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Showing papers in "Journal of Instrumentation in 2023"


DOI
TL;DR: In this article , the authors examined the response of the pixel detector Timepix3 with silicon sensor to well-defined fast neutrons fields and identified and classified the neutron-induced tracks in terms of the broad-type particle-event track classes.
Abstract: We examined the response of the pixel detector Timepix3 with silicon sensor to well-defined fast neutron fields. Part of the pixel detector silicon sensor was additionally equipped with a neutron mask of distinct converter regions. The mask consists of separate thermal and fast neutron regions using 6LiF and hydrogen (plastic) converters, respectively. Measurements were performed with mono-energetic fast neutrons produced at D-D and D-T sources from a Van de Graaff accelerator and a neutron generator, respectively. Data were collected with low background including measurements with moderator material to provide a thermalized neutron component. All the signals produced in the detector were analyzed and decomposed in terms of the spectral-tracking response of the pixel detector. The effect of the fast and thermal components of the neutron converter were determined and compared with direct interactions in the silicon sensor which are significant and can be dominant for fast neutrons. We identify and classify the neutron-induced tracks in terms of the broad-type particle-event track classes. A partial overlap is unavoidable with tracks from direct detection of other radiations in particular protons and low-energy light ions as well as X rays. This will limit the neutron-event discrimination in mixed-radiation fields. The detection response according sensor-mask region was examined and calibrated for the investigated neutron fields. The neutron detection efficiency is selectively derived for the detector particle-event classes. This approach enables to enhance the neutron-discrimination and suppress background and unwanted events. This work enables to extend the response matrix of the detector for broad-type radiations to include neutrons both fast and thermal. The results serve to enhance the sensitivity and determine the neutron component in unknown and mixed-radiation fields such as outer space and particle radiotherapy environments.

3 citations


DOI
TL;DR: In this paper , the ATLAS Inner Detector was replaced by an all-silicon tracker (ITk) consisting of two systems: pixels and strips, which were tested against single event effects due to radiation.
Abstract: For the high-luminosity upgrade to the LHC, the ATLAS Inner Detector will be replaced by an all-silicon tracker (ITk) consisting of two systems: pixels and strips. HCC and AMAC are ITk Strip ASICs vital for performing the system readout, monitoring, and control. To ensure these ASICs will successfully operate in the high-radiation environment of the HL-LHC, they need to be tested for radiation tolerance, and tests have been performed using both heavy ions and protons. The ASIC designs were shown to protect against single event effects due to radiation.

3 citations


Journal ArticleDOI
TL;DR: In this paper , a TMR protection scheme is applied to protect a RISC-V microprocessor core against these faults and the protection of the integrated SRAM by an independent scrubbing algorithm is discussed.
Abstract: While microprocessors are used in various applications, they are precluded from the use in high-energy physics applications due to the harsh radiation present. To overcome this limitation a microprocessor design must withstand high doses of radiation and mitigate radiation induced soft errors. A TMR protection scheme is applied to protect a RISC-V microprocessor core against these faults. The protection of the integrated SRAM by an independent scrubbing algorithm is discussed. Initial irradiation results and power consumption measurements of the radiation-resistant RISC-V microprocessor implemented in 65 nm CMOS technology are presented.

3 citations


Journal ArticleDOI
TL;DR: In this article , three radiation-tolerant ASICs (HCC, AMAC, and ABC) were used to verify the performance of the ITk Strip charged-particle tracker for the ATLAS detector at the HL-LHC.
Abstract: Abstract The verification of ASICs through simulation is critical to ensure their successful operation in particle physics detectors and to minimize the number of long and expensive production cycles required. Three radiation-tolerant ASICs (HCC, AMAC, and ABC) will perform the front-end readout, monitoring, and control of the ITk Strip charged-particle tracker for the ATLAS detector at the HL-LHC. The Python-based cocotb verification framework is used to design sophisticated tests with contributions from ASIC verification non-experts and students. The verification program includes interactions between multiple ASICs, realistic data flows, operational stress tests, and a focus on mitigation of disruptive Single Event Effects due to radiation.

