurable Dose-3D detector intended for
a full spatial therapeutic dose reconstruction to improve radiotherapy
treatment planning by providing a breakthrough detector with active voxels
is presented. The device is comprising a customizable detector head, a
scalable data acquisition system (including hardware, firmware and low-level
software) and a state of the art high-level software.
The detector head is being designed as a set of 3D-printed scintillator
pieces, whose shape and arrangement can be changed to accommodate patient's
needs. A feasibility study was done to assure the quality of the detector
manufactured using the aforementioned method. The results show, that the
light output of 3D-printed scintillators provides sufficient signal to noise
ratio for the project.
The data acquisition system (DAQ) is designed to accommodate the changing
geometry by varying the number of slices, each capable of aggregating
64 detection channels into 1 Gbps Ethernet link. The low-level software can
interact with virtually any number of DAQ units. Prototype devices have been
tested successfully with the whole detection chain in place.
The high-level software is being designed to automatically convert medical
data (CT scans) into accurate 3D models of the tumor and neighbouring cells
using machine learning. Obtained geometry will be used to create dedicated
detector head for the patient, as well as an environment for dose simulation
in GEANT.
In conclusion, the research undertaken until now confirm the possibility
to build a device to greatly personalise and improve radiotherapy planning
and effectiveness.
Radiation detection in the environment is of great importance and suitable instruments are highly needed. One possibility for the detection of gamma-ray sources is a Compton gamma camera (CGC) which uses electronic collimation based on the kinematics of the Compton scattering. Most realizations comprise two separate detector planes, a scatterer and an absorber, with some recent attempts to make a single plane CGC in order to enhance compactness and reduce costs. We have designed a novel single plane CGC based on pixelated GaGG scintillators read out by silicon photomultipliers (SiPM). The CGC comprises the scatterer and the absorber layers consisting of 8x8 arrays of 3 mm x 3 mm x 3 mm GaGG scintillator pixels. In the introduced concept, the individual pixels in the scatterer layer are optically coupled to the corresponding pixels in the absorber by the matching 3 mm x 3 mm plexiglass lightguides, and hence both the scatterer and the absorber pixel in one column are readout by the same SiPM. The single-pixel energy resolution is measured to be 12.3% for 662 keV gammas. GEANT4 simulations have been done to estimate the intrinsic efficiency of various detector configurations in dependence on the lightguide length. The angular resolution is estimated from the point-source image reconstructed by the simple back-projection method. The length of 20 mm is chosen for the final design, with an estimated intrinsic efficiency of 0.11% and angular resolution of about 10.5o (FWHM). The first results of the measured characteristics of the detector will be shown. A successful realization of the described detector may be a significant step in the realization of a compact, efficient, cost-effective and easily transportable Compton gamma camera, also with the realistic potential for upgrading to application-specific larger systems comprising more identical modules.
Anatomical changes occurring during proton therapy treatment are considered a relevant source of uncertainty in delivered dose. The INSIDE in-beam Positron Emission Tomography scanner, installed at the National Oncological Center of Hadrontherapy (CNAO), performs in-vivo range monitoring to obtain information about morphological changes in the irradiated tissue. Our purpose is to assess the sensitivity of the INSIDE PET system in detecting anatomical changes using inter-fractional range variations methods.
Eight proton treated patients, enrolled during the first phase of the INSIDE clinical trial at CNAO, were considered. Range variations along the beam direction were estimated using the Most-Likely Shift (MLS) method, which was for the first time applied to in-beam PET images. It was tested on a simulated patient, for which notable anatomical changes occurred, and validated on six patients without and two with anatomical changes. In order to establish the efficacy of the MLS method, we made a comparison with the previously used Beam Eye View (BEV) method. The sensitivity of the INSIDE in-beam-PET scanner in detecting range variation was evaluated by the standard deviation of the range difference distributions for each patient. The range differences obtained were superimposed on the CT scan as colorized maps, which indicate where an anomalous activity range variation was found.
For patients showing no morphological changes, the average range variation standard deviation was found to be 2.5 mm with the MLS method and 2.3 mm with the BEV method. On the other hand, for the two patients where small anatomical changes occurred, we found larger standard deviation values. In the simulated patient case, the standard deviation gradually increases according to the increasing anatomical changes. The changes detected with our range analysis were localized in the same zones as the one observed with the control CT scans.
This work presents a systematic study of multiple counts detection in a Pixirad/Pixie-II detection system. To characterize the dependence of multiple counts from the energy and discriminator threshold, monochromatic photons have been employed. Measurements have been performed at the SYRMEP (SYnchrotron Radiation for Medical Physics) beamline of Elettra synchrotron, Trieste. For each energy, the beam has been attenuated to have a very low fluence rate at the detector. By combining this low fluence filtered-beam with a short acquisition time, the probability of detecting two or more photons in neighboring pixels in a single frame has been made negligible. With this setup, when multiple counts occur, clusters of different sizes (one, two or more adjacent pixels), each induced by a single interacting photon, appear in the recorded images. For each combination of energy and threshold, the number and the size of clusters have been quantified.
Results show that, when photons with energies below the Cd K-edge are employed, the plots of number and size of the detected clusters against the relative thresholds (i.e. Threshold/Energy) are independent from the energy of the impinging photons. In particular, when the relative threshold is set to 0.1, the relative frequencies of clusters corresponding to single, double and triple counts are respectively of 0.4, 0.4 and 0.2. Otherwise, when imaging with photons having energy above Cd K-edge, clusters of more than 4 pixels are observed. In this case, the number and the maximum size of the clusters increase with the energy of the impinging photons.
We compare the performance of gamma-ray detectors based on monolithic BGO crystals versus LYSO ones, using a novel neural-network event characterization algorithm. LYSO represents the gold standard in applications such as Positron Emission Tomography and is considered a key component for time-of-flight (ToF) photon detection. On the contrary, BGO has been used so far only for non-ToF applications because of its long scintillation decay time and low light yield.
The setup consists of a 22Na point source between two detectors composed of a 25.9 mm x 25.9 mm x 12 mm scintillating crystal coupled to Hamamatsu MPPC arrays. The acquired events are reconstructed using a neural network trained with both experimental and simulated data. The experimental data are acquired by moving the detector on a 2 mm step grid, so as to irradiate a regular mesh. The simulated data are obtained by modeling the photon interactions and the optical tracking using Geant4, and subsequently using the timestamp of each detected optical photon to simulate the response of the SiPM arrays. In each scan, about 500 coincidence events are acquired for each point, equally divided between the training and the test sets.
The x and y positions of the interactions in both crystals can be reconstructed with a full width at half maximum (FWHM) of 0.8 mm with either crystal. An energy resolution of 20.2% and 12.7% is obtained for BGO and LYSO, respectively. The time difference distribution between the monolithic and the coincidence detector shows an average coincidence time resolution (CTR) of 320 ps FWHM for BGO and 160 ps for LYSO.
The obtained results show that the performance gap between BGO and the more performant LYSO in terms of CTR can be reduced significantly to the level that BGO becomes a valid alternative for time-of-flight applications.
The use of muon tomography in geoscience, and in glacier monitoring, is being increasingly used, and showed how these detectors can provide insights on relevant topics as the time evolution and dynamics of glacier melting. The latest experiments results present in literature make use of detectors to be placed in tunnels beneath the target of the study. This approach limits the number of glaciers to be studied due to the limited number of places the experiments can take place.
We here present a novel concept for a muon tomography detector to be used in open-sky applications, lightweight, and with limited costs, so that can be used in the field and can be produced in large numbers to provide for a large area monitoring for glacier evolution. The aim of the detector is to measure the directional flux of muons with an angular accuracy better than 0.010 radiants. The results presented show the feasibility and optimization of a detector based on scintillating fibers bundles, read out by silicon photomultipliers. As well we will show the speed of such detector is enough to detect and reject backgrounds muons not transversing the target under study, and is able to measure the ice thickness with resolution of order of 5 meters. This resolution would allow us to measure the seasonal increase and reduction of ice thickness and the melting trend of the glacier under study, and also to monitor the formation of the melting channels inside the glaciers, which are one of the hot topics in the glacier evolution studies.
The application of safety margins in treatment planning to account for possible morphological variations prevent from profit from the particle therapy intrinsic precision. Thus, the development of an in vivo verification system for particle therapy treatments is considered a crucial step forward in improving the clinical outcome, allowing to experimentally check the planned and delivered dose consistency and to re-schedule the treatment when needed. The Dose Profiler is a device designed and built to operate as an in vivo verification system of the carbon ion treatments, exploiting the secondary charged fragments escaping from the patient body. The capability of spotting morphological variations of the Dose Profiler has been investigated for pathologies of the neck-head district in the context of a clinical trial (ClinicalTrials.gov Identifier: NCT03662373) carried on at CNAO (Centro Nazionale di Adroterapia Oncologica, Pavia, Italy) from the INSIDE collaboration. The measured fragment 3D emission map has been compared computing the gamma-index after each monitored fraction to spot possible modifications. The results obtained analysing the full patient sample are presented in details the potential in detecting the insurgence of morphological changes in clinical condition detecting charged fragments is discussed.
Currently PSI delivers the most intense continuous muon beam in the world with up to few 10^8 μ+/s and aims at keeping its leadership upgrading its beamlines within the HIMB project to reach intensities up to 10^10 μ+/s, with a huge impact for low-energy, high-precision muon based searches.
Here we present two novel beam monitors designed for the current PSI beams and that will be upgraded for the HIMB operations: the scintillating fiber (SciFi) detector, a grid of scintillating fibers coupled to SiPMs, and the MatriX detector, a matrix of plastic scintillators coupled to SiPMs.
