Table of contents

A series of mechanical neutron choppers to operate as a velocity selection system have been developed for the Pennsylvania State Breazeal Reactor (PSBR). This chopper system will provide pulsed epithermal neutrons in the energy range of 0.5–40 eV with 2% or better energy resolution, and with a transmission of 1E-6 or better. Four different chopper geometries have been evaluated for their utility as mechanical neutron choppers. Specifically, Fermi, ring, piston, and disc choppers have been evaluated to assess their potential neutronics performance and mechanical constructability. A series of high-speed disc choppers were selected for the final design, and optimization work was performed to maximize the neutron pulse intensity. It is estimated that the optimized system will produce an epithermal neutron intensity of approximately 96 n/s. This system can also be operated in a time of flight (TOF) configuration such that the neutrons arriving at the source have a white spectrum. This operation can be accomplished by leaving the second stage of choppers in the open position, or by removing it from the beam completely. Such unique source of epithermal neutrons produced by this chopper system will have applications in both prompt and delayed epithermal neutron activation analysis (ENAA), as well as in neutron resonance transmission analysis (NRTA).

Boron neutron capture therapy (BNCT) is a promising cancer treatment that selectively destroys tumor cells using a neutron beam. However, accurately and fast measuring the spatial distribution of neutron flux is critical to ensuring effective treatment. To address this challenge, Micromegas detectors are applied for the first time to measure the spatial distribution of neutron beam flux in BNCT. Due to the high flux, large area, and multiple components of the BNCT beam, the design of readout electronics that can handle high counting rate, large channel numbers, high integration, and discrimination of multiple beam components is challenging. This paper proposes a targeted readout electronics system to overcome this challenge. A modular readout structure based on the PCI Express (PXIe) platform is designed for 384-channel readout. A fully parallel readout structure is developed and fast shaper parameters are optimized to achieve high counting rate for each readout channel. A multi-channel high-speed, large-capacity caching technique is developed to address the high-speed data storage problem. Digital shapers are implemented in field-programmable gate array (FPGA) to achieve high integration. Tests demonstrate that each readout channel can support a counting rate of 800 kHz and achieve an excellent position resolution of 1.4 mm. Furthermore, final tests on the BNCT beam confirm that our system can successfully measure the flux spatial distribution of different neutron components.

CUPID is a next-generation bolometric experiment aiming at searching for neutrinoless double-beta decay with ∼250 kg of isotopic mass of ¹⁰⁰Mo. It will operate at ∼10 mK in a cryostat currently hosting a similar-scale bolometric array for the CUORE experiment at the Gran Sasso National Laboratory (Italy). CUPID will be based on large-volume scintillating bolometers consisting of ¹⁰⁰Mo-enriched Li₂MoO₄ crystals, facing thin Ge-wafer-based bolometric light detectors. In the CUPID design, the detector structure is novel and needs to be validated. In particular, the CUORE cryostat presents a high level of mechanical vibrations due to the use of pulse tubes and the effect of vibrations on the detector performance must be investigated. In this paper we report the first test of the CUPID-design bolometric light detectors with NTD-Ge sensors in a dilution refrigerator equipped with a pulse tube in an above-ground lab. Light detectors are characterized in terms of sensitivity, energy resolution, pulse time constants, and noise power spectrum. Despite the challenging noisy environment due to pulse-tube-induced vibrations, we demonstrate that all the four tested light detectors comply with the CUPID goal in terms of intrinsic energy resolution of 100 eV RMS baseline noise. Indeed, we have measured 70–90 eV RMS for the four devices, which show an excellent reproducibility. We have also obtained high energy resolutions at the 356 keV line from a ¹³³Ba source, as good as Ge semiconductor γ detectors in this energy range.

This work presents a novel approach to water Cherenkov neutrino detector event reconstruction and classification. Three forms of a Convolutional Neural Network have been trained to reject cosmic muon events, classify beam events, and estimate neutrino energies, using only a slightly modified version of the raw detector event as input. When evaluated on a realistic selection of simulated CHIPS-5kton prototype detector events, this new approach significantly increases performance over the standard likelihood-based reconstruction and simple neural network classification.

Low Gain Avalanche Detectors (LGAD) for the High-Granularity Timing Detector (HGTD) are crucial in reducing pileups in the High-Luminosity Large Hadron Collider. Numerous studies have been conducted on the bulk irradiation damage of LGADs. However, few studies have been carried out on the surface irradiation damage of LGAD sensors with shallow carbon implantation. In this paper, the IHEP-IME LGADs with shallow carbon implantation were irradiated up to 2 MGy using gamma irradiation to investigate surface damage. Important characteristic parameters, including leakage currents, breakdown voltage (BV), inter-pad resistances, and capacitances, were tested before and after irradiation. The results showed that the leakage current and BV increased after irradiation, whereas overall inter-pad resistance exhibited minimal change and remained above 10⁹ Ω before and after irradiation. Capacitance was found to be less than 4.5 pF with a slight decrease in the gain layer depletion voltage (V_gl) after irradiation. No parameter affected by the inter-pad separation was observed before and after irradiation. All characteristic parameters meet the requirements of HGTD, and this design can be used to further optimization.

A new coherence imaging spectroscopy (CIS) system has been characterized and validated for measurements of impurity ion velocity in the Compact Toroidal Hybrid (CTH) experiment. CIS is an interferometric technique providing very high spatial resolution of line-integrated ion flows; however, these measurements are highly sensitive to environmental factors such as temperature fluctuations. A compact interferometer design housed in a thermally regulated environment yields CIS measurement variations due to thermal fluctuations of 0.25 km/s. CIS measurements of He⁺ flows in the outer regions of CTH are benchmarked using two optical grating spectrometers. The deviation between the measurements is typically less than 2 km/s for multiple lines of sight which is well within the uncertainties of the diagnostics. Additional experiments demonstrate a moderate robustness of ion flows in the outer region of CTH to changing the vacuum transform, direction of the magnetic field, and plasma current. In contrast, regions of complete flow reversal are observed when a bias probe is inserted into the plasma edge.

The fast reconstruction of charged particle tracks with high efficiency and track quality is an essential part of the online data selection for the ATLAS experiment at the High Luminosity LHC. Dedicated custom designed hardware boards and software simulations have been developed to assess the feasibility of a Hardware Tracking Trigger (HTT) system. The Pattern Recognition Mezzanine (PRM), as part of the HTT system, has been designed to recognize track candidates in silicon detectors with Associative Memory ASICs and to select and reconstruct tracks using linearized algorithms implemented in an Intel Stratix 10 MX FPGA. The highly parallelized FPGA design makes extensive use of the integrated High-Bandwidth-Memory. In this paper, the FPGA design for the PRM board is presented. Its functionalities have been verified in both simulations and hardware tests on an Intel Stratix 10 MX development kit.

In this work we demonstrate that ultra-thin (5 and 15 nm) MgO transmission dynodes with sufficient high transmission electron yield (TEY) can be constructed. These transmission dynodes act as electron amplification stages in a novel vacuum electron multiplier: the Timed Photon Counter. The ultra-thin membranes with a diameter of 30 μm are arranged in a square 64-by-64-array. The TEY was determined with a scanning electron microscope using primary electrons with primary energies of 0.75–5 keV. The method allows a TEY map of the surface to be made while simultaneously imaging the surface. The TEY of individual membranes can be extracted from the TEY map. An averaged maximum TEY of 4.6±0.2 was achieved by using 1.35 keV primary electrons on a TiN/MgO bi-layer membrane with a layer thickness of 2 and 5 nm, respectively. The TiN/MgO membrane with a layer thickness of 2 and 15 nm, respectively, has a maximum TEY of 3.3±0.1 (2.35 keV). Furthermore, the effect of the electric field strength on transmission (secondary) electron emission was investigated by placing the emission surface of a transmission dynode in close proximity to a planar collector. By increasing the electric potential between the transmission dynode and the collector, from -50 V to -100 V, the averaged maximum TEY improved from 4.6±0.2 to 5.0±0.3 at a primary energy of 1.35 keV with an upper limit of 5.5 on one of the membranes.

Measurements of the interaction of positively charged particles with bent crystals were obtained by developing a new and consolidated analysis method, for the use of UA9 collaboration. The method was deployed to characterize crystals with a length of a few mm along the beam direction and a bending angle in the order of 10 μrad to 100 μrad, typically exploited in the CERN accelerators. To assess their properties and quality, the crystals have been investigated in the Super Proton Synchrotron North Area with a beam of mixed hadrons at 180 GeV. The UA9 telescopic tracker has been used to collect the data. Some of them are used in the present study to describe and validate the applied data-analysis methodology.