3 citations


DOI
TL;DR: In this article , the authors explored the combination of the TR30 cyclotrons' age and the challenges of maintaining their performances, and the subsystems' failures and their part in the overall downtime.
Abstract: Negative ions compact cyclotrons serve many applications and are known to be effective due to their simple and efficient extraction as well as the large circulating currents without the requirement of separated turns. TR30s are compact cyclotrons that have continued to experience impressive technological advances over the last few decades, driven primarily by medical isotope production needs. Their space charge limits are in the range of 1 to 2 mA, and we explored the combination of our machines' age and the challenges of maintaining their performances. Certain subsystems are detailed with specific examples from more than 30 years of around-the-clock, quasi continuous operations with TR30 cyclotrons. The subsystems' failures and their part in the overall downtime will be presented.

3 citations


Peer ReviewDOI
TL;DR: The ATLAS experiment is constructing new all-silicon inner tracking system for HL-LHC as mentioned in this paper , which uses p-type silicon material, making the readout in n+-strips, so-called n+in-p sensors.
Abstract: The ATLAS experiment is constructing new all-silicon inner tracking system for HL-LHC. The strip detectors cover the radial extent of 40 to 100 cm. A new approach is adopted to use p-type silicon material, making the readout in n+-strips, so-called n+-in-p sensors. This allows for enhanced radiation tolerance against an order of magnitude higher particle fluence compared to the LHC. To cope with varying hit rates and occupancies as a function of radial distance, there are two barrel sensor types, the short strips (SS) for the inner 2 and the long strips (LS) for the outer 2 barrel cylinders, respectively. The barrel sensors exhibit a square, 9.8 × 9.8 cm2, geometry, the largest possible sensor area from a 6-inch wafer. The strips are laid out in parallel with a strip pitch of 75.5 μm and 4 or 2 rows of strip segments. The strips are AC-coupled and biased via polysilicon resistors. The endcap sensors employ a “stereo-annulus” geometry exhibiting a skewed-trapezoid shapes with circular edges. They are designed in 6 unique shapes, R0 to R5, corresponding to progressively increasing radial extents and which allows them to fit within the petal geometry and the 6-inch wafer maximally. The strips are in fan-out geometry with an in-built rotation angle, with a mean pitch of approximately 75 μm and 4 or 2 rows of strip segments. The eight sensor types are labeled as ATLAS18xx where xx stands for SS, LS, and R0 to R5. According to the mechanical and electrical specifications, CAD files for wafer processing were laid out, following the successful designs of prototype barrel and endcap sensors, together with a number of optimizations. A pre-production was carried out prior to the full production of the wafers. The quality of the sensors is reviewed and judged excellent through the test results carried out by vendor. These sensors are used for establishing acceptance procedures and to evaluate their performance in the ATLAS collaboration, and subsequently for pre-production of strip modules and stave and petal structures.

3 citations


DOI
TL;DR: In this paper , a 2 GeV continuous wave isochronous accelerator with 3 mA beam intensity design is presented, where the radial gradient of the average magnetic field makes the field distribution match the isocronism.
Abstract: The MW class proton accelerators are expected to play important roles in many fields, attracting institutions to continue researching and tackling key problems. The continuous wave (CW) isochronous accelerator obtains a high-power beam with higher energy efficiency, which is very attractive to many applications. Scholars generally believe that the energy limitation of the isochronous cyclotron is ∼1 GeV. To get higher beam power by the isochronous machine, enhancing the beam focusing become the most important issue. Adjusting the radial gradient of the average magnetic field makes the field distribution match the isochronism. When we adjust the radial gradient of the peak field, the first-order gradient is equivalent to the quadrupole field, the second-order, the hexapole field, and so on. Just like the synchrotron, there are quadrupoles, hexapole magnets, and so on, along the orbits to get higher energy, as all we know. If we adjust the radial gradient for the peak field of an FFA's FDF lattice and cooperate with the angular width (azimuth flutter) and spiral angle (edge focusing) of the traditional cyclotron pole, we can manipulate the working path in the tune diagram very flexibly. During enhancing the axial focusing, both the beam intensity and the energy of the isochronous accelerator are significantly increased. Here a 2 GeV CW FFA with 3 mA of average beam intensity design is presented. It is essentially an isochronous cyclotron although we use 10 FDF lattices. The key difficulty is that the magnetic field and each order of gradient should be accurately adjusted in a large radius range. As a high-power proton accelerator with high energy efficiency, we adopt high-temperature superconducting (HTS) technology for the magnets. 15 RF cavities with a Q value of 90000 provide energy gain per turn of ∼15 MeV to ensure the CW beam intensity reaches 3 mA. A 1:4 scale, 15-ton HTS magnet, and a 1:4 scale, 177 MHz cavity have been completed. The results of such R&D will also be presented in this paper.