The advantage of these highly segmented detectors is to be able to withstand high magnetic fields (up to 1.25 T) and to measure the full beam rate at once.
The final version of the SciFi detector is going to be assembled in 2022 to be included permanently along the MEG II beamline and it will include an insertion system to perform measurements at demand. As a grid of fibers it is quasi non-invasive and 80 % of the beam passes through without being affected by the detector: it could be used for real time monitoring of the muon beam during data taking. It is able to perform particle ID through energy deposition and TOF measurement.
The final version of the MatriX detector is going to be assembled in 2022. It is thought to be used for beam tuning in high magnetic field environment and can easily be redesigned to fit space requirements. A major upgrade from the prototype will be the use of thinner scintillators, from 2 mm to 250 um in thickness, and the introduction of a plexiglas light guide between the scintillator and the sensor to stop low energy particles and increase separation with MIPs.
The performances of these detector as measured along the beamline, their detailed MC simulations and the beam characteristics will be presented.
The Low-Temperature Cofired Ceramic (LTCC) technology is known as a highly suitable material for the production of electronic microstructures in 3D. In particular, the material is characterized by good mechanical and electrical properties, a wide range of operating temperatures, high thermal conductivity and low outgassing. Additionally, the high radiation resistance of such materials has been already confirmed. Such a combination of parameters makes LTCC an excellent candidate for High Energy Physics (HEP) applications. The preliminary tests have been already conducted at Wroclaw University of Science and Technology concerning manufacturing Gas Electron Multiplier (GEM) amplification elements as well as readout plates. The first LTCC-GEM prototypes have been manufactured, and the results are presented. Research is continued to improve their parameters as well as produce microstructures with diameters that are difficult to obtain by standard "wet etching" techniques. It is anticipated that the developed technology will be used for specialized applications and the production of prototype systems or small series.
The ORIGIN project (Optical Fiber Dose Imaging for Adaptive Brachytherapy), supported by the European Commission within the Horizon 2020 framework program, targets the production and qualification of a real-time radiation dose imaging and source localization system for both Low Dose Rate (LDR) and High Dose Rate (HDR) brachytherapy treatments, namely radiotherapy based on the use of radioactive sources implanted in the patient’s body.
This goal will be achieved through a 16 fiber sensor system, engineered to house in a clear-fiber tip a small volume of the scintillator to allow point-like measurements of the delivered dose. The selected scintillating materials feature a decay time of about 500 μs and the signal associated with the primary γ ray interaction results in the emission of a sequence of single photons distributed in time. Therefore, the operation requires a detector with single-photon sensitivity a system designed to provide dosimetry by photon counting. The instrument being developed is based on Silicon Photomultipliers (SiPMs), with a solution fully qualified on a single fiber prototype and currently scaled-up relying on the CITIROC1A ASIC by WEEROC, embedded in the FERS-DT5202 scalable platform designed by CAEN S.p.A.
The paper presents the laboratory qualification of the system in terms of response uniformity, stability, and reproducibility. Moreover, the commissioning and assessment in a clinical environment, both for Low and High Dose brachytherapy will be discussed. The measurements performed in the laboratory using an X-ray cabinet show that the uncertainty due to fiber positioning, fiber non-uniformity, and geometry acceptance is less than 1 %. According to the laboratory measurements results and taking into account the fiber non-uniformity, the source position can be obtained from the measurements in the hospital with the precision required by ORIGIN's project specifications.
Resistive plate chambers (RPCs) with electrodes of high-pressure phenolic laminate (HPL) and small gas gap widths down to 1 mm provide large area tracking at relatively low cost in combination with high rate capability and fast response with excellent time resolution of better than 500 ps. These chambers offer a wide range of applications. In particular, they are perfectly suited for experiments requiring sub-nanosecond time resolution and spatial resolution on the order of a few millimeters over large areas. Thin-gap RPCs will therefore be employed in the upgrade of the barrel muon system of the ATLAS experiment at HL-LHC and are candidates for the instrumentation of future collider detectors and for experiments searching for long-lived particles in experiments. RPCs are also frequently used in large area cosmic ray detectors. The large demand for RPCs exceeds the presently available production capacities. At the same time, the requirements on mechanical precision, reliability and reproducibility for collider detectors have increased. Additional suppliers with industry-style quality assurance are urgently needed. We have established RPC production procedures compliant with industrial requirements and are in the process of certifying several companies for RPC production for the ATLAS upgrade for HL-LHC and beyond. We will report about the technology transfer, the RPC prototype production at the selected companies and the results of the certification procedure.
We propose a gamma-ray detection module for the development of a SPECT system for real-time dose monitoring in Boron Neutron Capture Therapy (BNCT). BNCT is a radiotherapy technique where the tumor volume is loaded with boron-10 and irradiated with thermal neutrons. Boron neutron capture reactions occur, and they deposit their energy within the tumor cells, thus sparing normal cells. Moreover, the B-10(n, α)7Li reactions create gamma rays at 478 keV, and their detection can be used to quantify and localize the dose delivered to the patient. However, this detection is very challenging because of the mixed radiation field present during BNCT irradiations and the low 10B concentration. We report here about the performance of the BeNEdiCTE (Boron Neutron CapTurE) module, based on a 2 inches cylindrical LaBr3(Ce+Sr) scintillator crystal, optically coupled to a matrix of Silicon Photomultipliers (SiPMs), when irradiating 10B-loaded samples with neutrons. Vials filled with different boron concentrations have been irradiated in the TRIGA MARK II nuclear reactor of Pavia University (Italy), and spectra have been acquired with the BeNEdiCTE module, wrapped in cadmium foils to avoid the neutron activation of the detector. The excellent energy resolution of the module (<3% at 662 keV) allows to resolve the photopeak of the boron neutron capture events at 478 keV. Very good linear correlation between the number of events detected at 478 keV and the boron concentration has been achieved, down to 62 ppm, with a neutron flux of approximately 10^5 n/cm2/s.
Traditional thermal neutron detectors are based on Helium-3 as conversion and detection material due to its large neutron cross-section.
In light of the upgrade and construction of several neutron scattering facilities such as the European Spallation Source (ESS) and a simultaneous shortage of Helium-3, new detection technologies have been introduced. The most prominent one is to use solid converts with a large thermal neutron cross-section such as Gadolinium and Boron. Those material emit charged particles when hit by a neutron. The technique then relies on detection and/or tracking of the charged particle, as in detectors of particle physics. At the same time, this requires an increase of the readout channels by an order of magnitude with the advantage to also increase the position resolution by the same amount compared to traditional neutron detectors. A prime example is the Gadolinium Gas Electron Multiplier (GdGEM) detector for the NMX instrument at ESS jointly developed by the CERN Gaseous Detector Group and the ESS Detector Group.
In this contribution, some of our efforts to transfer particle physics detector and readout electronics to neutron science will be presented.
We employed the VMM chip, originally designed for the ATLAS New Small Wheel upgrade, to read out a GEM-based neutron detector. The Timepix3 chip is employed in a neutron Time Projection Chamber as well as to read out a neutron sensitive Micro-Channel Plate detector. Those readout chips are integrated in the Scalable Readout System of the RD51 collaboration.
Here we present an overview of Jagiellonian University's PET scanner versions and their performances. Independent J-PET detector variations are barrel J-PET, Modular J-PET, and Total-Body Jagiellonian-PET (TB J-PET) concept. Experimental results from the J-PET barrel and the modular J-PET will be presented, while the project of TB J-PET will be conveyed through GATE simulations [1,2].
Our objective is to develop a cost-effective positron emission tomograph with capabilities of simultaneous PET/CT and PET/MR imaging and diagnosis. J-PET detectors are the first of their kind made up of plastic scintillators and have only digital front-end electronic circuits and a triggerless data acquisition system. A Modular J-PET prototype is made and tested as a first step in building a total body J-PET tomograph. An axial arrangement of strips of plastic scintillators, which have a minimal light attenuation, exceptional timing qualities, and the possibility of cost-effectively increasing the axial field-of-view, opens promising aspects for a low-cost construction of a total-body PET scanner [3]. TB J-PET is based on the novel idea of plastic scintillators in conjunction with wavelength shifters (WLS) to improve the axial resolution of the scanner [4]. The TB-J-PET estimated sensitivity and NECR are higher than those of existing commercial PET systems, making it an alternative for the wide range of clinical applications of total-body PET scanners.
Geometries, electronics, and the use of WLS are the main components that differentiate the detectors. The system and elaborated calibration methods, including the first results of the image reconstruction, will be presented on the basis of experimental and simulation results.
References:
[1] Moskal et al., Sci. Adv. 7 : eabh4394, (2021).
[2] P.Moskal et al., Nature Communications 12, 5658 (2021).
[3] P. Moskal, et al., IEEE Trans Instrum Meas, vol. 70,( 2021).
[4] J. Smyrski, et al., BioAlgorithms and Med-Systems 10, 59 (2014).
Recent developments in semiconductor pixel detectors allow for a new generation of positron-emission tomography (PET) scanners that, in combination with advanced image reconstruction algorithms, will allow for a few hundred microns spatial resolutions. Such novel scanners will pioneer ultra-high-resolution molecular imaging, a field that is expected to have an enormous impact in several medical domains, neurology among others.
The University of Geneva, the Hôpitaux Universitaires de Genève, and the École Polytechnique Fédérale de Lausanne have launched the 100µPET project that aims to produce a small-animal PET scanner with ultra-high resolution. This prototype, which will use a stack of 60 monolithic silicon pixel sensors as a detection medium, will provide volumetric spatial resolution one order of magnitude better than today’s best operating PET scanners.