The first detailed study on the performance of a ZnO-based cryogenic scintillating bolometer as a detector to search for rare processes in zinc isotopes was carried out. A 7.2 g ZnO low-temperature detector, containing more than 80% of zinc in its mass, exhibits good energy resolution of baseline noise 1.0–2.7 keV FWHM at various working temperatures resulting in a low-energy threshold for the experiment, 2.0–6.0 keV. The light yield for β/γ events was measured as 1.5(3) keV/MeV, while it varies for α particles in the range of 0.2–3.0 keV/MeV. The detector demonstrates an effective identification of β/γ events from α events using time-properties of only heat signals. The radiopurity of the ZnO crystal was evaluated using the Inductively Coupled Plasma Mass Spectrometry, an ultra-low-background High Purity Ge  γ-spectrometer, and bolometric measurements. Only limits were set at the level of (1–100) mBq/kg on activities of  ⁴⁰K, ¹³⁷Cs and daughter nuclides from the U/Th natural decay chains. The total internal α-activity was measured as 22(2) mBq/kg, with a major contribution caused by 6(1) mBq/kg of ²³²Th and 12(2) mBq/kg of  ²³⁴U. Limits on double beta decay (DBD) processes in ^64Zn and ⁷⁰Zn isotopes were set on the level of (10¹⁷–10¹⁸) yr for various decay modes, profiting from 271 h of acquired background data in the above-ground lab. This study shows a good potential for ZnO-based scintillating bolometers to search for DBD processes of Zn isotopes, especially in ⁶⁴Zn, with the most prominent spectral features at ∼ 10–20 keV, like the two-neutrino double electron capture. A 10 kg-scale experiment can reach the experimental sensitivity at the level of  (10²⁴) yr.

High-resolution beam telescopes for charged particle tracking are one of the most important and equally demanding infrastructure items at test beam facilities. The main purpose of beam telescopes is to provide precise reference track information of beam particles to measure the performance of a device under test (DUT). In this report the development of the ADENIUM beam telescope (ALPIDE sensor based DESY Next test beam  Instrument) as a demonstrator and prototype for a next-generation beam telescope is presented. The ADENIUM beam telescope features up to six pixelated reference planes framed by plastic scintillators for triggering. ADENIUM is capable of replacing the currently used EUDET-type beam telescopes without impacting existing DUT implementations due to the integration of the telescope DAQ into EUDAQ2. In this report the concept and design of the ADENIUM telescope as well as its performance are discussed. The telescope's pointing resolution is determined in different configurations. For an optimal setup at a momentum of 5.6 GeV with an ALPIDE as DUT, a resolution better than 3 μm has been extracted. No rate limitations have been observed at the DESY II test beam.

In brachytherapy, since a radioactive source is inserted into the human body to kill tumor tissue, it is important to accurately determine the positional accuracy of the source. In this study, we aimed to develop a dosimeter that can be used for brachytherapy using CsPbBr₃. This material can replace existing materials for radiation detectors because it is cheaper than others and has a simple manufacturing process. In addition, the basic performance of the dosimeter was evaluated by analyzing reproducibility, linearity, position (distance) dependence, and angular dependence with the ¹⁹²Ir source. As a result of the reproducibility evaluation, the relative standard deviation (RSD) was 1.07%, which satisfied the standard deviation criteria of 1.50%. As a result of the linearity evaluation by linear regression analysis, the R² value was 0.9991, which was higher than the standard criterion of an R² value of 0.9990. As a result of the position (distance) dependence evaluation, the signal value decreased exponentially and uniformly according to the inverse square law of the distance up to 3 cm. As a result of angular dependence evaluation, the signal value of the dosimeter 10 cm away from the front of the source was 5.64 μC, and the signal values of the dosimeter 10 cm away from the sides of the source were 8.49 μC on the left and 8.91 μC on the right. From these four results of reproducibility, linearity, position (distance) dependence, and angular dependence, we anticipate that the manufactured CsPbBr₃ dosimeter with performance outcomes beyond the standards can be used as a dosimeter for brachytherapy.

This article reports the laser calibration of the hadronic Tile Calorimeter of the ATLAS experiment in the LHC Run 2 data campaign. The upgraded Laser II calibration system is described. The system was commissioned during the first LHC Long Shutdown, exhibiting a stability better than 0.8% for the laser light monitoring. The methods employed to derive the detector calibration factors with data from the laser calibration runs are also detailed. These allowed to correct for the response fluctuations of the 9852 photomultiplier tubes of the Tile Calorimeter with a total uncertainty of 0.5% plus a luminosity-dependent sub-dominant term. Finally, we report the regular monitoring and performance studies using laser events in both standalone runs and during proton collisions. These studies include channel timing and quality inspection, and photomultiplier linearity and response dependence on anode current.

This paper reports the development of a numerical solver aimed to simulate the interaction between the space charge (i.e. ions) distribution and the electric field in liquid argon time projection chamber (LArTPC) detectors. The ion transport equation is solved by a time-accurate, cell-centered finite volume method and the electric potential equation by a continuous finite element method. The electric potential equation updates the electric field which provides the drift velocity to the ion transport equation. The ion transport equation updates the space charge density distribution which appears as the source term in the electric potential equation. The interaction between the space charge distribution and the electric field is numerically simulated within each physical time step. The convective velocity in the ion transport equation can include the background flow velocity in addition to the electric drift velocity. The numerical solver has been parallelized using the Message Passing Interface (MPI) library. Numerical tests show and verify the capability and accuracy of the current numerical solver. It is planned that the developed numerical solver, together with a Computational Fluid Dynamics (CFD) package which provides the flow velocity field, can be used to investigate the space charge effect on the electric field in large-scale particle detectors.

The multiple thresholds used in multi-voltage threshold (MVT) method provide more detailed information about the pulse amplitude of the input analog pulses than the simple time-over-threshold (TOT) method, thus allowing for better energy estimation and pulse reconstruction capabilities. However, as the number of thresholds increases, the number of comparators and digital signal readout channels required for MVT also increases. This requirement owing to the increased number of thresholds is the main disadvantage of MVT implementation using field-programmable gate array (FPGA)-based time-to-digital converters (TDCs) because the FPGA resources required for TDC implementation are substantial and FPGAs have a limited number of input/output ports. Therefore, we propose a new single-line MVT method to improve the integrity of the FPGA-only data acquisition system without analog-to-digital converters by reducing the FPGA input channels required for the MVT method. The proposed method, which applies three different levels of thresholding, reduces the digital output signal line in the MVT by employing a 3-input XOR logic gate. The XOR gate integrates the output signals from the comparators and generates 1-bit line digital pulse train. We evaluated the energy performance of the proposed single-line MVT method using three different energy estimators. The energy estimates were compared with the ground truth energy calculated using domino-ring-sampler 4 (DRS4)-sampled analog pulses. The proposed method showed virtually equivalent energy resolution to that of DRS4-based pulse digitization method and better energy linearity than the conventional TOT method. Among the energy estimation methods used in single-line MVT, the crossing-point triangular sum method showed the best energy linearity. The proposed single-line MVT method will be useful when data acquisition systems without ADCs are implemented using FPGA-based TDCs. This is because the proposed method alleviates the problem of limited input ports and the numerous resources required for TDCs in FPGAs.

Bhabha Atomic Research Centre is developing Low Energy High Intensity Proton Accelerator (LEHIPA) as a pre-injector for proposed Accelerator Driven Sub-Critical Reactor Systems (ADSS). Drift Tube Linac is one of the two major accelerating structures of LEHIPA, the other being the Radio Frequency Quadrupole (RFQ). Like all particle accelerating structures, DTL needs multi-disciplinary expertise for design, production, qualification, and installation. This paper describes the comprehensive design, production, qualification, and installation of the ∼ 11–20 MeV section of DTL. It details the design of all sub-components which form part of the DTL RF cavity. Several novel concepts were implemented in course of this development. Important among them are DT-DTL alignment, referencing methodology, robust vacuum design and hermetically sealed DTs. This paper is a comprehensive coverage of design, development and installation aspects of Alvarez DTL. At present, the DTL is ready for beam commissioning.

In this study, the response of a Twin Frisch-grid ionization chamber (TFGIC) to fission fragments (FFs) was investigated using finite element and Monte Carlo methods. The entire process of the fission experiments, including FFs generation, gas ionization, electron drift and collection, and induced charge signal were well reproduced. Through data analysis, pulse height spectra from the anode and grid were transformed into energy and emission-angle information for the FFs. By means of double energy method, the pre-neutron emission fission fragment mass and total kinetic energy (TKE) can be finally determined. Experimental and calculated data of the mass and TKE distribution are shown in good agreement.

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.

With the development and application of Brain-Computer Interface (BCI), the demand for the portability, transmission performance, sampling rate, and number of channels of electroencephalogram (EEG) acquisition devices is increasing. The high-performance acquisition devices used in current research are generally large in size which limit its application scenarios, while portable high-performance acquisition devices have a limited wireless transmission bandwidth. To tackle these issues, a high-performance multichannel wireless EEG acquisition system was designed, the acquisition device is powered independently by a battery, controls the bioelectric acquisition chip through FPGA (filed-programmable gate array) to achieve high-speed and stable processing of EEG data, and transmits it in real-time via Wi-Fi to the host computer for display and recording. Standard signal source tests and Electrocorticography (ECoG) acquisition experiments demonstrate that the system performed well with 64 channels and a maximum sampling rate of 30 kHz within a distance of 10 meters. This design provides a new solution for neuroscience research scenarios.

In the context of the upgrade of the Large Hadron Collider at CERN for high-luminosity operation, the particle detectors have to cope with much higher data rates and therefore need to upgrade their data acquisition systems. This upgrade is taken as an opportunity to exchange the currently used highly customized hardware by commercial solutions. Nevertheless, some part of the data processing still needs to be done within Field Programmable Gate Arrays (FPGA), requiring the transfer of data between the FPGAs and the commercial servers. This paper reports on a study of direct data transmission from FPGAs to servers via a commercial network. Large data buffers as required for reliable data-transmission protocols are avoided by using an emerging technique named eXpress Data Path (XDP). Based on XDP, the transmission of 5.2 PB (i.e. 2.92 × 10¹²  packets) was achieved within 168 h without a single missing packet.