3 citations


Journal ArticleDOI
TL;DR: An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers equipped with 16 bolometric Ge light detectors, aiming at optimization of detector structure for CROSS and CUPID double-beta decay experiments, was constructed and tested in a low-background pulse-tube-based cryostat at the Canfranc underground laboratory in Spain this paper .
Abstract: An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers equipped with 16 bolometric Ge light detectors, aiming at optimization of detector structure for CROSS and CUPID double-beta decay experiments, was constructed and tested in a low-background pulse-tube-based cryostat at the Canfranc underground laboratory in Spain. Performance of the scintillating bolometers was studied depending on the size of phonon NTD-Ge sensors glued to both LMO and Ge absorbers, shape of the Ge light detectors (circular vs. square, from two suppliers), in different light collection conditions (with and without reflector, with aluminum coated LMO crystal surface). The scintillating bolometer array was operated over 8 months in the low-background conditions that allowed to probe a very low, μBq/kg, level of the LMO crystals radioactive contamination by 228Th and 226Ra.

3 citations


Journal ArticleDOI
TL;DR: In this article , a thin resistive DLC layer deposited on top of an insulator is inserted in between the electron multiplier (THGEM) and the readout anode, and a resistive ferrite plate is directly coupled to the THGEM.
Abstract: Cryogenic versions of Resistive WELL (RWELL) and Resistive Plate WELL (RPWELL) detectors have been developed, aimed at stable avalanche multiplication of ionization electrons in the vapor phase of LAr (dual-phase TPC). In the RWELL, a thin resistive DLC layer deposited on top of an insulator is inserted in between the electron multiplier (THGEM) and the readout anode; in the RPWELL, a resistive ferrite plate is directly coupled to the THGEM. Radiation-induced ionization electrons in the liquid are extracted into the gaseous phase. They drift into the THGEM's holes where they undergo charge multiplication. Embedding resistive materials into the multiplier proved to enhance operation stability due to the mitigation of electrical discharges — thus allowing operation at higher charge gain compared to standard THGEM (a.k.a. LEM) multipliers. We present the detector concepts and report on the main preliminary results.

2 citations


DOI
TL;DR: In this paper , the authors used the SCALA-solver of Opera3D to find the ion source plasma meniscus and the beam phase space and current extracted from it, with these properties known, they studied the bunch formation and acceleration under high space charge condition with their in-house tracking code AOC.
Abstract: At IBA a high-intensity compact self-extracting cyclotron is being studied. There is no dedicated extraction device but instead, a special shaping of the magnetic iron and the use of harmonic coils to create large turn-separation. Proton currents up to 5 mA are aimed for. This would open new ways for large-scale production of medical radioisotopes. The main features of the cyclotron are presented. A major variable of the beam simulations is the space charge effect in the cyclotron centre. Using the SCALA-solver of Opera3D, we attempt to find the ion source plasma meniscus and the beam phase space and current extracted from it. With these properties known, we study the bunch formation and acceleration under high space charge condition with our in-house tracking code AOC. We also discuss a new tool that automates optimization of cyclotron settings for maximizing beam properties such as extraction efficiency.