The R&D on the optimisation of the monolithic pixel ASIC, the readout system and the mechanics, as well as the simulation of the scanner performance, will be presented.
Alto Ritmo Concert
Jacopo Taddei (sax) & Samuele Telari (accordion)
The Mu2e experiment at Fermilab searches for the neutrino-less conversion of a negative muon into an electron, with a distinctive signature of a mono-energetic electron with energy of 104.967 MeV. Mu2e aims to improve by four orders of magnitude with respect to the current best limit.
The calorimeter plays an important role to provide excellent particle identification capabilities and an online trigger filter while improving the track reconstruction capabilities, asking for 10% energy resolution and 500 ps timing resolution for 100 Mev electrons. It consists of two disks, each one made by 674 un-doped CsI crystals, read out by two large area UV-extended SiPMs.
In this talk, we present the status of construction and the QC performed on the produced crystals and photosensors, the development of the rad-hard electronics and the most important results of the irradiation tests done on the different components from crystals to SIPMs and electronics. Irradiation has been carried out with ionising doses, neutrons and protons.Production of electronics is now underway.We summarize the QC in progress on the analog electronics and on the integrated SIPM+FEE units. Construction of the mechanical parts are also well underway. Status and plans for the final assembly and commissioning
are described.
A large calorimeter prototype (dubbed Module-0) has been tested with an electron beam between 60 and 120 MeV at different impact angles and the obtained results are reported. A full vertical slice test with the final electronics is in progress on Module-0 at the Frascati Cosmic Rays test setup. Stability of response and calibration results are shown.
The existing CMS endcap calorimeters will be replaced with a High Granularity Calorimeter (HGCAL) for operation at the High Luminosity (HL-LHC). Radiation hardness and excellent physics performance will be achieved by utilising silicon pad sensors and SiPM-on-scintillator tiles with high longitudinal and transverse segmentation. One of the major challenges of the HL-LHC will be the high pileup environment, with interaction vertices spread by a few centimetres, equivalent to a few 100ps in time. In order to efficiently reject particles originating from pileup, the HGCAL is designed to provide timing measurements for individual energy depositions with signals above an equivalent of 10 MIPs. By this means, precision timing information at the order of 30ps for clusters beyond 5 GeV will be achieved. Given the complexity and size of the system, this poses a particular challenge to the readout electronics as well as to the calibration and reconstruction procedures. Recently, the proof-of-principle of the envisaged concept could be demonstrated using experimental data of more than 100 time-calibrated readout channels of an HGCAL prototype tested with particle beam in 2018.
In this contribution, we present the general challenges for the front-end electronics in the final design, the recent proof-of-concept with the HGCAL prototype in test beam, as well as the anticipated timing performance from simulation at HL-LHC.
Progress in experimental high-energy physics has been closely tied to developments of high-performance calorimeters. Since their invention, crystal calorimeters have consistently achieved the best resolution for measurements of the energies of electromagnetic (e.m.) particles (electrons and photons). Recently, we experimentally demonstrated the possibility to significantly accelerate the e.m. shower development inside a lead tungstate (PWO) crystal, when the incident beam is aligned with the crystal axes within some tenths of a degree. Here, we present the results obtained at the H2 line of CERN SPS with a hundred-GeV electron beam with different PWO samples (0.5, 1 and 2 radiation length thick), coupled with SiPM for direct measurement of scintillation light enhancement in case of beam alignment to the main crystal axes. This is indeed the first direct measurement of scintillation light enhancement due to shower acceleration caused by the strong axial field. Since the angular acceptance of the crystal strong field depends little on particle energy, while instead the decreasing of the shower length remains pronounced at very high-energy, a crystal based calorimeter on oriented crystals would feature a consistent compactness enhancement while rivaling the current state of the art in terms of energy resolution in the range of interest of present and future forward detectors, beam dumps for light dark matter search and source-pointing space-borne $\gamma$-ray telescopes.
The project of a Multi-TeV Muon Collider represents a unique opportunity to explore the high energy physics frontier and to measure with high precision the Higgs coupling with the other particles of the Standard Model as well as the Higgs self-coupling, in order to confirm the results already achieved in the SM and possibly to find evidences for new physics. One of the major challenges for the design and optimization of the technologies suitable for a Muon Collider experiment is represented by the high background induced by the decay of the muons coming from the beam.
This contribution will present the design of an innovative MPGD-based hadronic calorimeter.
The detector consists of a sampling calorimeter exploiting MPGDs as active layers: the MPGDs offer a fast and robust technology for high radiation environments and a high granularity for precise spatial measurements. Moreover, the detector is designed to optimize the jet reconstruction and for background suppression. The calorimeter is simulated using the Geant4 toolkit to support the detector R&D. The detector design and layout optimization supported by the simulation will be presented.
We are developing a new type of electromagnetic calorimeter based on a SiW sampling design using silicon pixel sensors with digital readout. The R&D is performed in the context of the Forward Calorimeter upgrade proposal within the ALICE experiment and is strongly related to studies of imaging in proton CT; it is equally applicable to other future collider projects such as EIC, ILC, CLIC or FCC. Based on experience with a first full prototype of a digital calorimeter, which demonstrated a proof of principle, we have constructed an advanced second prototype, EPICAL-2, which makes use of the Alpide MAPS sensor developed for the ALICE ITS upgrade. A binary readout is possible due to the pixel size of $\approx 30 \times 30 \, \mu \mathrm{m}^2$. The prototype consists of alternating W absorber and Si sensor layers, with a total thickness of ~20 radiation lengths, an area of $\mathrm{30mm\times30mm}$, and ~25 million pixels. This prototype has been successfully tested with cosmic muons and with test beams at DESY and the CERN SPS.
We will report on performance results obtained at DESY, showing good energy resolution and linearity, and compare to detailed MC simulations. We will also show preliminary results of shower-shape studies with unprecedented spatial precision and of the high-energy performance as measured at the SPS.
A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is part of the design of the ECAL for many detectors conceived future Higgs factories, in particular for the International Large Detector (ILD) concept, one of the two detector concepts for the detector(s) at the future International Linear Collider.
Prototypes for this type of detector are developed within the CALICE Collaboration.
The technological prototype features integrated front-end electronics or compact layer and readout design.
During 2019-20 a stack of 15 layers with a dimension of ~$250×180×10\,{\rm mm^3}$ each was assembled, for a record number of 15360 cells, one of biggest for this type of calorimeters. A beam test at DESY has been carried out in November 2021 and a second one is scheduled for March 2022. These tests will allow for first detailed tests in terms of energy resolution and linearity but also in terms of homogeneity and efficiency of the individual layers and cells. The beam test will be a proof for the feasibility of the application of a highly compact readout system that in terms of compactness meets already the needs for detector systems at future Higgs factories. At the Pisa Meeting we will present first beam test results and the status of the implementation in simulation.
In 2021/22 we have developed a new version of detector layers that notably will be optimised for power pulsing with an innovative local storage of power for the readout ASICs. The results of first tests with these layers will be available at the time of the Pisa Meeting.
Note finally that for 2022 and 2023 large scale beam test campaigns with CALICE prototypes of hadronic calorimeters are planned. The common readout of the SiW-ECAL with the CALICE Analogue HCAL will be tested in March 2022.
The Mu2e experiment at Fermi National Accelerator Laboratory (Batavia, Illinois, USA) searches for the charged-lepton flavor violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The dynamics of such a process is well modelled by a two-body decay, resulting in a mono-energetic electron with energy slightly below the muon rest mass (104.967 MeV). Mu2e will reach a single event sensitivity of about 3x10−17 that corresponds to four orders of magnitude improvement with respect to the current best limit.
The calorimeter plays an important role to provide excellent particle identification capabilities and an online trigger filter while aiding the track reconstruction capabilities, asking for 10% energy resolution and 500 ps timing resolution for 100 Mev electrons. It consists of two disks, each one made by 674 un-doped CsI crystals, read out by two large area UV-extended SiPMs. In order to match the requirements of reliability, a fast and stable response, high resolution and radiation hardness (100 krad, 10^12 n/cm^2) that are needed to operate inside the evacuated bore of a long solenoid (providing 1 T magnetic field) and in the presence of a really harsh radiation environment, fast and radiation hard analog and digital electronics has been developed. To support these crystals, cool down the SiPMs and support and dissipate the electronics heat power, a sophisticated mechanical and cooling system has been also designed and realized.
We describe the mechanical details, design and performances along with the assembly status of all the calorimeter components and its integration in the Mu2e Experiment.
The Crilin calorimeter is a semi-homogeneous calorimeter based on Lead Fluoride (PbF2) Crystals readout by surface-mount UV-extended Silicon Photomultipliers (SiPMs). It is a proposed solution for the electromagnetic calorimeter of the Muon Collider. A high granularity is required in order to distinguish signal particles from the background and to solve the substructures necessary for jet identification. Time of arrival measurements in the calorimeter could play an important role, since large occupancy due to beam-induced backgrounds is expected, and the timing could be used to assign clusters to the corresponding interaction vertex. The calorimeter energy resolution is also fundamental to measure the kinematic properties of jets. Moreover, the calorimeter should also operate in a very harsh radiation environment: 10 Mrad/year total ionizing dose (TID) and a 10^14 1MeVeq/cm^2 neutron fluence.
In June 2021, a dedicated test beam was performed at the Beam Test Facility (BTF) of the INFN-LNF with electrons. The timing resolution, evaluated as the time difference of the two SiPMs as a function of the collected energy, shows a sigma below 300 ps for deposited energy in the range 150-500 MeV. Another test beam has been performed at H2 at CERN in August 2021 with electrons of energy between 20 and 120 GeV and with 150 GeV muons. Analysis results will be shown: a timing resolution better than 100 ps has been achieved for deposited energies greater than 1 GeV. The first radiation tolerance studies and the development and tests of the small size prototype (Proto-0) are reported along with the relative results.