The Super Tau-Charm Facility (STCF) is a future electron-positron collider operating in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 10³⁵ cm^-2s^-1. A high-performance detector is required for the STCF experiment to meet the STCF physics goals. A low-material cylindrical inner tracker based on the micro-resistive well detector (μRWELL) is proposed for the STCF experiment. In this paper, the design of the μRWELL inner tracker is presented. A good balance between material budget, structural strength, and detector performance is achieved in the design where the material budget of the μRWELL inner tracker is estimated to be 0.29% X/X₀, a 40% reduction w.r.t. that of the cylindrical gas electron multiplier (CGEM) detector used at the KLOE experiment. The hit position of the detector is reconstructed using an algorithm combing the micro-time projection chamber (μ-TPC) method and the charge center-of-gravity method. The detector performance was studied in detail using simulation with Garfield and Geant4. With the optimum working gas of Ar: CO₂ = 85:15, this detector can obtain a spatial resolution better than 100 μm and 400 μm in 1 T magnetic field in rφ and beamline direction, respectively. The simulated momentum resolution and vertex resolution of the whole STCF tracking system including the μRWELL inner tracker and a large drift chamber can meet the requirements for the STCF detector, benefiting from the optimized inner tracker design.

The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring based light source, which is under construction in Beijing, China. The HEPS accelerator consists of a Linac, a booster, a storage ring and three transfer lines. Installation and high-power conditioning of the Linac has been completed. For beam commissioning and measurements of the HEPS Linac, it is necessary to develop high level applications (HLAs). The development of the Linac HLAs, based on the framework named Python accelerator physics application set(Pyapas), has been completed. All the applications are physics quantity based, including measurement applications, control applications and monitoring applications. All the applications have been tested and verified on virtual accelerator. The results show the validity of the algorithm and indicate that the developed applications could meet the requirements of Linac commissioning. All the applications have been deployed to the actual machine environment and communication and control test with hardware system have been completed.

We present the first beam test results with centimeter-scale AC-LGAD strip sensors, using the Fermilab Test Beam Facility and sensors manufactured by the Brookhaven National Laboratory. Sensors of this type are envisioned for applications that require large-area precision 4D tracking coverage with economical channel counts, including timing layers for the Electron Ion Collider (EIC), and space-based particle experiments. A survey of sensor designs is presented, with the aim of optimizing the electrode geometry for spatial resolution and timing performance. Several design considerations are discussed towards maintaining desirable signal characteristics with increasingly larger electrodes. The resolutions obtained with several prototypes are presented, reaching simultaneous 18 μm and 32 ps resolutions from strips of 1 cm length and 500 μm pitch. With only slight modifications, these sensors would be ideal candidates for a 4D timing layer at the EIC.

The extended physics program of the SuperCDMS SNOLAB dark matter search experiment aims to maximize the sensitivity to low-mass dark matter. To realize this, an upgrade of the existing level-1 trigger of the data acquisition system is proposed by making use of a recurrent neural network to be implemented on the trigger FPGA. This provides an improved amplitude estimator and signal-noise discriminator based on the combined information of filtered traces from individual detector channels. The architecture and configuration of this neural trigger are discussed in this article, and the improvements in key performance indicators such as the efficiency, resolution, and noise rate are quantified based on signal simulations and noise data. Based on the findings in this proof of concept, the trigger threshold is expected to be lowered by  ∼ 22%.

Generation of short electron bunches with high peak current is of great importance for different research and technological applications. Such generation requires a special bunching magnetic system. This paper describes a new scheme of a magnetic buncher for relativistic electrons. The buncher provides a strong dependence of the time of flight on the particle energy and thus is capable to bunch relatively long bunches to short ones.

This paper presents an energy calibration scheme for an upgraded reactor antineutrino detector for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). The PROSPECT collaboration is preparing an upgraded detector, PROSPECT-II (P-II), to advance capabilities for the investigation of fundamental neutrino physics, fission processes and associated reactor neutrino flux, and nuclear security applications. P-II will expand the statistical power of the original PROSPECT (P-I) dataset by at least an order of magnitude. The new design builds upon previous P-I design and focuses on improving the detector robustness and long-term stability to enable multi-year operation at one or more sites. The new design optimizes the fiducial volume by elimination of dead space previously occupied by internal calibration channels, which in turn necessitates the external deployment. In this paper, we describe a calibration strategy for P-II. The expected performance of externally deployed calibration sources is evaluated using P-I data and a well-benchmarked simulation package by varying detector segmentation configurations in the analysis. The proposed external calibration scheme delivers a compatible energy scale model and achieves comparable performance with the inclusion of an additional AmBe neutron source, in comparison to the previous internal arrangement. Most importantly, the estimated uncertainty contribution from the external energy scale calibration model meets the precision requirements of the P-II experiment.

In this work we present an application of the Goertzel Filter for the channelization of multi-tonal signals, typically used for the read-out of cryogenic sensors which are multiplexed in the frequency domain (FDM), by means of Microwave Superconducting Quantum Interference Device (SQUID) Multiplexer (μMUX). We demonstrate how implementing a bank of many of these filters, can be used to perform a channelization of the multi-tonal input signal to retrieve the data added by the sensors. We show how this approach can be implemented in a resource-efficient manner in a Field Programmable Gate Array (FPGA) within the state-of-the-art, which allows great scalability for reading thousands of sensors; as is required by Radio Telescopes in Cosmic Microwave Background Radiation (CMB) surveys using cryogenic bolometers, particles detection like Neutrino mass estimation using cryogenic calorimeters or Quantum Computing.

In this paper, the Low Power Giga Bit Transceiver (lpGBT) built-in system for environmental monitoring of the LHC experiments is presented. Eight external analogue inputs and eight internal voltages are multiplexed into an instrumentation amplifier with selectable gain, whose output is digitised by a 10-bit SAR ADC. A programmable current source can be enabled for each external input to implement resistance measurements. Internal channels are used to monitor power supplies and the output of the temperature sensor. The environmental monitoring system includes a precise 1 V reference voltage source and a 10-bit voltage DAC. All blocks were designed and fabricated in 65 nm CMOS technology, fully characterised, and the pre- and post-irradiation measurement results are presented in this work.

We use Fréchet Inception Distance (FID) measured in the latent spaces of pre-trained, fine-tuned and custom-made inception networks to evaluate Generative Adversarial Networks (GANs) developed by the COherent Muon to Electron Transition (COMET) collaboration to generate sequences of background hits in a Cylindrical Drift Chamber (CDC). We validate the convergence of the GANs' training and show that the use of self-attention layers reduces FID. Our method enables the use of FID as an evaluation metric even when an application-specific inception network is not readily available, making it transferable to other GAN applications in High Energy Physics.

We have set up a diagnostic magnet (D-Mag) laboratory for a wide range of applications in plasma physics. It consists of a superconducting magnet for field strengths of up to 5.9 T. The main purpose is to provide an experimental environment for the development of plasma diagnostics for nuclear fusion studies and the investigation of dusty plasmas in strong magnetic fields. We describe in the article the setup and operation of the D-Mag. Some applications are presented for the development of plasma diagnostics, such as neutral pressure gauges and Langmuir probes that have to be operated in strong magnetic fields. Among the examples is the test of the long-pulse capability and stability of the diagnostic pressure gauge (DPG) for the ITER device.

Generative Adversarial Networks trained on samples of simulated or actual events have been proposed as a way of generating large simulated datasets at a reduced computational cost. In this work, a novel approach to perform the simulation of photodetector signals from the time projection chamber of the EXO-200 experiment is demonstrated. The method is based on a Wasserstein Generative Adversarial Network — a deep learning technique allowing for implicit non-parametric estimation of the population distribution for a given set of objects. Our network is trained on real calibration data using raw scintillation waveforms as input. We find that it is able to produce high-quality simulated waveforms an order of magnitude faster than the traditional simulation approach and, importantly, generalize from the training sample and discern salient high-level features of the data. In particular, the network correctly deduces position dependency of scintillation light response in the detector and correctly recognizes dead photodetector channels. The network output is then integrated into the EXO-200 analysis framework to show that the standard EXO-200 reconstruction routine processes the simulated waveforms to produce energy distributions comparable to that of real waveforms. Finally, the remaining discrepancies and potential ways to improve the approach further are highlighted.

With the rapid development and wide application of cryogenic, superconducting and space technologies in engineering fields, measurements of the mechanical properties especially the tensile properties of small-sized samples at cryogenic temperatures are more and more important. In this study, a tensile property measuring system for miniaturized samples was designed and built, where the samples can be measured from 300 K to 70 K with a resolution of 0.1 K. The cryogenic environment was provided by a pulse tube cryocooler. The force load applied to the sample was up to 10 N with a resolution of 0.001 N. The structure of the cryogenic system and sample holders were specially designed for miniaturized samples. A control and automatic data acquisition system was used to control and acquire data from all devices of the instrument. The simulations of the stretching part under load at cryogenic temperature were performed to ensure the measurement accuracy and reliability. To verify the performance and accuracy of the system, the tensile properties of two kinds of fine high-purity copper wires were measured at both 77 K and 300 K. The tensile measurement results were discussed and the measurement uncertainty of the system was analyzed. With different clamps more kinds of mechanical measurements of miniaturized samples can be carried out on this system.