2 citations


Journal ArticleDOI
TL;DR: In this paper , the authors examined the response of the pixel detector Timepix3 with silicon sensor to well-defined fast neutrons fields and identified and classified the neutron-induced tracks in terms of the broad-type particle-event track classes.
Abstract: Abstract We examined the response of the pixel detector Timepix3 with silicon sensor to well-defined fast neutron fields. Part of the pixel detector silicon sensor was additionally equipped with a neutron mask of distinct converter regions. The mask consists of separate thermal and fast neutron regions using 6 LiF and hydrogen (plastic) converters, respectively. Measurements were performed with mono-energetic fast neutrons produced at D-D and D-T sources from a Van de Graaff accelerator and a neutron generator, respectively. Data were collected with low background including measurements with moderator material to provide a thermalized neutron component. All the signals produced in the detector were analyzed and decomposed in terms of the spectral-tracking response of the pixel detector. The effect of the fast and thermal components of the neutron converter were determined and compared with direct interactions in the silicon sensor which are significant and can be dominant for fast neutrons. We identify and classify the neutron-induced tracks in terms of the broad-type particle-event track classes. A partial overlap is unavoidable with tracks from direct detection of other radiations in particular protons and low-energy light ions as well as X rays. This will limit the neutron-event discrimination in mixed-radiation fields. The detection response according sensor-mask region was examined and calibrated for the investigated neutron fields. The neutron detection efficiency is selectively derived for the detector particle-event classes. This approach enables to enhance the neutron-discrimination and suppress background and unwanted events. This work enables to extend the response matrix of the detector for broad-type radiations to include neutrons both fast and thermal. The results serve to enhance the sensitivity and determine the neutron component in unknown and mixed-radiation fields such as outer space and particle radiotherapy environments.

DOI
TL;DR: In this paper , a silicon photomultiplier (SiPM) with a deep pixel structure was used in nuclear gamma spectrometry, which will make it possible to increase the efficiency of scintillation detectors.
Abstract: The development of nuclear technologies, the production and active use of radioisotopes, and the production of radiopharmaceuticals, medical isotopes and other radioactive materials are increasing every year. Therefore, the importance of ensuring the safety of highly active isotopes, as well as providing the necessary instruments for measuring and identifying radioactive materials, must be taken into account. Modern equipment such as high purity germanium detectors (HPGe) is costly and requires specialized staff skills as well as special operating conditions such as low temperatures and high voltages. It is proposed to explore the possibilities of using a silicon photomultiplier (SiPM) with a deep pixel structure in nuclear gamma spectrometry, which will make it possible to increase the efficiency of scintillation detectors. The paper presents the results of a study of the newest silicon photomultipliers MAPD-3NM II assembled in a 16-element matrix, which was the detector part of the proposed LaBr3(Ce) scintillation spectrometer. The study was carried out using radioisotopes of uranium. The aim of the research is to reveal the possibility of differentiating depleted and natural uranium materials from each other without using special software by means of the proposed set of equipment.

DOI
TL;DR: Hybrid Controller Chip (HCC) as mentioned in this paper is one of three new radiation-tolerant ASICs for the silicon-strip detector for ATLAS, which is responsible for buffering and forwarding control signals and readout requests to multiple binary readout ASICs as well as serializing their readout data into a 640 Mbps output.
Abstract: The high-luminosity upgrade to the LHC requires a new silicon-strip charged-particle tracking detector for ATLAS. The HCC (Hybrid Controller Chip) is one of three new radiation-tolerant ASICs for this silicon-strip detector. As the interface to multiple binary readout ASICs, the HCC is responsible for buffering and forwarding control signals and readout requests to them as well as serializing their readout data into a 640 Mbps output. All HCCs undergo a suite of tests to verify their analog and digital functionality. The yield for the HCC exceeds the 90% target for production.

DOI
TL;DR: The AMACStar chip is one of three radiation hard ASICs that will be installed on the ITk Strip subdetector modules as discussed by the authors , which operates autonomously and its function is to monitor and control the temperatures, voltages, and currents in the module components, preventing these quantities from reaching dangerous levels.
Abstract: The ATLAS detector requires an all new inner detector, the Inner Tracker (ITk), due to the high-luminosity upgrade to the LHC (HL-LHC). The AMACStar chip is one of three radiation hard ASICs that will be installed on the ITk Strip subdetector modules. The ASIC operates autonomously and its function is to monitor and control the temperatures, voltages, and currents in the module components, preventing these quantities from reaching dangerous levels. A total of 18000 AMACStars are needed for the ITk Strip subsystem. Wafers of these chips are probed at the University of Pennsylvania. Comprehensive probe-station testing software and procedures have been developed in order to verify the digital and analog functionality of every AMACStar. A detailed grading scheme is applied to determine which chips should be installed on the modules. The results from probing the first 11 wafers with the final design satisfy the required 90% yield needed for production goals. Probing of production AMACStar wafers began in December 2022 and will continue throughout 2023.