A bigger prototype (Proto-1), made of two layers of 3x3 PbF2 crystals each, will be realized in 2022, aiming at a temperature operation of 0/-20 degrees; this calorimeter will be qualified at a dedicated test beam at Cern before the end of 2022.
The Liquid Argon Calorimeters are employed by ATLAS for all electromagnetic calorimetry and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. It also provides inputs to the first level of the ATLAS trigger. After successful period of data taking during the LHC Run-2 the ATLAS detector entered a long shutdown period starting 2019. In 2022 the LHC Run-3 should see an increased pile-up of 80 interactions per bunch crossing. To cope with this harsher conditions, a new trigger path have been installed during the long shutdown. This new path should improve significantly the triggering performances by increasing by a factor of ten the number of available units of readout at the trigger level.
The installation of this new trigger chain required the update of the legacy system to cope with the new components. It is more than 1500 boards of the precision readout that have been extracted from the ATLAS pit, refurbished and re-installed. For the new system 124 new on-detector boards have been added. Those boards are able to digitize at 40 MHz the calorimeter signal in a radiative environment. The digital signal is then processed online to provide the measured energy for each unit of readout which corresponds to 31Tbps of data. To minimize the triggering latency the processing system had to be installed underground. There the limited space available imposed the need of a very compact hardware structure. For this large FPGAs with high throughput have been mounted on ATCA mezzanine boards. Given that modern technologies have been used compared to the previous system, all the monitoring and control infrastructure had to be adapted.
This contribution should present the challenges of such installation, what have been achieved and the first results with the new system including calibration and data taking performance.
Noble liquid calorimetry is a well proven technology that successfully operated in numerous particle physics detectors (D0, H1, NA48, NA62, ATLAS, …). Its excellent energy resolution, linearity, stability, uniformity and radiation hardness as well as good timing properties make it a very good candidate for future hadron and lepton colliders. Recently, a highly granular noble liquid sampling calorimeter was proposed for a possible FCC-hh experiment. It has been shown that, on top of its intrinsic excellent electromagnetic energy resolution, noble liquid calorimetry can be optimized in terms of granularity to allow for 4D imaging, machine learning and - in combination with the tracker measurements - particle-flow reconstruction. This talk will discuss the ongoing R&D to adapt noble liquid sampling calorimetry for an electromagnetic calorimeter of an FCC-ee experiment with a focus on signal extraction, noise mitigation and cryostat material budget. First electrical tests on a high granularity PCB prototype and performance studies realized with the FCCSW full simulation framework will also be presented.
The Mu2e experiment at Fermilab aims to search for the SM forbidden process of muon to electron conversion in the Coulomb field of Al nuclei. The signal signature consists of 104.96 MeV monoenergetic
conversion electrons, identified by a complementary
measurement carried out by a very precise straw-tube tracker and an electromagnetic calorimeter.
The calorimeter is composed of 3.4×3.4×20 cm$^3$ undoped CsI crystals, each one
coupled to two custom UV-extended Mu2e-SiPMs, arranged in two annular disks for a total of 1348 elements, to achieve high granularity and high resolution in energy ($<10\%$) and timing ($<500$ ps) for 100 MeV electrons. In order to calibrate the calorimeter with cosmic ray muons in the assembly area, we have designed and realized a Cosmic Ray Tagger (CRT) at Laboratori Nazionali di Frascati (LNF) of INFN.
The CRT consists of two planes of eight 2.5x1.5x160 cm$^3$ plastic scintillator (EJ-200) bars, each one coupled to Mu2e-SiPMs on both edges to reconstruct the hit position by their time difference. A template fit algorithm is used for timing reconstruction of both sensors of each bar, achieving position measurements in the longitudinal direction, with a resolution $\sigma_Z<1.5$ cm, as measured with dedicated runs where a 1x1 cm$^2$ scintillator is used as external trigger. The 2D reconstruction of the hits in the two modules, placed one above and one below the calorimeter disk, allows to track muons in 3D.
The selected tracks are finally used to equalise and calibrate the energy response of all calorimeter channels to a level below 1$\%$ using the MIP energy deposition. The CRT will also be employed to estimate the dependence of energy and time response and resolution along the crystal longitudinal coordinate. A first test will be carried out at LNF on the 51 crystals arranged in the large size calorimeter prototype named Module-0.
The Mu2e experiment at Fermilab will search for the Standard Model forbidden conversion of a negative muon into an electron and the calorimeter is an important part of this experiment. It is based on undoped CsI crystals, each one read by two custom-made arrays of UV-extended Silicon Photomultipliers (SiPMs). Two SiPMs glued on a copper holder and two independent Front End Electronics (FEE) boards, coupled to each SiPM, form a Readout Unit (ROU). To ensure consistency and reliability of the ROUs, we have built an automated Quality Control (QC) station to test them.
The QC station is located at LNF (Laboratori Nazionali di Frascati) and can test two ROUs at the same time.
The SiPMs are exposed to the light of a 420 nm pulsed LED attenuated by means of an automated nine-positions filter-wheel. The transmitted light is diffused on the SiPMs surface using a box with sanded glass that also provides light tightness and allows to have a controlled environment, ensuring good reproducibility of the measurements. The ROUs are held in place by an aluminum plate that serves also as a conductive medium for temperature stabilization.
The ROUs are powered by a low voltage and a high voltage supply controlled remotely. The data acquisition of the FEE signals is handled by a Mezzanine Board and a Master Board (Dirac) USB-controlled with Python and C++ programs. The data acquisition has been parallelized and 10000 events per wheel position can be acquired in around one minute.
A scan at different light intensities is performed for each of the selected supply voltages, V$_{i}$, around the SiPM operational voltage, V$_{op}$, thus allowing to reconstruct the response, gain, photon detection efficiency and their dependence on V$_{i}$-V$_{op}$. We will present the first results obtained on a large sample of production ROUs and the achieved reproducibility.
The Tile Calorimeter (TileCal) is a sampling hadronic calorimeter covering the central region of the ATLAS experiment, with steel as absorber and plastic scintillators as active medium. The High-Luminosity phase of LHC, delivering five times the LHC nominal instantaneous luminosity, is expected to begin in 2029. TileCal will require new electronics to meet the requirements of a 1 MHz trigger, higher ambient radiation, and to ensure better performance under high pile-up conditions. Both the on- and off-detector TileCal electronics will be replaced during the shutdown of 2026-2028. PMT signals from every TileCal cell will be digitized and sent directly to the back-end electronics, where the signals are reconstructed, stored, and sent to the first level of trigger at a rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. The modular front-end electronics feature radiation-tolerant commercial off-the-shelf components and redundant design to minimise single points of failure. The timing, control and communication interface with the off-detector electronics is implemented with modern Field Programmable Gate Arrays (FPGAs) and high speed fibre optic links running up to 9.6 Gb/s. The TileCal upgrade program has included extensive R&D and test beam studies. A Demonstrator module with reverse compatibility with the existing system was inserted in ATLAS in August 2019 for testing in actual detector conditions. The ongoing developments for on- and off-detector systems, together with expected performance characteristics and results of test-beam campaigns with the electronics prototypes will be discussed.
TileCal, the central hadron calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC), is readout by about 10,000 photomultipliers (PMTs). Earlier studies of performance showed a degradation in PMTs response as a function of the integrated anode charge. At the end of the High-Luminosity LHC (HL-LHC) program, the expected integrated charge for PMTs reading out the most exposed cells is 600 C. A model of the evolution of the PMT response as a function of the integrated charge, based on the measurement response during the Run 2, was built. The projected loss at the end of the HL-LHC is 25% for 8% of the total TileCal PMTs. These PMTs will be replaced with a newer version, in order to keep the global detector performance at an optimal level. A local test setup is being used in the Pisa laboratory to study the long term response of the new PMT model considered for replacement in the TileCal readout of most exposed calorimeter cells. Furthermore, the performance of the new is compared to the old PMT model, the current version used to readout TileCal cells. For the first time this new PMT model has been tested after integrating more than 300 C of anode charge. Preliminary results obtained from data collected in the Pisa laboratory over a period exceeding six moths are shown in this presentation.
The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the LHC. It is made of steel plates acting as absorber and scintillating tiles as active medium. The TileCal response is calibrated to electromagnetic scale by means of several dedicated calibration systems.
The accurate time calibration is important for the energy reconstruction, non-collision background removal as well as for specific physics analyses. The initial time calibration using so-called splash events and subsequent fine-tuning with collision data are presented. The monitoring of the time calibration with laser system and physics collision data is discussed as well as the corrections for sudden changes performed still before the recorded data are processed for physics analyses. Finally, the cell time resolution as measured with jet events in Run 2 is presented.
The CMS Collaboration is preparing to build replacement endcap calorimeters for the HL-LHC era. The new high-granularity calorimeter (HGCAL) is, as the name implies, a highly-granular sampling calorimeter with 47 layers of absorbers (mainly lead and steel) interspersed with active elements: silicon sensors in the highest-radiation regions, and scintillator tiles equipped with on-tile SiPMs in regions of lower radiation. The active layers include copper cooling plates embedded with thin pipes carrying biphase CO2 as coolant, front-end electronics and electrical/optical services. The scale and density of the calorimeter poses many engineering challenges that we discuss here. These include: the design & production of 600 tonnes of stainless-steel absorber plates to very high physical tolerances; the development of the CO2 cooling system to maintain each 220-tonne endcap at -35oC whilst the electronics dissipate up to 140kW; the need to cantilever the calorimeters from the existing CMS endcap disks, using titanium wedges; the production of a thin but strong inner cylinder to take the full weight but have little impact on physics performance; the development of low-power high-dynamic-range front-end electronics for over 6 million detector channels; the integration of all services in a volume of only a couple of mm in height.