The National Synchrotron Radiation Laboratory is planning to build a 2.2 GeV diffraction-limited storage ring, the Hefei Advanced Light Facility (HALF), with a 6BA lattice structure and a large number of longitudinal gradient bends (LGBs). In order to increase the radiated photon energy to the hard X-ray band and to reduce the natural emittance, a superconducting longitudinal gradient bend (SLGB) magnet is planned to be used on HALF in the future, which requires a magnetic field integral of 0.40 T·m over a length of 0.46 m and a peak field of about 5 T. A SLGB has many structural parameters, such as the geometric parameters of the superconducting coils and the thickness of the yoke, etc. Their influence on the magnetic field distribution has been studied, although the computation of the 3D magnet model is very slow. Considering the longitudinal field variation, the vertical gap limitation, the field homogeneity requirement and the critical current of the superconducting wire, a method is developed to simplify the 3D magnet simulation by a corresponding 2D model, so that the longitudinal magnetic field profile of a 3D model can be approximately calculated in a 2D model with faster speed. Due to the faster calculation speed of 2D models, a Mathematica-based optimization program is developed and relatively good structural parameters for the HALF SLGB are found by the program. The simulation results show that the physical design requirements can be well met. The electromagnetic design for the HALF SLGB magnet is based on the current J_C level of NbTi superconductor due to its excellent mechanical performance.

Machine learning methods and in particular Graph Neural Networks (GNNs) have revolutionized many tasks within the high energy physics community. Particularly in the realm of jet tagging, GNNs and domain adaptation have been especially successful. However, applications with lower energy events have not received as much attention. We report on the novel use of GNNs and a domain-adversarial training method to identify Λ hyperon events with the CLAS12 experiment at Jefferson Lab. The GNN method we have developed increases the purity of the Λ yield by a factor of 1.95 and by 1.82 using the domain-adversarial training. This work also provides a good benchmark for developing event tagging machine learning methods for the Λ and other channels at CLAS12 and other experiments, such as the planned Electron Ion Collider.

Neutrino experiments often use large volumes of water, organic scintillators or noble liquids as active detection material. Due to the large hydrostatic and buoyancy forces involved, precise knowledge of the liquid levels inside the detector tank are mandatory. Here we present the main characteristics of the TruSense S310 Laser Range System. Level measurements can be performed without direct contact to the liquid and through a gas-proof acrylic window, thus preserving the strict radiopurity and chemical requirements of the target liquid. We report the results of a suit of laboratory experiments for short-term precision tests (±5 mm) and long-term stability studies. Moreover, we demonstrate that the infrared laser can be used while standard bi-alkali PMTs are operational. We discuss the mechanical layout and integration of the system in the OSIRIS pre-detector that will monitor the radiopurity of the liquid scintillator for the large-volume neutrino experiment JUNO.

Fiber optic sensors based on the fiber Bragg grating (FBG) technology [1] is widely used to produce quasi-distributed monitoring systems to measure mechanical parameters for Structural Health Monitoring (SHM) of civil engineering structures [2]. FBG sensors are produced in the core of the optical fiber, as a short segment of fiber where a diffraction grating is produced (5–10 mm). The principle of operation of the FBGs is based on the diffraction occurring at the grating: if broadband light propagates, a quasi-monochromatic counter propagating light originates. The wavelength of the diffracted light depends on the value of the refraction index of the core along the grating which in turn is affected by both temperature and strain. Thus, by measuring the wavelength change of the counter propagating light, the change of strain and the temperature can be worked out. The PREFOS Project [3] aims to develop a novel procedure to apply the use of FBGs to monitor the prestressed strands of civil engineering prefabricated components. In this paper, we report results of an experimental campaign intended to measure the sensitivity of saddle-like sensors to induced vibration and mechanical strain. Measurements were done performing static and dynamic tests on a steel strand equipped with 3 sensors. The tests have been performed applying different tensioning to the steel strand. Static measurements were worked out applying a stepwise tensioning increase. Dynamic tests were worked out at each stepped tension level, inducing vibration by both sharp hammer impact and release of hanged weight. The paper is organized as follows, in section 1 a general description of the testbed structure used for the experiments will be provided. In section 2 the results of static analysis and dynamic tests will be presented with the dynamic behavior of the strand evaluated by performing a simple Fast Fourier Transform (FFT). Finally, the conclusions will be drawn.

The R&D project being presented aims to improve the use of resistive Micromegas technology in high-energy physics experiments. The project focuses on achieving stable, reliable, and high-gain operation at particle flow rates above 1 MHz/cm² on large surfaces. To achieve this, the project uses a configuration with small pads readout and requires innovative solutions for the spark protection resistive scheme. Different resistive patterns were investigated, and finally the solution based on a double layer of DLC foils was chosen, demonstrating the capability to perform equally for low and high rates under irradiation of X-rays on the full surface of 25 cm² of the prototype detectors. With this technology and layout, a detector with an active area of 400 cm² was recently built. In this work we present the results of high-rate capability, robustness, dependence on the irradiated area, obtained with high intensity X-rays measurements, as well as the results on efficiency and spatial resolution obtained, at low rates, at CERN SPS with high energy particle beams. Additionally, preliminary results of pixelized resistive Micromegas time response are reported. With the successful achievements of this detector and the construction of even larger small-pad resistive Micromegas next year, the project will establish the technology for future use in particle physics and other applications.

Cusp-shaped magnetic fields are widely used to confine plasmas in various applications. This field configuration allows to localise plasma losses: the width of such loss cone, usually called leak width, was found to be proportional to the geometric mean of the ion and electron Larmor radii, so that it becomes smaller for increasing magnetic field intensity. At the same time, plasma diffusion towards the walls is reduced in the regions where the field lines are parallel to the surfaces, leading to the formation of a Plasma Exclusion Zone (PEZ) whose characteristic dimension was found to be proportional to the distance between the magnets. Besides field intensity and geometry, the confinement effectiveness might also be affected by plasma properties such as electron temperature, plasma potential across the sheath and collisionality. Specifically, this contribution describes a numerical analysis performed by means of a 2D-3V Particle-In-Cell code of the dependencies of both the PEZ size and the leak width on magnetic field intensity and plasma potential, focusing on typical conditions found in plasma sources for negative ion beams. The leak width was found to be larger than its theoretical prediction regardless of the specific plasma parameters. The PEZ was found to be affected not only by the distance between the magnets. In particular, the plasma potential was found to strongly affect the plasma behaviour within the cusp region.

The proton-boron aneutronic fusion reaction has numerous potential applications varying from controlled nuclear fusion reactor to broad-energy spectrum α-particle source, as well as uses in medicine, where it can serve as a source for radioisotope production, or directly in proton boron capture therapy. However, proton-boron fusion reaction and its by-products should be investigated extensively to provide a stable and controlled secondary ion source. In order to monitor the multi-ion beam emitted and accelerated from the target surface after interaction with laser pulses, a new Thomson Parabola Spectrometer (TPS) has been designed to differentiate proton and alpha traces in the energy ranges 0.5–5 MeV and 1–10 MeV respectively, with a high energy resolution (≤ 1%), while maintaining compactness of the spectrometer (∼ 20 cm).

The Surface Resistive Plate Counter (sRPC) is a novel RPC based on surface resistivity electrodes, a completely different concept with respect to traditional RPCs that use electrodes characterised by volume resistivity. The electrodes of the sRPC exploit the well-established industrial Diamond-Like-Carbon (DLC) sputtering technology on thin (50 μm) polyimide foils, already introduced in the manufacturing of the resistive MPGDs such as μ-RWELL and MicroMegas, that allows to realise large area (up to 2 × 0.5 m²) electrodes with a surface resistivity spanning over several orders of magnitude (0.01 ÷ 10 GΩ/□). Two detector layout has been developed: the baseline layout with the DLC connected to the HV by a single dot connection outside the active area and the high rate layout with a screen printing a conductive grid onto the DLC film, which exploit the concept of the high density current evacuation scheme first introduced for the μ-RWELL. Besides the use in HEP experiments as timing detector this new technology could be exploited as thermal neutron device for homeland security applications (e.g. Radioactive Portal Monitors for ports and airports), replacing one or both DLC electrodes of the sRPC with plates coated with ∼3 μm thick ¹⁰B₄C layer, thus obtaining neutron converters inside the active volume of the detector. Results obtained by irradiating the detectors at the calibrated  ²⁴¹Am-B ENEA-Frascati HOTNES facility will be discussed.

Removing ambiguities within a single stage becomes crucial when one can not use multiple detectors behind each other to resolve them which naturally is the case for neutral radiation. An example would be RICH detectors. Commonly, pixilated readout is choosen for this purpose. However, this causes a remarkable increase in quantity of channels. Thus, the overall costs of the detector would increase. Therefore, the XYU-GEM was proposed as a three coordinate strip-readout which is combined with a triple GEM detector. The readout complements a common XY readout with an additional projection which is tilted by 45°. The overdetermination due to three projections can be used to resovle ambiguities. Following the detector design will be explained, first measurements discussed to understand the response of the detector and a way to change the charge sharing without changing the manufacturing parameters of the readout.