DOI
TL;DR: In this paper , three radiation-tolerant ASICs (HCC, AMAC, and ABC) were used to verify the performance of the ITk Strip charged-particle tracker for the ATLAS detector at the HL-LHC.
Abstract: The verification of ASICs through simulation is critical to ensure their successful operation in particle physics detectors and to minimize the number of long and expensive production cycles required. Three radiation-tolerant ASICs (HCC, AMAC, and ABC) will perform the front-end readout, monitoring, and control of the ITk Strip charged-particle tracker for the ATLAS detector at the HL-LHC. The Python-based cocotb verification framework is used to design sophisticated tests with contributions from ASIC verification non-experts and students. The verification program includes interactions between multiple ASICs, realistic data flows, operational stress tests, and a focus on mitigation of disruptive Single Event Effects due to radiation.

Journal ArticleDOI
TL;DR: The New Experiments With Spheres-Gas (NEWS-G) collaboration as mentioned in this paper has achieved WIMP detection using Spherical Proportional Counters (SPCs) with a single ionization electron energy threshold.
Abstract: The New Experiments With Spheres-Gas (NEWS-G) collaboration intends to achieve $\mathrm{sub-GeV/c^{2}}$ Weakly Interacting Massive Particles (WIMPs) detection using Spherical Proportional Counters (SPCs). SPCs are gaseous detectors relying on ionization with a single ionization electron energy threshold. The latest generation of SPC for direct dark matter searches has been installed at SNOLAB in Canada in 2021. This article details the different processes involved in the fabrication of the NEWS-G experiment. Also outlined in this paper are the mitigation strategies, measurements of radioactivity of the different components, and estimations of induced background event rates that were used to quantify and address detector backgrounds.

DOI
TL;DR: In this article , ion temperature and toroidal rotation measurements performed on ST40 during the 2021-22 campaign for a range of different scenarios are used, analysing their correlation and interpreting their differences using new diagnostic forward models.
Abstract: ST40 is a high field low-aspect ratio spherical tokamak built and operated by Tokamak Energy Ltd. Recent plasma operations were aimed at exploring operational scenarios to maximise the central plasma temperature and have culminated in the achievement of thermal ion temperatures of over 9 keV. This paper presents ion temperature and toroidal rotation measurements performed on ST40 during the 2021–22 campaign for a range of different scenarios. Several independent diagnostic systems are used, analysing their correlation and interpreting their differences using new diagnostic forward models.

Journal ArticleDOI
TL;DR: In this paper , two snapshots of the delay line are taken by the register array with two strobes separated with a known time interval, and the two snapshots can be averaged to improve the TDC measurement precision.
Abstract: Abstract The time-to-digital-converter (TDC) using uncontrolled delay lines has a simple structure and finer measurement precision since the delay cells are pure digital gates that operate at maximum speed. For every incoming hit, two “snapshots” of the delay line are taken by the register array with two strobes separated with a known time interval. With two measurements, propagation delays of each cell in the delay line can be calibrated for the operating temperature and voltage. The two measurements can also be averaged to improve the TDC measurement precision. We will discuss various calibration approaches and present test results in this work.