We give an overview of the design of HGCAL, focusing on the materials and techniques being used to overcome the many challenges for this world’s first calorimeter of its type at a hadron collider.
The reconstruction of electrons and photons in CMS depends on topological clustering of the energy deposited by an incident particle in different crystals of the electromagnetic calorimeter (ECAL). These clusters are formed by aggregating neighbouring crystals according to the expected topology of an electromagnetic shower in the ECAL. The presence of upstream material causes electrons and photons to start showering before reaching the ECAL. This effect, combined with the 3.8T CMS magnetic field, leads to energy being spread in several clusters around the primary one. It is essential to recover the energy contained in these satellite clusters to achieve the best possible energy resolution. Historically, satellite clusters have been associated to the primary cluster using a purely topological algorithm which does not attempt to remove spurious energy deposits from additional pileup interactions (PU). The performance of this algorithm is expected to degrade during LHC Run 3 (2022+) because of the larger average PU levels and the increasing levels of noise due to the ageing of the ECAL detector. New methods are being investigated that exploit state-of-the-art deep learning architectures like Graph Neural Networks (GNN) and self-attention algorithms. These more sophisticated models improve the energy collection and are more resilient to PU and noise. This talk will cover the challenges of training the models and the opportunities that this new approach offers.
The FoCal-E detector is a part of the FoCal detector aiming to provide unique capabilities to measure small-x gluon distributions via prompt photon production. It represents an upgrade to the ALICE experiment, and will be installed during LS3 for data taking in 2027–2029 at the LHC.
This detector is composed of a Si+W sampling calorimeter hybrid design combining two different Si (Silicon) readout technologies: Pad layers and Pixel layers.
A first prototype is under development to demonstrate the performance of the proposed readout electronics. It is composed of 18 single E-pad boards and 2 MAPS layers. They are all connected via an interface board to an aggregator system. Each single E-pad contains 72 Si-pixel sensors and a front-end ASIC (HGCROC). This ASIC ensures that the response of each sensor is read out using an integrated charge sensitive amplifier-shaper and an analog to digital conversion system (few fC up to 10 pC) enabling the transmission of data on a standard digital connection. This board also contains probes to monitor the temperature, the power consumption and a local power converter to provide clean power supplies. The aggregator board is used to gather the data and trigger information from the detector (data rate of 1,28 Gb/s). It is based on an FPGA allowing the extraction of data via multiple supports.
This prototype is firstly used to validate the choice of the ASIC with the design of a testing board capable of emulating the response of the Si-sensors while developing the aggregator board and its associated firmware and software. It allows also measuring the performances of this system: measurements under beam and through a cosmic test for the measurements of the MIP. Results are used to optimize the design of the final E-pad modules and to finalize the aggregator system.
Jets play a central role in many physics analyses. Initially jets based on topological clusters (Topo jets) using only the calorimeter information have been used. In the last years, jets reconstructed with the Particle-Flow algorithm (PFlow jets), leveraging also the tracking information, found increasing application. It is thus necessary to test if the calibration methods applied to Topo jets can also be used for PFlow jets in ATLAS. Two different studies will be discussed.
First of all, estimating the uncertainty on the Jet-Energy-Scale (JES) calibration at very high pT (pT > 2 TeV) by using the calorimeter response to single particles (single particle uncertainties) is studied. It is found to be very well applicable to PFlow jets in this pT regime. Further, a good agreement between data and Monte Carlo simulation is observed, which is stable with respect to $\eta$ as well as pT.
Secondly, the performance of the Local Hadron Calibration (LCW) for PFlow jets (LCPFlow) is investigated. It aims at correcting for the difference in the calorimeter response to processes at the electromagnetic and hadronic scale. This yields very promising results as well: Overall, a better agreement of LCPFlow jets with truth jets is found compared to PFlow jets at the electromagnetic scale (EMPFlow jets). On top of that, LCPFlow jets show an overall better resolution.
The Light-only Liquid Xenon (LoLX) experiment is designed to study the properties of light emission and transport in liquid xenon (LXe) using silicon photomultipliers (SiPMs). In addition, we also plan to perform long-term stability studies of the SiPMs in LXe. Another important goal of the LoLX experiment is to characterize and utilize the differences in the timing of Cherenkov and scintillation light production to develop a background discriminator for low-background LXe experiments such as, neutrino-less double beta decay searches. The first phase of LoLX is operational and consists of an octagonal 3D-printed structure housing 24 Hammamtsu VUV4 SiPM modules, for a total of 96 individual SiPM channels. The LoLX structure is placed in a cryostat that allows for the liquefaction of Xe along with a Sr-90 beta-emitter placed at the center of the LoLX detector volume. The beta decay electrons on interaction with LXe produce Cherenkov and scintillation light to be studied using LoLX. This talk will cover the current status of the LoLX experiment and present the results obtained from the first runs of the experiment. This data-taking campaign focused on validating the optical transport simulations of LoLX done in GEANT4 by the collaboration. In addition, the effect of external cross-talk (eXT) between the SiPMs was also explored. The DAQ system has been recently upgraded with a GSPS ADC, allowing for improved timing resolution of the light signals.
Several future Higgs factories based on the electron-positron collider are planned for precision Higgs physics to search for the new physics beyond the Standard Model. The calorimeters with the high granularity play a crucial role on the precision Higgs measurement. Especially the high granularity of the cell size of the $5~\mathrm{mm}\times5~\mathrm{mm}$ is required for the electromagnetic calorimeter.
The Scintillator Electromagnetic CALorimeter (Sc-ECAL) is one of the technology options for the ECAL at the future Higgs factories. It is based on a scintillator strip readout by a Silicon Photomultiplier (SiPM) to realize the $5~\mathrm{mm}\times5~\mathrm{mm}$ cell size by aligning the strips orthogonally in x-y configuration. In order to demonstrate the performance of the Sc-ECAL and the scalability to the full-scale detector, the technological prototype has been developed with the full 30 layers.
The commissioning of the prototype is based on long-term tests with LED and cosmic-ray. The per-channel calibrations are successfully done for the key parameters of the Sc-ECAL. It is found that the Sc-ECAL can be properly calibrated and operated.
The performance of the Sc-ECAL is evaluated. The key parameters are successfully monitored and it is found that most of the parameters show excellent stabilities over a long period. The efficiency and position resolution are found to be consistent with the Monte Carlo simulation, and the position resolution meets the requirement of the cell size of $5~\mathrm{mm}\times5~\mathrm{mm}$. The shower analysis is performed using the cosmic-ray. The showers induced by the cosmic-ray are successfully measured as expected in the simulation.
In conclusion, the Sc-ECAL is found to be a promising and mature technology for the highly granular calorimeter to achieve the precision physics at the future Higgs factories.
The MEG II experiment searches for $\mu \rightarrow e \gamma$ decay which is one of the charged lepton flavor violation decays, and the discovery of the decay will be a clear evidence of new physics beyond the Standard Model. The liquid xenon (LXe) gamma-ray detector to precisely measure the energy, position, and timing of the gamma-ray from $\mu \rightarrow e \gamma$ is a key to the unprecedented sensitivity of the MEG II experiment. The LXe scintillation light is read out by VUV-sensitive photosensors (4092 SiPMs and 668 PMTs) specially developed for the MEG/MEG II LXe detector. In 2021, a full commissioning of the LXe detector with all the channels read out was carried out for the first time, and a pilot physics run was also performed in the beamtime 2021. The detector response was monitored using a muon beam and several calibration sources, and the timing and energy resolutions were measured using the gamma-rays whose energies are around the signal energy from the $\pi^0$ decays after charge exchange reactions of charged pions in a liquid hydrogen target. The performance of the entire LXe detector depending on the gamma-ray interaction points was evaluated. Further investigations were performed about the degradation of the photosensor sensitivity by radiation damage found in the previous years. The MEG II LXe detector has been successfully commissioned and is now ready for the long physics run of the MEG II starting in 2022. In this presentation, the performance of the LXe detector measured in the commissioning will be reported.
The MEGII experiment searches for the μ+ → e+γ decay with a sensitivity of 6*10-14 at 90% C.L. The precise measurement of the kinematical variables of the two particles in the final state, generated by muons stopped in a thin target, is key in finding the signature of this process. A major upgrade has been carried out over the last years and a new Liquid Xenon (LXe) calorimeter has been introduced, equipped with both PMT and SiPM immersed in Xenon collecting the Xe scintillation light emitted in the Vacuum Ultra Violet region.
MEGII has successfully completed the eng. run and just started data taking.
The characterization of the 1000 L LXe calorimeter is a cardinal (and not trivial) task. To fully and precisely characterize the performances of this detector physical events in the μ → eγ signal region are desired.
The production at rest of π0, in the charge exchange reaction π− + p → π0 + n, matches this requirement. Gammas from the π0 decay have an energy spectrum flat in the interval 54.9 < Eγ < 82.9 MeV and one can easily select a 54.9 MeV γ detecting a coincident γ emitted in the opposite direction. An auxiliary detector, facing the LXe calorimeter, is therefore required to select the higher energy γ while the other is used for calibration. The method illustrated allows establishing the energy, position and time resolutions of the LXe calorimeter.
A core component of these measurements is a target with the right properties and able to work in the presence of a high magnetic field. Here we present the liquid hydrogen target designed, built and used for this purpose during the first data-taking period of MEGII.
The challenge for new calorimetry for incoming experiments at intensity frontiers is to provide detectors with ultra-precise time resolution and supreme energy resolution.