Time Projection Chambers (TPC)s are excellent tracking detectors for high multiplicity events and can intrinsically be high-rate, but are limited by the ions created in their avalanche stage. GEMs and Micromegas can reduce IBF through their geometry and E͐-field ratios, but these can lead to gain fluctuations and still leave IBF as the dominant source of space charge. An active BPG can block all IBF ions, but their slow drift speed creates too much dead time. A passive BPG will overcome this limitation by using an external B͐-field to allow the electrons to pass through while still blocking all ions. Since the grid changes the electron's trajectory, a loss of resolution will occur. The trajectory is shifted symmetrically along the wires so the wire alignment with respect to the detection pads is a specific question not studied before. We present completed IBF analysis from data collected at Weizmann Institute of Science (WIS), along with an intro to our test on wire resolution.

A caesiated RF driven source delivers H^- ions that, after stripping at the end of the 160 MeV H^- linear injector, provides protons to CERN's accelerator complex including LHC, where the protons reached a record energy of 6.8 TeV. In Caesiated RF sources, H^- ions are produced via dissociative attachment of electrons onto roto-vibrationally excited H₂-molecules (volume) and re-emission as negative ions of protons or hydrogen atoms colliding on a low work function caesiated molybdenum plasma electrode (surface). During initial caesiation, the production mechanism evolves from the initial Cs-free volume production to a predominant surface production mode; the observed stunning reduction of co-extracted electrons is concomitant to an increase of the H^- ion current to RF-power yield. This paper describes the evolution of the beam-profile at today's operational beam intensities of 35 mA for various ratios of volume and surface ion-origin. The presence of surface produced ions occurring on a conical plane is characterized by the electron to ion ratio and by measurement of the Cs-coverage of the molybdenum plasma electrode down to a fraction of a monolayer. Angular distributions are extracted from beam profile and Beam Emission Spectroscopy (BES) measurements. These experimental results provide an initial comparison to beam formation simulation that, at a later stage, could be coupled to beam transport software packages. The paper focuses on the caaesiation transient to present experimental evidence for 3D beam formation studies, it provides insight into the mixing of volume and surface production modes, reduction of co-extracted electrons and Cs-coverage. The paper also establishes magnetic field induced asymmetries in the beam's current density.

To enhance the performance of micro-patterned gaseous detectors (MPGDs) to meet the challenging requirements of future high energy physics (HEP) experiments, two-dimensional (2D) materials are attractive candidates to address the back flow of positive ions, which affects detector performance by distorting electric field lines. In this context, graphene is promising to work as selective filter for ion back flow suppression, being transparent to electrons while at the same time blocking ions. Also, graphene membranes can physically separate drift and amplification regions of the detectors, offering additional flexibility in the choice of gas mixtures and allowing independent optimizations of detector sensitivity and electron multiplication processes. Here we present an approach to integrate graphene grown via chemical vapor deposition (CVD) on gaseous electron multiplier (GEM) prototypes via a wet transfer procedure in order to suspend graphene over thousands of holes with 60 μm diameter and overcome the challenges encountered due to process steps involving liquids, mostly related with the capillary effects during drying and evaporation of them. In order to overcome the risk of damaging the membrane and decreasing the yield of suspended 2D material membranes, critical point dryer (CPD) and inverted floating method (IFM) procedures are investigated. In addition to the necessity to cover the full holes in the active area, polymeric residuals have to be minimized in order to evaluate the graphene transparency at the electron energies (i.e., < 15 eV) typically obtained in the operating conditions, measurements in these energy ranges are still not deeply investigated.

The J-PARC E16 experiment measures mass spectra of low-mass vector mesons,  ρ, ω, and ϕ, in nuclei via e⁺e^- decays. Vector mesons are produced inpA reactions. A spectrometer with a large acceptance and a high-intensity beam up to 1 × 10¹⁰ protons per ∼2-sec duration pulse are utilized to collect a sufficient number of vector mesons. We have developed a spectrometer, which has two types of electron identification detectors: a hadron blind detector (HBD) and a lead-glass calorimeter. Commissioning runs have been performed at the J-PARC high-momentum beam line. The HBD successfully observed on average 11 ± 1 photoelectrons for an incident electron. We achieved the pion rejection of 0.9 ± 0.2% with the electron detection efficiency of 61 ± 4% for the HBD, which was consistent of the expected performance.

We present a gas selection for Xe-based gas electron multiplier (GEM) detectors, Gas Multiplier Counters (GMCs) onboard the CubeSat X-ray observatory NinjaSat. To achieve an energy bandpass of 2–50 keV, we decided to use a Xe-based gas mixture at a pressure of 1.2 atm that is sensitive to high-energy X-rays. In addition, an effective gain of over 300 is required for a single GEM so that the 2 keV X-ray signal can be sufficiently larger than the electrical noise. At first, we measured the effective gains of GEM in nine Xe-based gas mixtures (combinations of Xe, Ar, CO₂, CH₄, and dimethyl ether; DME) at 1.0 atm. The highest gains were obtained with Xe/Ar/DME mixtures, while relatively lower gains were obtained with Xe/Ar/CO₂, Xe/Ar/CH₄, and Xe+quencher mixtures. Based on these results, we selected the Xe/Ar/DME (75%/24%/1%) mixture at 1.2 atm as the sealed gas for GMC. Then we investigated the dependence of an effective gain on the electric fields in the drift and induction gaps ranging from 100–650 V cm^-1 and 500–5000 V cm^-1, respectively, in the selected gas mixture. The effective gain weakly depended on the drift field while it was almost linearly proportional to the induction field: 2.4 times higher at 5000 V cm^-1 than at 1000 V cm^-1. With the optimal induction and drift fields, the flight model GMC achieves an effective gain of 460 with an applied GEM voltage of 590 V.

In the last years, optical readout of Micromegas gaseous detectors has been achieved by implementing a Micromegas detector on a glass anode coupled to a CMOS camera. Effective X-ray radiography was demonstrated using integrated imaging approach. High granularity values have been reached for low-energy X-rays from radioactive sources and X-ray generators. Detector characterization with X-ray radiography has led to two applications: neutron imaging for non-destructive examination of highly gamma-ray emitting objects and beta imaging for the single cell activity tagging in the field of oncology drug studies. First measurements investigating the achievable spatial resolution of the glass Micromegas detector at the SOLEIL synchrotron facility with a high-intensity and flat irradiation field will be shown in this article.

Within the effort on the conceptual design of the Divertor Test Tokamak (DTT) Neutral Beam Injector (NBI), the design of the Stray Field Shielding System (SFSS) for DTT NBI is under development, to suppress the potentially harmful effects of the stray poloidal field from the tokamak on the accelerated charged beam. Various possible design solutions to solve this problem are presented and compared, with a particular focus on the stray field minimization procedure and particle tracing simulations, used during the design validation phase with the objective of maximizing beamline performances.

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.

The Large Hadron Collider (LHC) and the experiments installed there are being upgraded for the High Luminosity LHC project that will provide a greatly enlarged data sample in the search for physics beyond the Standard Model. During Long Shutdown 2, from 2018 to the first months of 2022, some of these upgrades were completed. In particular, the muon spectrometer of the CMS experiment was upgraded with installation of the GE1/1 detector station, based on Gas Electron Multiplier (GEM) technology. This station is positioned in the endcap region of the CMS muon system and covers the pseudorapidity range 1.55 < |η| < 2.18. On the 5th of July, 2022, Run 3 of the LHC began with collision energy of 13.6 TeV. The newly installed GEM detectors experienced high-voltage discharges when the beams were colliding inside CMS. To monitor these events and to understand how to safely operate the detectors, a study of these phenomena became necessary. The intensity of discharge current and the discharge rate were recorded in different detectors as a function of luminosity and time. It was observed that some chambers have a significantly higher discharge rate than the modal value of rate over the entire chamber population. The reasons responsible for this behavior are currently under investigation. In this contribution, an analysis of discharges will be presented, illustrating the dependence of discharge rate on different LHC beam configurations and the high voltage working point of the chambers.

In this study, we investigate the impact of humidity on the performance of a THGEM operated with an Ar-CO₂ gas mixture. The water content is introduced in a range of 0–4000 ppmV. It is observed that the presence of increased humidity does not degrade any of the studied performance criteria. On the contrary, our measurements suggest an improvement in discharge stability with increasing humidity levels at the highest gains and fields. No significant difference is observed at the lower gains, indicating that humidity helps to avoid spurious discharges related to electrode defects or charging-up of the insulating layers. We conclude that adding a small amount of water to the gas mixture may be beneficial for the stable operation of an MPGD.

In general, a quality of negative ion beam optics is determined by the shape of the plasma meniscus, which is an ion emitting surface. In this study, the key parameters to control the plasma meniscus and relevant physical structure in the electronegative plasma including the surface produced H^- ions is investigated by using PIC-MCC simulation. The region from the source plasma up to the accelerator is modeled for a single aperture, and thus, the plasma meniscus can be obtained self-consistently. Parameter survey for the net flux of surface produced H^- ion is conducted by varing the numbers of the surface produced H^- ion super-particles per timestep in order to investigate the effcet of the electronegativity, that is, the ratio of the negative ion density to the electron density. It is shown that the effective distance d_eff, between the plasma meniscus and the extraction grid depends on the electronegativity as well as the plasma density. Especially, the effective distance d_eff, decreases with the increase of the electronegativity under the constant plasma density, which means that the shape of the plasma meniscus becomes flat or convex rather than concave. Moreover, it is also verified that the electronegativity affects the H^- ion trajectories extracted from near the edge of plasma meniscus through the shape of plasma meniscus.