Journal ArticleDOI
TL;DR: In this article , the authors presented the results obtained with data recorded by an oscilloscope synchronized with a beam telescope, which provides particle position information within a few μm, collected charge, time resolution and hit efficiency measurements are presented.
Abstract: The High Granularity Timing Detector (HGTD) will be installed in the ATLAS experiment to mitigate pile-up effects during the High Luminosity (HL) phase of the Large Hadron Collider (LHC) at CERN. Low Gain Avalanche Detectors (LGADs) will provide high-precision measurements of the time of arrival of particles at the HGTD, improving the particle-vertex assignment. To cope with the high-radiation environment, LGADs have been optimized by adding carbon in the gain layer, thus reducing the acceptor removal rate after irradiation. Performances of several carbon-enriched LGAD sensors from different vendors, and irradiated with high fluences of 1.5 and 2.5 × 1015 neq/cm2, have been measured in beam test campaigns during the years 2021 and 2022 at CERN SPS and DESY. This paper presents the results obtained with data recorded by an oscilloscope synchronized with a beam telescope which provides particle position information within a resolution of a few μm. Collected charge, time resolution and hit efficiency measurements are presented. In addition, the efficiency uniformity is also studied as a function of the position of the incident particle inside the sensor pad.

Journal ArticleDOI
TL;DR: In this article , a silicon photomultiplier (SiPM) with a deep pixel structure was used in nuclear gamma spectrometry, which will make it possible to increase the efficiency of scintillation detectors.
Abstract: Abstract The development of nuclear technologies, the production and active use of radioisotopes, and the production of radiopharmaceuticals, medical isotopes and other radioactive materials are increasing every year. Therefore, the importance of ensuring the safety of highly active isotopes, as well as providing the necessary instruments for measuring and identifying radioactive materials, must be taken into account. Modern equipment such as high purity germanium detectors (HPGe) is costly and requires specialized staff skills as well as special operating conditions such as low temperatures and high voltages. It is proposed to explore the possibilities of using a silicon photomultiplier (SiPM) with a deep pixel structure in nuclear gamma spectrometry, which will make it possible to increase the efficiency of scintillation detectors. The paper presents the results of a study of the newest silicon photomultipliers MAPD-3NM II assembled in a 16-element matrix, which was the detector part of the proposed LaBr 3 (Ce) scintillation spectrometer. The study was carried out using radioisotopes of uranium. The aim of the research is to reveal the possibility of differentiating depleted and natural uranium materials from each other without using special software by means of the proposed set of equipment.

Journal ArticleDOI
TL;DR: The Versatile Link + project targeting the Phase 2 HL-LHC detector upgrades is entering the production phase as mentioned in this paper , after several years of prototyping, the industrialisation of the VTRx + was launched in 2021 and the production is scheduled to start in 2022.
Abstract: Abstract The Versatile Link + project targeting the Phase 2 HL-LHC detector upgrades is entering the production phase. After several years of prototyping, the industrialisation of the Versatile Link + Transceiver (VTRx + ) was launched in 2021 and the production is scheduled to start in 2022. We describe the extensive qualification effort carried out and the quality assurance procedures put in place to monitor the manufacturing quality. We summarise the experience of the industrialisation and we present the plans for the production.

DOI
TL;DR: In this paper , the linear coupling resonance νr - νz = 1 in a cyclotron is driven by the first harmonic in the radial gradient of the radial magnetic field.
Abstract: The linear coupling resonance νr - νz = 1 in a cyclotron is driven by the first harmonic in the radial gradient of the radial magnetic field. In the TRIUMF 500 MeV cyclotron, this resonance is encountered multiple times. When the circulating beam is off-centred radially passing through the resonance, the radial betatron oscillation can be converted into vertical oscillation, which can cause beam losses and radio-activation. We investigated this resonance with goal to correct it by using the available harmonic correction coils. Moreover, we improved the cyclotron vertical tune measurement by using trim coils to create a flat-top radial field, and thus confirmed an extra νr - νz = 1 coupling resonance passage as this is unexpected from the historical tune diagram. To avoid this passage, the local vertical tune is adjusted to stay farther away from the resonance line by using the trim coils axial field, but at the cost of a local excursion in isochronism. After the correction and the avoidance of this resonance, both the coherent and incoherent vertical oscillations are decreased, thus helping to reduce the machine tank spills under high intensity operation. In this paper, we present the results of calculations and simulations as well as measurements that we undertook.