Two very promising materials on the market are BrilLanCe (Cerium doped Lanthanum Bromide, LaBr3 (Ce)) and LYSO (Lutetium Yttrium OxyorthoSilicate, Lu2(1-x) Y2x SiO5 (Ce)), supported by recent developments aiming at providing new relative large crystals.
The response of both LaBr3 (Ce) and LYSO detectors having silicon photomultipliers as photosensors have been studied via detailed Monte Carlo (MC) simulations. The impinging gammas are in the range of 50-100 MeV. The MC simulations are based on GEANT4, including the full electronic chain up to the waveform digitization and finally the reconstruction algorithms.
For the (R = 4.45 cm, L = 20.3 cm) LaBr3 (Ce) crystal an energy resolution of σE /E ∼ 2.3(1)% and a timing resolution of σt ∼ 35(1) ps have been predicted. The energy resolution can be further improved by using larger crystals (either R = 6.35 cm or R = 7.6 cm, L = 20.3 cm) approaching respectively a σE/E ∼ 1.20(3)% or a σE /E ∼ 0.91(1)%.
Due to the shorter radiation length and smaller Moliere radius the LYSO crystal of the available size (R = 3.5 cm, L = 16 cm) performs better in terms of energy deposit compared to the currently available larger crystal made of LaBr3(Ce). An energy resolution of σE /E ∼ 1.48(4)% can be obtained, and that can be further improved using bigger crystals ( R = 6.5 cm, L = 25 cm, σE /E ∼ 0.74(1)% ). A σt ∼ 40(1) ps can be also achieved.
The size of the crystals considered here is optimal for assembling segmented big detectors as will be shown. Such results put these future high-energy calorimeters at the detector forefront at intensity frontiers.
SiPMs, Silicon Photo-Multipliers also referred to as Multi-Pixel Photon Counters (MPPCs), are solid state photo detectors, which consist of a high density matrix of avalanche photodiodes. Each photodiode operates in Geiger mode and works as photon-independent counter. They are characterized by an high internal gain which allows to detect from single photon to several thousand of photons. Furthermore their internal avalanche amplification is fast enough to obtain good timing properties. Due to their insensitivity to magnetic fields, low operating voltages, low cost and compactness, SiPMs have a wide range of applications in high energy physics instrumentation.
The present study aims to investigate the performance of a SiPM readout for application n calorimetry.
Hamamatsu MPPCs , with an effective photosensitive area of 3~\times~3~mm$^{2}$ and \lambda$_{MAX}~=~450~nm$, have been tested in two different configuration of 16 and 64 channels, for reading out a sampling calorimeter.
A dedicated experimental set-up has been realised using an electromagnetic calorimeter made of lead thin (0.5 mm) layers and scintillating fibres. The calorimeter is segmented in modules with a diameter of 4.3~cm; internal modules are read by conventional photo-multipliers tubes (PMTs) connecting to photo-guides at one ends. Similar photo-guides are used to connect tested SiPMs to the other end, coupling different configuration of guides.
Also the possibility of a directly SiPM read out, without light guides, is evaluated.
The SiPMs efficiency, time and space resolutions have been studied using secondary cosmic rays, with an external trigger provided by a system of scintillators.
Some preliminary results, compared to PMTs performance, will be presented.
The dual-readout calorimetric technique reconstructs the event-by-event electromagnetic fraction of hadronic shower through the simultaneous measurement of scintillating (S) and Cherenkov (C) light produced by the shower development. The new generation of prototypes, based on Silicon Photomultipliers (SiPMs) readout, is adding an unprecedented granularity to the well-known energy resolution.
A highly granular prototype (10x10x100mm3), designed to fully contain electromagnetic showers, has been recently built and qualified on beam. It consists of 9 modules, each made of 320 brass capillaries (OD = 2mm) equipped, alternatively, with scintillating and clear fibers. All the fibers of the central module are instrumented with SiPMs (one per capillary) while the PMTs are used for the others. The SiPM readout is based on the new FERS-System designed by Caen to fully exploit the CITIROC1A performances (i.e. wide dynamic range, linearity and multi-photon quality) even with SiPMs of small pitch size (15 μm) and small gain (1-3×105).
The recent test beam allowed to qualify the readout system and to define a procedure to calibrate the SiPM response from ADC to ph-e in a wide dynamic range: from 1 to 4000 ph-e (almost 60% of the cells available in the SiPM in use). In addition, this calibration provides the possibility to compensate for the intrinsic non-linear response of the sensor, when needed. The number of ph-e per GeV has been measured both for scintillating and Cherenkov light together with the calorimetric performances in the energy range of 10 – 100 GeV.
In this talk, I’ll review the system qualification, the test beam results, and the on-going R&D required to build a demonstrator capable to fully contain hadronic showers, required to assess the hadronic energy resolution.
CUPID is a proposed upgrade to the ton-scale neutrinoless double beta decay experiment, CUORE which is currently operating at the Laboratori Nazionali del Gran Sasso (LNGS). The primary background in CUORE are degraded $\alpha$'s, and CUPID aims to improve this background by over a factor of 100 via a two channel energy collection approach using scintillation light and heat. This will allow for event by event discrimination of $\alpha$ and $\gamma$/$\beta$ interactions. In order to meet the timing and energy resolution requirements of CUPID and beyond, large area light detectors which use low-Tc transition edge sensors (TES) deposited on Si wafers are a promising technology. Here we will present the current state of the ongoing collaboration with ANL to develop light detectors using an IrPt bilayer TES with Au pads to enhance thermal conductivity to the Si wafer. We report on the preliminary measures of timing and energy resolution, and possible differences in response due to position. Additionally we will discuss ongoing plans to explore multiplexed readout and other improvements.
Noise at the quantum limit over a large bandwidth is a fundamental requirement in forthcoming particle physics applications operating at low temperatures, such as neutrino measurements, x-ray observations, CMB measurements, and axion dark matter detection---involving MKIDs, TESs and microwave resonant cavity detectors---as well as in quantum technology applications, as the high-fidelity readout of qubits. The readout sensitivity of these detectors is currently limited by the noise temperature and bandwidth of available cryogenic amplifiers such as HEMTs or JPAs. The DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) project has the goal of developing high-performing innovative traveling wave parametric amplifiers with high gain, high saturation power, and nearly quantum-limited noise. The practical development follows two different promising approaches, one of which is based on Josephson junctions and is presented in this contribution: the Josephson Traveling Wave Parametric Amplifier (JTWPA).
Our JTWPA is designed as a coplanar waveguide embedded with a serial array of nonhysteretic single-junction cells of rf-SQUIDs, which allow to operate both in 3-wave-mixing and 4-wave-mixing mode. To avoid the presence of additional undesired tones besides the signal and idler, two layouts are currently being studied, the resonant phase matching and the quasi-phase matching.
A preliminary characterization was performed on a prototype JTWPA with 990 cells, in a dilution refrigerator with base temperature 15 mK. The operation in 3-wave-mixing was demonstrated, although with some nonhomogeneity issues, and a gain of about 25 dB was obtained.
The next step consists in improving the homogeneity of junctions: a sample of junctions with critical current $4~\mu\text{A}$ and self-capacitance 225 fF was fabricated. Their room-temperature normal resistances were tested with a probe-station, showing a good resistance spread between 5% and 10%.
Spectral information and imaging with photon wavelengths longer than 1.1 µm (equivalent to Si bandgap) become highly valued in astronomical applications. Thin-film-based image sensors are considered as one of the next-generation imaging platforms for this long-wavelength spectral range that cannot be covered by Si image sensors. Colloidal Quantum Dot (CQD)-based imagers are appealing due to their potential for scaling the pixel pitch and array size. Monolithic processing availability of the photodiode (PD) layer onto the Si Readout Integrated Circuit (ROIC) enables substantially scaling the pixel dimensions of CQD-based imagers compared to flip-chip integrated ones with bulk crystalline PDs made of III-V (InGaAs, InSb, ...) or II-VI semiconductor materials. In addition, the light absorption peak of CQD PD made from PbS can be tuned, covering the extended Short-Wave InfraRed (SWIR) wavelength region, which provides the capability for hyperspectral imaging and spectroscopy. In the sensors presented, the scalability is demonstrated by the pixel pitch down to sub-2 µm for our CQD SWIR imagers beneficial for better resolution, which enables diffraction-limited imaging with oversampling of the optical point spread function that can be used to correct aberrations and lessen requirements on optical system tolerances. Making a single CQD PD imager chip as large as the full wafer size becomes available with the help of full-wafer level processing capability. Thus, a sensor area up to 20,000 mm2, with a maximum 6 Gigapixel number is processible, assuming 200 mm Fab processing and minimum 1.82 µm pixel pitch. The external quantum efficiency (EQE) is shown to be 40% at its peak absorption wavelength of 1450 nm. We believe that this scalable SWIR imager equipped with the competitive EQE values can be applied to limited load satellites (e.g., CubeSat), as the high spatial and spectral resolution sensor enables on-the-fly reconfigurability extending the mission capacity of the satellites.
Large arrays of superconducting transition-edge sensor (TES) X-ray microcalorimeters are becoming the key technology for space and ground-based observatory in the field of astrophysics, laboratory astrophysics, particle-physics, plasma physics and material analysis. TES based X-ray detectors are non-dispersive spectrometers bringing together high-resolving power, imaging capability and high-quantum efficiency.
The TES X-ray calorimeters technology is entering a new era where arrays with more than 1000 pixels are routinely fabricated and cutting-edge instruments with dozen of multiplexing channels are being build for fundamental research at synchrotron and free electron laser facilities and plasma sources.