MIMOSIS is a CMOS Monolithic Active Pixel Sensor (CPS) developed to equip the Micro Vertex Detector (MVD) of the Compressed Baryonic Matter (CBM) experiment at FAIR/GSI. The sensor will combine a spatial resolution of -5 µm with a time resolution of 5 µs and provide a peak hit rate capability of ∼80 MHz/cm². To fulfil its task, MIMOSIS will have to withstand ionising radiation doses of ∼5 MRad and fluences of ∼7 × 10¹³ n_eq/cm² per year of operation.

The paper summarises major requirements of the CBM-MVD and compares them to the detection performances of the first full scale prototype, called MIMOSIS-1, recently evaluated in the laboratory and with particle beams. The tolerance of the sensor to the expected ionising radiation load was evaluated; the paper describes the measurements performed and their outcome.

NEWAGE is the experiment of direction-sensitive dark matter search using low pressure gaseous TPC with micro pattern strip readout (μ-PIC). It allows to measure the distribution of angles of WIMP-nuclear recoil by track reconstruction, and it allows a positive signature of dark matter. In recent years, large size (∼1 m³) TPC filled with SF₆ gas, which is so called "negative-ion gas", is under development. A TPC with negative ions is a novel technology for the measurement of absolute position of drift direction coordinates in a self-triggering system. The determination of the absolute track position allows to discriminate nuclear recoils in the target gas volume from alpha-rays from the detector surface, which is one of the background sources. Furthermore, diffusion of drifting negative ions is expected to be lower than that of nominal electron drift, which allows to improve angular resolution. This presentation reports the status of the development of negative-ion gaseous TPC with a prototype small chamber. In addition, we started to develop O(100) μm pitch gaseous TPC detector with pixel type readout system to achieve reconstruction of short track nuclear recoils with good angular resolution. It enables to explore lower mass region of direction-sensitive dark matter searches. We also report about the status of the pixel detector development.

In this study we investigate the stability limits of Micromegas detectors upon irradiation with alpha particles. The results are obtained with meshes with different optical transparency and geometry of wires. The measurements are performed in Ar- and Ne- based mixtures with different CO₂ content. We observe that the breakdown limit strongly depends on the gas and that a higher amount of quencher in the mixture does not necessarily correlate with higher stability. In addition, we observe discharge probability scaling with the wire pitch. This suggests that a Micromegas mesh cell can be treated as an independent amplification unit, similar to a hole in a GEM foil. The outcome of these studies provides valuable input for further optimization of MPGD detectors, multi-layer stacks in particular.

This study presents techniques for the mass production of large-sized GEM foils for the CMS phase-2 upgrade by the Korean CMS group. The foil production facility is designed with a focus on mass production, including the adoption of the double-mask technique. A polyimide wet etching technology that uses mono ethanolamine is reported, providing a safer working environment due to its lower inhalation toxicity compared to ethylene diamine. The study also covers the denaturation of the etchant over time and the process of retuning. Finally, R&D results on soldering surface mount resistors with hot air for faster production are discussed.

Flip-chip bonding is a common method for joining application-specific integrated circuits (ASIC) to pixel sensors in order to build hybrid radiation detectors for X-rays and gamma-rays. STFC-RAL is using two methods for the interconnects between ASIC and sensor pixels. These are either indium bumps which are deposited on ASIC and sensor prior to bonding or alternatively electrically conductive adhesive dots are printed on the sensor pixel array and flip-chip bonded to gold studs attached to each pixel of the ASIC. Conventionally the indium deposition is carried out on wafer-scale using a photolithographic lift-off process. Sensor and ASIC with indium bumps are singulated from wafers afterwards. Some sensor material (e.g. CdZnTe) which is required for high-energy and high-flux X-ray detectors at X-ray Free Electron Lasers (XFEL) or in other scientific experiments is only available as individual die instead of wafers. The stencil printing of conductive epoxy dots onto those sensor dies together with gold ball studding of ASICs is a suitable method for those dies. However, due to the size of printed epoxy dots this method has a limited pixel pitch and is currently only used for sensors with 250 μm-pitch or for larger pitch. A novel method for indium deposition was developed for such dies. A shadow mask with small apertures is optically aligned to the pixel array and mechanically clamped to the sensor die. After indium evaporation onto this assembly and after removal of the mask, indium bumps as small as 50 μm with a height of ∼ 5 μm are deposit onto the pixel array of the sensor. The same is done for a matching ASIC. A comparison of these two methods indicates that indium bumps created by the shadow mask technique are approx. half the size of the epoxy dots and comparable with gold studs. Using this method, at present a pitch of 100 μm for those indium bumps can be achieved and development for further improvement towards smaller pitch is carried out currently. This novel indium deposition method is compared with the conventional wafer-scale indium lift-off method and the epoxy/gold stud flip-chip bonding in terms of interconnect quality, bond yield, and suitability for hybrid radiation detectors.

Compact large-area dielectric photon detectors that ensure modular noble liquid detectors can sense scintillation light signals for triggering and reconstruction purposes with minimal impact to the overall target volume. ArCLight is a small-volume, sizeable sensitive-area detector that consists of a light trap covered in a thin layer of TPB that can be placed inside a time projection chamber's electric field. These sensors are used in the Deep Underground Neutrino Experiment Near Detector liquid argon (DUNE ND-LAr). They are constructed and tested at the University of Bern and will be deployed in the prototype experiment ProtoDUNE-ND. The talk discusses the details of assembling ArCLights, the quality control methods, and the test studies done with LEDs to assess their performance.

A long-term irradiation and longevity test was conducted on two bulk-Micromegas detectors with screen-printed resistive strips, working with Ar:CO₂ gas mixture at the CERN GIF++ facility between 2015 and 2018. The results of the test, for a total integrated charge of about 0.3 C/cm², have been recently published.

One of the detectors exposed at GIF++ was then irradiated with X-rays from Cu, this time with an Ar:CO₂:iC₄H₁₀ mixture to study the effect of hydrocarbons like isobutane to the detector longevity. The resistive Micromegas under test has accumulated a total charge of 1.5 C/cm². A second detector with identical construction and characteristics, operated at the same voltages and with the same gas but not irradiated, has been used as reference chamber. Charge spectra with an ⁵⁵Fe source were acquired at regular intervals for both detectors to monitor the evolution of the gain and energy resolution. The accelerated ageing test has been subsequently repeated with the same detector operated with hydrocarbon-free Ar:CO₂ mixture. The paper describes the experimental setup and test procedure, and focuses on the main results and their interpretation.

Versatility of micro-pattern gaseous detectors (MPGD) make them suitable for the use in various fields of study, e.g. nuclear physics, particle physics, dark matter physics along with a wide range of medical and security applications. Our primary interest was to implement the novel μ-RWELL (micro-Resistive WELL) detector as the gas amplification stage in TACTIC, a cylindrical active target time projection chamber (TPC) designed to study nuclear reactions with astrophysical significance. In preparation towards their installation inside TACTIC, the performance and characteristics of μ-RWELL were studied in a test chamber, a planar analogue of TACTIC. This work reports the high gas gains achieved in Ar:CH₄ and He:CO₂ and a study of the charging-up effect in He:CO₂.

The Los Alamos Neutron Science Center (LANSCE) H^- ion source has provided stable output for decades of LANL mission needs, but its maximum beam output has remained the same at ∼15 mA. A roadblock to improving beam output has been a lack of thorough understanding of the internal mechanisms of LANSCE H^- ion source. The LANSCE H^- Ion Source Laser Diagnostic Stand (HLDS) was recently built and commissioned to explore these internal mechanisms using laser absorption techniques, to measure and diagnose dynamic H^- and cesium densities. The cesium density probe is based on resonant absorption of a continuous wave diode laser tuned though the D₂ line of cesium (∼852 nm). The diagnostic capabilities of HLDS will be reviewed, and measurements using the cesium laser diagnostic will be presented.

A prototype of the WEM (Well Electron Multiplier) detector with an active area of 10 × 10 mm² and a resistive DLC anode was tested in terms of robustness to electrical discharges induced by highly ionizing particles (²⁴¹Am alpha source). The perforated structure of the WEM detector was produced from a 500 μm thick FR4 with drilled holes of 200 μm in diameter and 500 μm in pitch. The resistive anode was made of 100 nm thick DLC layer with 30 MOhm/square sheet resistance deposited on the anode grid electrode. The anode grid electrode is used to distribute voltage to the resistive layer and provide fast charge evacuation. The detector was operated in Ar:CO₂ (90:10) gas mixture at gas gain of 3,500. The alpha source was placed in the drift gap. The WEM detector with intrinsic capacitance of 34 pF did not show visible damage and changes in performance after 1 million accumulated discharges. To simulate a large area detector, we added a capacitance up to 1 nF in parallel with the test device. The results of the experiments with an additional capacitance revealed that a small WEM prototype can't be directly scaled to the dimensions more than 60 × 60 mm² without losing the robustness to discharges. We assume that the observed damage could be caused by the design features of the prototype. The grid anode electrode with a thickness of 35 μm results in a gap between the perforated FR4 board and the resistive anode board. Simulations of the electric field distribution with Comsol Multiphysics software revealed a significant electric field strength in this gap. This could lead to electric discharge path bypassing the protective resistive DLC layer. A possible solution to this problem could be additional insulation of the anode grid electrode with a coverlay similar to that used in bulk MicroMegas production.