Journal ArticleDOI
TL;DR: In this paper , the ATLAS Inner Detector was replaced by an all-silicon tracker (ITk) consisting of two systems: pixels and strips, which were tested against single event effects due to radiation.
Abstract: Abstract For the high-luminosity upgrade to the LHC, the ATLAS Inner Detector will be replaced by an all-silicon tracker (ITk) consisting of two systems: pixels and strips. HCC and AMAC are ITk Strip ASICs vital for performing the system readout, monitoring, and control. To ensure these ASICs will successfully operate in the high-radiation environment of the HL-LHC, they need to be tested for radiation tolerance, and tests have been performed using both heavy ions and protons. The ASIC designs were shown to protect against single event effects due to radiation.

Journal ArticleDOI
TL;DR: In this paper , the results of a beam test characterization campaign of 3D trench silicon pixel sensors are presented, and a time resolution in the order of 10 ps was measured both for non-irradiated and irradiated sensors up to a fluence of 2.5 × 10 16 1 MeV n eq cm −2 .
Abstract: Abstract In this paper the results of a beam test characterization campaign of 3D trench silicon pixel sensors are presented. A time resolution in the order of 10 ps was measured both for non-irradiated and irradiated sensors up to a fluence of 2.5 × 10 16 1 MeV n eq cm −2 . This feature and a detection efficiency close to 99% make this sensors one of the best candidates for 4D tracking detectors in High-Energy-Physics experiments.

Journal ArticleDOI
TL;DR: In this article , a method to correct the non-uniformity of the light collected by an array of photosensors in a scintillation detector is presented, based on the knowledge of light response functions of individual sensors.
Abstract: The LUX-ZEPLIN (LZ) detector is a dual-phase liquid xenon time projection chamber (TPC) installed at the Sanford Underground Research Facility (Lead, South Dakota) at a depth of 1478 meters. Although the main objective of LZ is the direct detection of dark matter, its low background environment allows for the search of other rare processes, such as the neutrinoless double beta decay of xenon isotopes 134Xe and 136Xe with the respective Q-values of 826 keV and 2458 keV. The sensitivity of the detector to these decays is directly determined by the energy resolution, which, in turn, is degraded by non-uniformities in detector response. In this work, we present a novel method to correct, in the data, the non-uniformity of the light collected by an array of photosensors in a scintillation detector. This method is based on the knowledge of the light response functions of individual photosensors. With these techniques, we report, at a very early phase of the detector operations, a state-of-the-art energy resolution (σ/μ) of (0.67 ± 0.01)% at 2614 keV for the fiducial volume of 5.6 tonnes of liquid xenon.

DOI
TL;DR: In this article , the authors present the commissioning and running experience acquired over 2 years of operations with the CMS GE1/1 system, with an emphasis on the main issues encountered and how they have been addressed.
Abstract: The CMS GE1/1 system was installed in October 2020 as part of the CMS endcap muon system upgrades for the high-luminosity LHC. Since then, GE1/1 has been commissioned, and it is now participating in the CMS data taking of the LHC Run 3. The 144 GE1/1 detectors are read-out by the VFAT3 chip, which communicates with the µTCA backend through the versatile link. Each detector is equipped with 24 VFAT3, 3 GBTx, 3 VTRx, 2 VTTx, and a Virtex-6 FPGA. In this contribution, we present the commissioning and the running experience acquired over 2 years of operations with the CMS GE1/1 system. The electronics performance results are presented with an emphasis on the main issues encountered and how they have been addressed. We also briefly discuss the status of the future GE2/1 and ME0 GEM stations.

DOI
TL;DR: In this article , high aspect ratio 3D micro-structures filled with neutron converting materials (B4C) on planar silicon detectors have been fabricated and tested with neutrons.
Abstract: Neutron detection is of great importance in many fields spanning from scientific research, to nuclear science, and to medical application. The development of silicon-based neutron detectors with enhanced neutron detection efficiency can offer several advantages such as spatial resolution, enhanced dynamic range and background discrimination. In this work, increased detection efficiency is pursued by fabricating high aspect ratio 3D micro-structures filled with neutron converting materials (B4C) on planar silicon detectors. An in-depth feasibility study was carried out in all aspects of the sensor fabrication technology. Passivation of the etched structures was studied in detail, to ensure good electrical performance. The conformal deposition of B4C with a newly developed process showed excellent results. Preliminary electrical characterisation of the completed devices is promising, and detectors have been mounted on dedicated boards in view of the upcoming tests with neutrons.