At SRON, we are developing the focal plane assembly and the back-up detector array for the the X-ray Integral Field Unit (X-IFU) on board of Athena. X-IFU will host an array of more than 3000 TES pixels with a $T_c\simeq 90\, \mathrm{mK}$, sensitive in the energy range of 0.2--12 $\mathrm{keV}$, with~an unprecedented energy resolution of 2.5~eV at 7 keV.
We have recently demonstrated the Frequency Division Multiplexing (FDM) read-out of 37 TiAu TES calorimeters with an exquisite energy resolution of 2.23 eV at 5.9 keV. Our FDM technology has proven to have low electrothermal cross-talk and to be relatively insensitive to external magnetic field, with respect to other multiplexing schemes.
We will discuss the prospects of using our cryogenic high-resolution X-ray imaging spectrometer based on TES detectors and FDM read-out as a diagnostic instrument for the existing and future fusion reactors. Moreover, our detectors could contribute in the study of atomic properties of high-Z metals, like tungsten and its many ionization stages.
We will finally show the challenges of developing and reading-out very large arrays of TES X-ray calorimeters with more than 10000 pixels for future astrophysics and fundamental research in particle physics, such as the detection of solar axions and the direct detection of the neutrino mass.
The electron electric dipole moment (e-EDM) is a model-independent probe of parity and time-reversal violation at energies beyond the ones that can be reached in particle colliders. The PHYDES project is an R&D experiment funded by CSN V of INFN aimed to test innovative approaches for e-EDM studies. In particular, the proposed idea is to use diatomic polar molecules, where e-EDM effects are amplified because of the large internal molecular field, embedded into cryogenic matrices made of unreactive elements. In such solids a diatomic molecule substitutes one the atom or molecule of the host matrix and, since the host-guest ratio can be 1:200, the density of the host molecules could be as large as $10^{22} $cm$^{−3}$.
The main goal of the PHYDES R&D program would be to try to embed Barium Fluoride (BaF) molecules in a solid matrix of para-Hydrogen (p-H2) and study their alignment with an external electric field and verify the assumption that BaF molecules are all polarized in p-H2 matrix.
The set-up we are developing to grow cryogenic crystal of around 1 cm$^3$ doped with about 100 ppm of BaF, consists of five different chambers. In the first one the BaF molecues are produced, ionized, accelerated and focused into the Wien Filter chamber which is necessary for mass selection. Then the molecular beam will be neutralized and cooled in order to prepare the BaF for the insertion in cryogenic crystal. In parallel we are developing an opportune system for para-Hydrogen production and storage. Finally the last chamber is the condensation chamber where a crystal of p-H2 doped with BaF can be grown through the matrix isolation technique.
Coherent elastic neutrino nucleus scattering (CEvNS) is a well-predicted Standard Model process only recently observed for the first time. Its precise study could reveal non-standard neutrino properties and open a window to search for physics beyond the Standard Model.
NUCLEUS is a CEvNS experiment conceived for the detection of neutrinos from nuclear reactors with unprecedented precision at recoil energies below 100 eV. Thanks to the large cross-section of CEvNS, an extremely sensitive cryogenic target of 10g of CaWO4 and Al2O3 crystals is sufficient to provide a detectable neutrino interaction rate.
NUCLEUS will be installed between the two 4.25 GW reactor cores of the Chooz-B nuclear power plant in the French Ardennes, which provide an anti-neutrino flux of 1.7 x 10^12 v/(s cm2). At present, the experiment is under construction. The commissioning of the full apparatus is scheduled for 2022, in preparation for the move to the reactor site.
This talk will present the concept and design of the experimental setup and go in detail on the sensitive detector technology enabling an advance of neutrino physics at the low-energy frontier.
Quantum sensing is a rapidly growing field of research which is already improving sensitivity in fundamental physics experiments. The ability to control quantum devices to measure physical quantities received a major boost from superconducting qubits and the improved capacity in engineering and fabricating this type of devices. Superconducting qubits have already been successfully applied in the detection of single photons via Quantum Non-Demolition (QND) measurements: this technique enables to perform multiple measurements of the same single photon improving sensitivity and reducing the dark counts rate. The goal of the Qub-IT project is to realize an itinerant single-photon counter exploiting QND measurements and entangled qubits, in order to surpass current devices in terms of efficiency and low dark-count rates. Such a detector has direct applications in Axion dark-matter experiments (such as QUAX), which require the photon to travel along a transmission line before being measured. For the Axion to interact, large magnetic fields are needed, therefore the superconducting device should be placed far from the interaction region.
In this contribution we present the design and simulation of the first superconducting device consisting of a transmon qubit coupled to a resonator which is being performed with Qiskit-Metal (IBM): this Python package provides a user-friendly toolkit for chip prototyping and simulation. Qiskit-Metal comes with different simulations to extract the circuit Hamiltonian parameters, such as resonant frequencies, anharmonicity and qubit-resonator couplings as well as an estimation for the qubit decay time ($T_{1}$). The Lumped Oscillator Model (LOM) and the Energy Participation Ratio (EPR) analyses exploit Ansys Q3D and Ansys HFSS to perform electromagnetic simulations, before calculating the Hamiltonian of the circuit.
The simulation phase is fundamental in order to tune each parameter of the chip design to obtain the desired Hamiltonian before moving to the manufacturing stage.
To achieve the extreme sensitivities necessary to perform elusive particle searches like $\beta$-decay spectroscopy for neutrino mass measurement or dark matter detection, future experiments will employ large arrays of cryogenic detectors, such as metallic-magnetic calorimeters or transition-edge sensors (TES).
A TES is a thin film of superconducting material weakly coupled to a thermal bath typically at $T < 100$ mK, that can be used as a radiation detector by exploiting its very sharp phase transition. We have been developing X-ray TES micro-calorimeters optimized for X-ray astronomy up to energies of 12 keV, as well as a frequency-domain multiplexing (FDM) technology to perform their readout. Energies up to $\sim$10 keV are compatible with the expected spectrum of axion-like particles arriving on Earth generated in the Sun by electron processes and Primakoff conversion, which will be investigated in the future by axion helioscopes. A fundamental instrumental requirement is the background of the X-ray detectors, which should be at a level of $10^{-7}$ keV$^{-1}$cm$^{-2}$s$^{-1}$. TES represent a suitable choice for this science case, given their high energy resolution and quantum efficiency, low intrinsic background and scalability to large ($\sim 1000$s) arrays.
In this contribution we present a measurement of the X-ray detectors background, using a TES array with $240\times240\ \mu \text{m}^2$ absorber area and energy resolution at a level of 2 eV at 5.9 keV with an FDM readout. With an effective integration time of 40 days, we measured a background rate at a level of $10^{-3}$ keV$^{-1}$cm$^{-2}$s$^{-1}$ in the energy range of 1 to 10 keV.
We show the data analysis method and prospect possible improvements, such as coupling with a cryogenic anti-coincidence and the introduction of a PTFE and Cu shielding around the sensitive area of the setup, to further reduce the background rate.
The 50 mK cryogenic focal plane anti-coincidence detector of the Athena X-ray observatory (CryoAC) is a silicon suspended absorber sensed by a network of 400 Ir/Au Transition Edge Sensors (TES) and connected through silicon bridges to a surrounding silicon frame plated with gold (RIM). The device is shaped by Deep Reactive Ion Etching (DRIE) from a single silicon wafer of 500 um. There are two different possible geometries: A single Monolithic absorber and a Segmented one with 4 distinct absorber structure. As part of the payload of space a mission the detector must resist to several mechanical excitations. We have tested a set of prototypes of the CryoAC vibrating several hexagonal Silicon samples. This vibrating them using the vibrational mask provided by CNES for the future ARIANE 6. The aim is to have a first information on the mechanical response of the Silicon bridges that connect the absorber to the RIM, to start a tradeoff over the two geometries and to validate the elastic-mechanical response.
Future experiments pursuing scientific breakthroughs in the fields of astronomy, cosmology or astro-particle physics will take advantage of the extreme sensitivities of cryogenic detectors, such as transition-edge sensors (TES).
A TES is a thin film of superconducting material weakly coupled to a thermal bath typically at $T < 100$~mK, used as a radiation detector by exploiting its sharp phase transition, providing unprecedented resolving power and imaging capabilities. We have been developing TES micro-calorimeters for X-ray spectroscopy for the Athena X-ray Integral Field Unit (X-IFU), demonstrating under AC bias resolving power capabilities of $E/\Delta E \simeq 3000$.
Performing the readout of thousands of detectors operating at sub-K temperatures represents an instrumental challenge. We have been developing, in the framework of X-IFU, a frequency-domain multiplexing (FDM) technology, where each TES is coupled to a superconducting band-pass LC resonator and AC biased at MHz frequencies through a common readout line. The TES signals are summed at the input of a superconducting quantum interference device (SQUID), performing a first amplification at cryogenic stage. A custom analog front-end electronics further amplifies the signals at room temperature. A custom digital board handles the digitization and modulation/demodulation of the TES signals and bias carriers.
Using Ti/Au TES micro-calorimeters, high-Q LC filters and analog/digital electronics developed at SRON and low-noise two-stage SQUID amplifiers from VTT Finland, we demonstrated using two experimental setups the feasibility of our FDM readout technology, with the simultaneous readout of 31 pixels with an energy resolution of 2.14 eV and 37 pixels with an energy resolution at of 2.23 eV, exploiting 5.9 keV photons from an $^{55}$Fe source.
We report the technological challenges of the FDM development and their solutions, already implemented or envisaged to further improve the matureness of this technology, as well as prospects for further scaling up and future possible applications.