In this paper we present the design of a photon pre-amplifier based on a photo-cathode coated Thick Gas Electron Multiplier (THGEM). Such device is crucial in application where a weak light signal produced in a radiation detector must be amplified so that it can be carried to a photo-detector by means of optical fibres. An example of a device where a light signal must be amplified is a gamma-ray Cherenkov detector for fusion power measurements in magnetic confinement devices. In such application the active part of the detector must be located very close the plasma, typically in a harsh radiation environment where standard photodetectors cannot operate. The photon pre-amplifier allows to increase the signal generated in the active part of the detector so that it can be easily detected by the photodetector located outside the harsh environment. We present the conceptual design of a THGEM based photon pre-amplifier supported by Garfield++ simulations. The device working principle is the following: primary photons impinge on the photo-cathode and extract electrons that are accelerated by the THGEM electric field. Upon collisions with the accelerated electrons, the gas molecules in the pre-amplifier are brought to excited states and de-excite emitting scintillation photons. Since each electron excites multiple gas molecules, the scintillation photons outnumber the primary photons, leading to the amplification. In addition, we present the first observation of measurements of Nitrogen gas scintillation in a THGEM device. We devised an experimental setup consisting of a vacuum chamber containing a THGEM and an alpha particle source. The vacuum chamber is filled with pure nitrogen and is coupled to a photomultiplier tube via a view-port to detect the scintillation photons generated in the THGEM. For sake of simplicity the electrons that induce the scintillation are generated by the ionization track of an alpha particle rather than by the THGEM photo-cathode coating. A good qualitative agreement between simulations and experiment has been found, however no quantitative conclusions can be made due to the lack of N₂ excitation cross sections in the Garfield++ code.

Inductive magnetic sensors are needed for tokamak operation to provide the low-frequency (LF) measurements leading to the equilibrium reconstruction and to monitor the higher frequency (HF) instabilities; the HF magnetic sensors are often also used as a back-up to the LF ones. For the HF inductive magnetic sensors (fluctuation measurements), we need to minimize the self-inductance (L_SELF) provided that the effective area (N A _EFF) remains sufficiently large, typically requiring L_SELF < 100 μH andN A_EFF ∼ 0.01 m². For the LF inductive magnetic sensors (equilibrium reconstruction), the only physics-based design criteria are that of maximizing N A _EFF > 0.10 m², essentially independently of the resulting L _SELF. Due to these rather different measurement specifications, it is quite the common case that different sets of LF and HF inductive magnetic sensors are used, which significantly complicates the R&D activities and the ensuing manufacturing processes.

Starting in 2007, our group at the Swiss Plasma Centre at the Ecole Polytechnique Fédérale de Lausanne (EPFL) has originally developed the Low-Temperature Co-fired Ceramic (LTCC) technology for producing inductive magnetic sensors, this technology being exceptionally suitable for operating temperatures up to ∼1'000C in very harsh environmental conditions. The similarly named High-Temperature (HTCC) technology uses the same processes but different materials, and it is then suitable for operating temperatures up to ∼1'600C. ITER will have about ∼250 such LTCC sensors, of EPFL design and prototyped at the EPFL, but manufactured by a commercial entity to technical specifications lower than those achieved at the EPFL in terms of track width, track separation and overall manufacturing yields.

While state-of-the-art in 2007, the LTCC and HTCC technologies are now at least 20 years old and new processes have been developed for commercial applications, essentially based on different photolithography (PL) techniques. Recent, and already industrialized, advances in microfabrication using PL techniques offer the possibility to create more compact and optimized designs starting from current industrial standards, therefore extremely facilitating the very costly lab-to-fab step of production, namely all the activities that lead from the ideas in the lab to the actual (industrialized) fabrication. Our goal is to continue to push the frontier of magnetic sensors, bring a commercially viable design that can be used in tomorrow's scientific projects, such as nuclear fusion and astronomy/astrophysics (for instance, in the new generations of miniaturized satellites).

The main advantage of the PL techniques is that a much smaller track width (dd1) can be achieved, down from the routine dd1 = 100 μm of the EPFL LTCC sensors (for ITER: dd1 = 400 μm) to dd1 < 10 μm. A smaller dd1 allows to pack more planar winding loops (m) enclosing a larger area over a smaller geometrical surface. Therefore, PL coils can have a lower self-inductance L_SELF ∝ m² while having the same effective area N A_EFF ∝ m compared to coils manufactured by other more common technologies. Therefore, with PL techniques a similar design could be used for both HF and LF applications, the difference simply being the number of stacked-up layers (n) used to make-up the entire sensor.

In this paper we will present the first developments towards the production of inductive magnetic sensors using PL techniques. Whilst providing the possibility of designing better performing and more compact sensors, the introduction of PL techniques in the manufacturing processes for inductive magnetic sensors has uncovered new limitations and obstacles, such as the required vertical track thickness that is poorly suited for the existing deposition techniques, the need for stacking up multiple wafers and the connection between the sensor and the in-vessel cabling.

Many types of detectors, such as cathode strip chambers and some MPGDs, allow us to reconstruct track positions by induced strip charges. There are two main types of algebraic methods for this reconstruction: center of gravity methods and little-known differential methods. General formulas for differential methods are derived. Their performance is compared with the performance of center of gravity methods. It is shown that the differential methods are better than the previously known center of gravity methods, but the improved center of gravity methods provide results similar to the results of differential methods.

The mechanical performance of an undulator has a significant effect on the on-axis magnetic field and thus a directly affect the performance of photon flux and stable operation in a storage ring. During the phase of mechanical design and construction, it becomes important to develop a method to evaluate the effects of magnetic fields caused by mechanical properties. This paper reveals a method to predict the distribution of a magnetic field utilizing the practice that mechanical performance combined with an ideal magnet assembly enables identification whether the magnet array structure is satisfactory. Moreover, the systematic errors expected from the mechanical inspection can be confirmed in the magnetic field measurement data. This scheme could be used to predict the systematic effects and then to apply effective remedies before the entire machine is completed.

Various superconducting detector solenoids for particle physics have been developed in the world. The key technology is the aluminum-stabilized superconductor for almost all the detector magnets in particle physics experiments. The coil fabrication technology is also important and it has advanced along with the conductor technology, such as the inner coil winding technique, indirect cooling, transparent vacuum vessel, quench protection scheme using pure aluminum strips and so on. The detector solenoids design study is in progress for future big projects in Japan and Europe, that is, ILC (International Linear Collider), FCC (Future Circular Collider) and CLIC (Compact LInear Collider), based on the technologies established over many years. The combination of good mechanical properties and keeping a high RRR is a key point for the development of Al-stabilized conductor. The present concern for the detector solenoid development is to have been nearly losing the key technologies and experiences. Nowadays, there are no industrial companies having the capacity to manufacture such aluminum stabilized superconductor. Complementary efforts are seriously required to re-realize and validate the performance required in the future projects in collaboration with worldwide institutes and industries. Some mid-scale physics experiments required detector solenoids wound with not aluminum stabilized conductor but conventional copper stabilized conductor. The specific requirement is to control the magnetic field distribution precisely, and the efforts to realize the requirement are on going with regard to the magnetic field design technology with high precision simulation, coil fabrication technology and so on.

Diamond with extraordinary properties, such as fast response, and extremely high thermal conductivity, is an ideal choice for the next generation radiation detectors. In this paper, a radiation detector based on a single crystal CVD diamond (3 mm × 3 mm × 200 μm) with (100) orientation is proposed to detect α radiation. The detector employs gold films on the diamond as an electrical contact, and the origin-symmetric current-voltage characteristics demonstrated excellent Ohmic contact behavior. At an electric field of 0.4 V/μm, a current dark value of 4 nA was measured. The detector's pulse speed was tested using 5.486 MeV ²⁴¹Am sources. The time response of the detector to α particles is fast, with a rise time of 260 ps, a fall time of 650 ps, and a pulse width of 1.6 ns. These findings indicate that the detector can be used as a sensor for α radiation.

DANTE is a new Digital Pulse Processor (DPP) developed for fluorescence detectors, like Silicon Drift Detectors (SDDs) or High Purity Germanium detectors (HPGe), used in X-ray Fluorescence (XRF) and X-ray Absorption Spectroscopy (XAS) experiments at synchrotron facilities. Its main features are its optimal energy resolution and peak stability for detector count rate values up to 1–2 Mcps, and its enhanced rejection of pile-up events. In this paper, we present the first complete evaluation of DANTE performance in SOLEIL synchrotron facility. DANTE has been tested in laboratory with an X-ray generator source and in different experiments at LUCIA and PUMA beamlines at SOLEIL.

The Middle East Technical University Defocusing Beamline (METU-DBL) is designed to deliver protons with selectable kinetic energies between 15–30 MeV, and proton flux between 10⁶–10¹⁰ protons/cm²/s, on a maximum 21.55 to 15.40 cm target region with a beam uniformity within ±6%, in accordance with the ESA ESCC No. 25100 specification for single event effects (SEEs) tests in the low energy range. The achieved high proton fluences, allow users to test space-grade materials; electronic circuits, ASICs, FPGAs, optical lenses, structural elements, and coating layers for LEO, GEO, and interplanetary missions.