Journal ArticleDOI
TL;DR: In this article , a comparison of different reconstruction methods has been carried out based on three sets of hot-rod phantom images captured with an experimental Gamma-camera consisting of a Tungsten-based MURA mask with a 2mm thick 256x256 pixelated CdTe semiconductor detector coupled to a Timepix readout circuit.
Abstract: Imaging distributions of radioactive sources plays a substantial role in nuclear medicine as well as in monitoring nuclear waste and its deposit. Coded Aperture Imaging has been proposed as an alternative to parallel or pinhole collimators, but requires image reconstruction as an extra step. Multiple reconstruction methods with varying run time and computational complexity have been proposed. Yet, no quantitative comparison between the different reconstruction methods has been carried out so far. This paper focuses on a comparison based on three sets of hot-rod phantom images captured with an experimental Gamma-camera consisting of a Tungsten-based MURA mask with a 2mm thick 256x256 pixelated CdTe semiconductor detector coupled to a Timepix readout circuit. Analytical reconstruction methods, MURA Decoding, Wiener Filter and a convolutional Maximum Likelihood Expectation Maximization (MLEM) algorithm were compared to data-driven Convolutional Encoder-Decoder (CED) approaches. The comparison is based on the contrast-to-noise ratio as it has been previously used to assess reconstruction quality. For the given set-up, MURA Decoding, the most commonly used CAI reconstruction method, provides robust reconstructions despite the assumption of a linear model. For single image reconstruction, however, MLEM performed best among analytical reconstruction methods, but took the longest with an average of 13s run time. The fastest reconstruction method is the Wiener Filter with 67ms and mediocre quality. The CED with a specifically tailored training set was able to succeed the most commonly used MURA decoding on average by a factor between 1.37 and 2.60 and a run time of around 300ms.

Journal ArticleDOI
TL;DR: In this article , a CdTe-based linear energy-resolved photon counting (ERPC) pixel sensor with real-time image processing techniques was used to detect low and high density contaminants.
Abstract: Abstract X-ray imagers with spectroscopic capabilities and high photon count rates are finding promising applications in industrial real-time inspection systems. In this context, XSpectra ® combines a CdTe-based linear energy-resolved photon counting (ERPC) pixel sensor with real-time image processing techniques to detect low and high density contaminants. The detection unit makes use of a new analog read-out ASIC that has been designed by Politecnico di Milano to meet strict application requirements both in energy resolution and achievable photon count rate. A room-temperature low-rate spectroscopic characterization of the system at a peaking time of 60 ns showed an average equivalent noise charge of 259 electrons r.m.s. (2.72 keV FWHM in CdTe) and an average FWHM of the 59.5 keV 241 Am line of 3.6 keV, with a 3 σ dispersion in noise performance of ±10% over 256 channels. The detection unit was tested in high incoming photon flux conditions by means of an X-ray tube. Minimal spectral distortion due to pile-up events is obtained up to an Incoming Count Rate of 2.5 Mcps/channel, while the maximum counting capability of energy-resolved events is 2.2 Mcps/channel.

Journal ArticleDOI
TL;DR: In this paper , the authors describe how to train recurrent neural networks in tasks like those used to train animals in neuroscience laboratories, and how computations emerge in the trained networks and how artificial networks and real brains can use similar computational strategies.
Abstract: Synaptic plasticity allows cortical circuits to learn new tasks and to adapt to changing environments. How do cortical circuits use plasticity to acquire functions such as decision-making or working memory? Neurons are connected in complex ways, forming recurrent neural networks, and learning modifies the strength of their connections. Moreover, neurons communicate emitting brief discrete electric signals. Here we describe how to train recurrent neural networks in tasks like those used to train animals in neuroscience laboratories, and how computations emerge in the trained networks. Surprisingly, artificial networks and real brains can use similar computational strategies.