The current technology of thermal detectors for rare events physics is based on large cryogenic calorimeters read with NTD thermistors. Measuring the total energy deposition via the heat release in the crystal lattice allows for optimal energy resolutions when the detectors are operated at 10mK. In case the crystals are made of a scintillating material, a double readout of heat and scintillation light could allow for an improved discrimination between alpha and beta/gamma events.
Cryogenic detectors read with NTD are generally characterised by a slow time response, limited by the several thermal factors playing a role in the signal formation. For example, the traditional glue coupling between the NTD and the absorber could introduce spurious and variable thermalisation time constants to the signal. A new technique for coupling the NTD to the absorber crystal would be the silicate bonding, applied already in several fields of satellite and optical physics. We will be showing the first results of NTD coupled on LMO crystal with the silicate bonding technique, when these are operated as cryogenic calorimeters at 10 mK.
A second fundamental aspect for these detectors is the improvement in the collection of scintillation light. In general, the light detectors are Ge or Si wafers, operated also as thermal detectors, absorbing the scintillation photons and converting them into heat. We are now proposing to use instead a plastic film with high absorbance for optical photons, wrapped around the scintillating calorimeter. In particular, we will be showing the results obtained with a thermal light detector made in KAPTON® film, operated in the Milano Cryogenic Lab.
We have developed a SQUID controller unit for TES sensors readout, designed to be used in a space mission. The unit is made of 8 boards and each board can condition four SQUID array amplifiers. The board design is inspired by a similar one developed for ground based experiments, but specific changes have been made to adopt COTS with space grade equivalents, to implement redundancy and cross-strapping capabilities. The design also includes the thermal path to lift the heat off the boards towards an in-house designed monolithic aluminum rack. In this contribution we report the board performances in terms of cross-talk, bandwidth and noise, together with the thermo-mechanical simulations.
Nowadays, many experiments with very high energy resolution detectors rely on the faithful detection of low power microwave signals at cryogenic temperatures. This is especially true also in the field of the superconducting quantum computation, where quantum-limited noise microwave amplification is paramount to infer the qubit state with high fidelity.
For these applications, the goals are to maximize the signal to noise ratio of microwave signals extremely feeble while allowing a broad readout bandwidth.
The latter is also important, because both the quantum and the particle physics fields require to readout very large arrays of qubit and Low Temperature Detectors to achieve meaningful results in terms of computational power and acquired statistics respectively. To solve this problem, parametric amplification, a well known technique used for low noise amplifiers, will be exploited and developed to its technical limits.
DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) is a three years project that aims to develop high-performing innovative traveling wave parametric amplifiers (TWPAs). The practical development follows two different promising approaches, one based on the Josephson junctions (TWJPA) and the other one based on the kinetic inductance of a high-resistivity superconductor (KITWPA). The technical goal is to achieve a gain value around 20 dB, comparable to the currently used semiconductors low temperature amplifiers (HEMT), with a high saturation power (around -50 dBm), and a quantum limited or nearly quantum limited noise ($T_N<$ 600 mK). These features will lead to the readout of large arrays of detectors or qubits with no noise degradation. In particular, this contribution will present the progress made so far in the design and development of a KITWPA as a weakly dispersive artificial transmission line by the DARTWARS collaboration.
BULLKID (Bulky and low-threshold kinetic inductance detectors) is an R&D project on an innovative cryogenic particle detector to search for low-energy nuclear recoils induced by neutrino coherent scattering or Dark Matter interactions. The detector unit consists of an array of 60 silicon absorbers of 0.3 g each sensed by phonon-mediated, microwave-multiplexed Kinetic Inductance Detectors. The arrays built up to now feature a total active mass of 20 g and the technology is engineered to ensure an easy scalability to a future kg-scale experiment. In this talk we will describe BULLKID and we will present the recent and encouraging results obtained from the operation of the first prototypes.
Advances in superconducting detector arrays are driving progress in the field of cosmic microwave background (CMB) measurements. In the last decade ground-based CMB projects have employed arrays of thousands of superconducting transition-edge sensors (TESes) to make great progress in cosmological constraints from early universe inflation to the Hubble expansion rate. These arrays are operated at sub-Kelvin temperatures and utilize superconducting quantum interference device (SQUID) amplifiers to multiplex and amplify the TES signals before they are digitized. Kinetic inductance detectors (KIDs) are a newer superconducting detector technology that are naturally multiplexed in frequency and have been deployed at smaller scales with promising results. We review the development of arrays of TESes and KIDs, then describe the progress being made in scaling these technologies towards tens of thousands and hundreds of thousands of detectors for the upcoming Simons Observatory, CCAT-prime, and CMB-S4 projects.
The next 10 years will be exciting for High Energy Physics, with new experiments entering data taking (High Luminosity LHC) or being designed and eventually approved (FCC, CEPC, ILC, MU_COLL). In all the cases, the computing infrastructures, including the software stacks for selection, simulation, reconstruction and analyses, will be crucial for the success of the physics programs. Many directions are being explored by the community, like heterogeneous computing for the most time-critical tasks, and AI inspired techniques to squeeze the ultimate performance and in order to match reasonable resource budgets.
The contribution wants to address the landscape and the state-of-the-art in the field, highlighting the strong and weak points, and the aspects which still need sizeable R&D.
After a concise description of the bolometric technique, including hybrid devices with double readout, the advantages of this technology for rare event searches are highlighted and discussed. Special methods for the reduction of different forms of background are overviewed. Three
examples of bolometric double-beta decay experiments, spanning a wide range of background rejection techniques, are examined in detail: CUPID-Mo, CROSS and BINGO.
The nSOL experiment to operate a neutrino detector close to the Sun is building a small test detector to orbit the Earth to test the concept in space. This detector concept has to provide a new way to detect neutrinos unshielded in space. A double delayed coincidence on Gallium nuclei that have a large cross section for solar neutrino interactions convert it into an excited state of Germanium,which decays with a well-known energy and half-life. This unique signature permits operation of the detector volume mostly unshielded in space with a high single particle counting rate of gamma and cosmic ray events. The test detector concept which has been studied in the lab and is planned for a year of operations orbiting Earth which is scheduled for launch in late 2024. It will surrounded by an active veto and shielding will be operated in a polar orbit around the Earth to validate the detector concept and study detailed background spectrums that can fake the timing and energy signature from random galactic cosmic or gamma rays. The success of this new technology development will permit the design of a larger spacecraft with a mission to fly close to the Sun and is of importance to the primary science mission of the Heliophysics division of NASA Space Science Mission Directorate, which is to better understand the Sun by measuring details of our Sun's fusion core.
Serendipitously discovered by the BATSE mission in the nineties, Terrestrial Gamma-ray Flashes (TGFs) represent the most intense and energetic natural emission of gamma rays form our planet. TGFs consist of sub-millisecond bursts of gamma rays (energy up to one hundred MeV) generated during powerful thunderstorms by lightenings (average ignition altitude of about 10 km) and are in general companions of several other counterparts (electron beams, neutrons, radio waves). The ideal observatory for TGF is therefore a fast detector, possibly with spectral abilities and orbiting around Earth in LEO (Low Earth Orbit). To date, the benchmark observatory is ASIM, an instrument flying onboard the International Space Station (ISS). LIGHT-1 is a 3U Cubesat mission launched in December 21st, 2021 and deployed from the ISS on February 3rd, 2022. The LIGHT-1 payload consists of two similar instruments conceived to effectively detect TGF at few hundred nanoseconds timescale. The detection unit is composed of a scintillating crystal organised in four optically independent channels, read out by as many photosensors. The detection unit is surrounded by a segmented plastic scintillator layer that acts as an anti coincidence VETO for charged particles. The customised electronics consists of three different boards embedding the power supplies and detector readout, signal processing, detector controls and interface with the bus of the spacecraft. LIGHT-1 makes the use of two different scintillating crystals, namely (low background) Cerium Bromide ($\mathrm{CeBr_3}$) and Lanthanum Bromo Chloride (LBC), and two different photo sensing technologies based on PhotoMultiplier Tubes (R11265-200 manufactured by Hamamatsu) and Silicon Photomultipliers (ASD-NUV1C-P manufactured by Advansid and S13361-6050AE-04 manufactured by Hamamatsu). Payload performance and detailed description will be provided, along with simulation and pre-flight diagnostic tests and calibration. The first release of in orbit Science Data will be also presented.
Only a few years after the first direct detections by LIGO and Virgo, the gravitational-wave (GW) field is at a turning point, with a rapidly increasing number of confirmed signals – all from compact binary mergers so far. This dataset offers a wealth of information and allows scientists to study the populations of compact objects and the rates at which they merge, permitting tests of general relativity in a strong regime that had not been probed previously. This progress is made possible by the improvements in terms of sensitivity and duty cycle of the second-generation ground-based GW detectors, such as by advances in the analysis of the recorded data.
Key to this dataflow are the detector characterization and data quality activities, collectively referred to as “DetChar” in the following. The former help improve knowledge of the instruments while fighting against their dominant noise sources (transient or continuous), while the latter shape the dataset for the analysts, vet the GW candidates found either in low latency or offline, and contribute to mitigating the effect of noise when inferring the GW source properties from the detected signals.
With this joint abstract, the LIGO and Virgo DetChar groups present their main contributions to the GW detection effort during the third Observing Run (O3, April 2019 – March 2020). After that summary, we describe the main developments and improvements that are in progress to cope with the increase in detection rate expected for the fourth LIGO-Virgo-KAGRA Observing Run (O4), currently planned to start at the end of the year. The goals are manifold: to extend the data quality coverage, to decrease the latency of the main DetChar products and to automate as much as possible the different analysis – both their processing and their reporting.
We present the latest results on the development of the Dark-PMT, a novel light Dark Matter (