The total received dose on the Device-Under-Test (DUT) from secondary particles created during proton-material interactions at the first beam collimator and the beam dump never exceed 0.1% of the dose from primary protons. The METU-DBL is equiped with several measurement stations and services to the user teams. A secondary measurement station in a rotating drum that can hold multiple samples has been constructed next to the first collimator which provides neutrons for transmission experiments. At the target region, a robotic table is located, which provides mechanical and electrical mounting points to the samples and allows multiple samples to be tested in a row. A modular vacuum box can also be attached on the robotic table for any test that may require a vacuum environment. Power rails on the robotic table provide various outputs for the DUT. For the data acquisition, high-speed networking and a modular industrial PC are available at the target station. The design of the METU-DBL control software enables test users to integrate and optimize the data acquisition and controlling of the DUT.

The beam properties at the target region are measured with the diamond, Timepix3, and fiber scintillator detectors mounted on the robotic table. With diamond and Timepix3 detectors, measurements are taken from the five different points (center and the four corners) of the test area to measure the proton flux and ensure that it is uniform across the full test area. Fiber scintillators on both axes (X and Y) scan the target area to cross-check the beam profile's uniformity. Secondary doses during the irradiation are measured by a Geiger-Müller tube sensitive to electrons and gammas above 0.1 MeV and by a neutron detector located at the entrance of the R&D room. The room cools down relatively fast after any irradiation (<1 hour).

Accurate linear energy deposition rates and absorbed doses on the samples are calculated using MCNP6, FLUKA and Geant4 Monte Carlo simulations. Alanine dosimetry measurements that are calibrated against these simulations are also used to estimate the absorbed dose on the sample.

High-resolution imaging of neutron induced particles is required in such methods as neutron radiography. However, the scintillation spots in a neutron-sensitive scintillator have not yet been imaged nor measured for size. We developed a high-resolution, real-time neutron induced particle imaging system for observing these particles' trajectories in a scintillator. The developed system is based on a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera combined with a lithium-containing silver-doped zinc sulfide (Li-ZnS(Ag)) scintillator plate. Neutrons from a californium-252 (²⁵²Cf) source were irradiated to the Li-ZnS(Ag) scintillator and imaged with the system. Using our system, we measured the scintillation spots of the neutron induced particles having different shapes in real time. In some of these measured scintillation spots, those with elliptical shapes were observed due to the trajectories of the particles in the scintillator. The spatial resolution calculated from the widths of the scintillation spots was ∼56 μm. Consequently, the developed imaging system is promising for research on neutron imaging that requires high spatial resolution.

The Large High Altitude Air Shower Observatory (LHAASO) is located in Haizi Mountain, Daocheng County, Sichuan Province, with an average altitude of 4410 m. The Wide Field of view Cherenkov Telescope Array (WFCTA) is one of its three observation arrays. Laser calibration system for WFCTA consists of 2 nitrogen lasers and 1 Nd:YAG laser system. During the operation of WFCTA, the outdoor temperature may dropped from 17 °C to about -30 °C, which will bring serious challenges to the operation of laser calibration system operating in the field. In order to ensure the stable working environment and remote operation of the laser, we have developed the LHAASO-WFCTA laser temperature control, remote control and data monitoring system. The fluctuation of temperature in the box is within 1 °C around the target. The laser temperature control system was officially put into operation in Sept. 2020. In this paper, the design scheme, fabrication scheme, comparison of heat dissipation coefficient and test of temperature control system are introduced. The working data shows that both nitrogen molecule lasers and Nd:YAG laser temperature control system can achieve stable and long-term operation in high-altitude extreme field.

Middle East Technical University Defocusing Beam Line (METU-DBL) performs the Single Event Effects (SEEs) radiation tests with protons in the range of 15 MeV to 30 MeV kinetic energy at Turkish Atomic Energy Authority Proton Accelerator Facility (TENMAK NÜKEN-PAF) for space and nuclear applications. The most critical beam transfer elements in the METU-DBL are three quadrupole magnets, which are used for defocusing the beam like optical lenses. The first two quadrupole magnets were purchased commercially, and the third quadrupole magnet was designed by the METU-DBL project team and manufactured by Sönmez Transformer Inc. in Turkey. Electronic, mechanic and magnetic capability tests of this custom-designed magnet were conducted both at TUBITAK and CERN facilities. After passing the acceptance tests, the magnet was certified by CERN and then installed to METU-DBL as a third quadrupole magnet. In this paper, we present details of the design, production and performed tests of the quadrupole magnet.

This study focuses on the development of a fully digital power supply system (FDPSS) for the Taiwan Light Source (TLS) storage ring corrector magnet, which includes the fully digital correction power supply (FDCPS), digital communication card (DCC), and a virtual operation interface. The DCPS adopts a full-bridge circuit architecture, with the TI TMS320F28335 digital signal processor (DSP) as the core, combined with an 18-bit high-resolution A/D converter and discrete PID algorithm to achieve closed-loop current control, ensuring a stable output current value of the system. The DCC can control eight DCPS modules through an RS485 protocol with a virtual instrument control interface. This new system can replace the analog signal-modulated Bira MCOR30A power supply system, which has been in operation for 25 years in the TLS storage ring and can be upgraded to an FDPSS. This article aims to discuss the design concepts, hardware implementation, and testing of FDCPS and DCC to demonstrate the advantages of full digital control and to achieve the goal of independently researching and developing the prototype of FDPSS. Ultimately, after long-term testing and verification, the system's output current stability is less than ± 20ppm, indicating that this new system has high-precision and high-stability output current characteristics. In this study, upgrading the TLS storage ring corrector magnet power supply system to full digital control significantly improves output current stability and accuracy.

The intensity and energy spatial distributions of collimated laser Compton scattering (LCS) γ-ray beams and of the associated bremsstrahlung beams have been investigated as functions of the electron beam energy, electron beam phase space distribution, laser optics conditions and laser polarization. We show that the beam halo is affected to different extents by variations in the above listed parameters. In the present work, we have used laser Compton scattering simulations performed with the eliLaBr code (https://github.com/dan-mihai-filipescu/eliLaBr) and real LCS and bremsstrahlung γ-ray beams produced at the NewSUBARU synchrotron radiation facility. A 500 μm MiniPIX X-ray camera was used as beamspot monitor in a wide γ-ray beam energy range between 1.73 MeV and 38.1 MeV.

The stability of the beam orbit is essential for a storage ring based light source. An orbit feedback system is usually adopted to help maintain the beam circulating on a reference orbit. The movement and deformation of the Beam Position Monitor (BPM) chambers due to thermal effect can affect the BPM readings. The BPM misreading leads to shift of the reference orbit for the orbit feedback system. The feedback system then corrects the beam to a different closed orbit, resulting in a change in the real beam orbit. Online experiments are carried out to measure the BPM readings dependency on the temperature of BPM chambers in the Hefei Light Source II (HLS-II) storage ring. To improve the beam orbit stability, a compensation system is developed to mitigate the reference orbit shift accordingly. With this compensation system, the stability of the reference orbit is improved to be better than 10 μm in the horizontal plane and 5 μm in the vertical plane. This paper reports our work on the measurement of BPM readings dependency and the development of the reference orbit compensation system for the HLS-II storage ring. The online compensation results are also presented.

Recently, digital gamma spectrometers have replaced analog ones due to their durability, flexibility, and compact size. The main part of the digital gamma spectrometer is the digital pulse processing (DPP) unit. The implementation of the DPP unit using the ARM Cortex-M-based microcontroller units is a recent attractive approach. This originates from their advanced features and low cost. In this paper, we propose an implementation of the DPP unit using the ARM Cortex-M3-based microcontroller unit. The targeted detector with this implementation is the sodium iodide detector. However, this implementation is based on less than 2 MS/s sampling rate, it is guaranteed experimentally to cope with input count rates up to 47 kC/s. This results from our specific proposed methodology for extracting pulse height from the trapezoidal-shaped pulses.

The PandaX dark matter detection project searches for dark matter particles using the technology of dual phase xenon time projection chamber. The low expected rate of the signal events makes the control of backgrounds crucial for the experiment success. In addition to reducing external and internal backgrounds during the construction and operation of the detector, special techniques are employed to suppress the background events during the data analysis. In this article, we demonstrate the use of deep neural networks (DNNs) for suppressing the accidental backgrounds, as an alternative to the boosted-decision-tree method used in previous analysis of PandaX-II. A new data preparation approach is proposed to enhance the stability of the machine learning algorithms to be run and ultimately the sensitivity of the final data analysis.

Laser-plasma accelerators are capable of sustaining accelerating fields of 10–100 GeV/m, 100–1000 times that of conventional technology and the highest fields produced by any of the widely researched advanced accelerator concepts. Laser-plasma accelerators also intrinsically accelerate short particle bunches, several orders of magnitude shorter than that of conventional technology, which leads to reductions in beamstrahlung and, hence, savings in the overall power consumption to reach a desired luminosity. These properties make laser-plasma accelerators a promising accelerator technology for a more compact, less expensive high-energy linear collider providing multi-TeV polarized leptons. In this submission to the Snowmass 2021 Accelerator Frontier, we discuss the motivation for a laser-plasma-accelerator-based linear collider, the status of the field, and potential linear collider concepts up to 15 TeV. We outline the research and development path toward a collider based on laser-plasma accelerator technology, and highlight near-term and mid-term applications of this technology on the collider development path. The required experimental facilities to carry out this research are described. We conclude with community recommendations developed during Snowmass.