Table of contents

The optical module of the KM3NeT neutrino telescope is an innovative multi-faceted large area photodetection module. It contains 31 three-inch photomultiplier tubes in a single 0.44 m diameter pressure-resistant glass sphere. The module is a sensory device also comprising calibration instruments and electronics for power, readout and data acquisition. It is capped with a breakout-box with electronics for connection to an electro-optical cable for power and long-distance communication to the onshore control station. The design of the module was qualified for the first time in the deep sea in 2013. Since then, the technology has been further improved to meet requirements of scalability, cost-effectiveness and high reliability. The module features a sub-nanosecond timing accuracy and a dynamic range allowing the measurement of a single photon up to a cascade of thousands of photons, suited for the measurement of the Cherenkov radiation induced in water by secondary particles from interactions of neutrinos with energies in the range of GeV to PeV. A distributed production model has been implemented for the delivery of more than 6000 modules in the coming few years with an average production rate of more than 100 modules per month. In this paper a review is presented of the design of the multi-PMT KM3NeT optical module with a proven effective background suppression and signal recognition and sensitivity to the incoming direction of photons.

High-resolution multi-channel time-to-digital converters (TDC) is an important tool in many physical experiments. In the HL-2A tokamak device,a real-time double-ring neutron time-of-flight (TOFII) spectrometer system used to measure the neutron energy spectrum requires the TDC to have a measurement accuracy of 100 ps and a number of 90 channels. In the measurement-device-independent quantum key distribution (MDI-QKD) system, multi-channel and high-precision TDC is also one of the key factors affecting the final bit rate. In this paper, we propose the field programmable gate array (FPGA) method to develop the TDC. By using the coarse-fine combined measurement method, we complete the TDC design through the tapped delay line formed by the internal carry chain of the FPGA. Our method achieves a time measurement of 90 channels and a time resolution of 52 ps.

The pulsed magnetic field device for Shenguang-II (SG-II) laser facility was upgraded to obtain stronger magnetic field with longer rising time, and to facilitate single person operation. The upgraded magnetic field device adopts a modular design that allows for easy adjustment of individual component and parallel connection of multiple devices. Both the capacitor bank and the gas switch operate in atmosphere environment, and are no longer sealed in enclosure filled with insulating gas. Combined with plug-and-play design, the installment and operation are simplified markedly. The capacitor bank module can be expanded flexibly up to six times the original device. Besides stronger magnetic field with longer duration, large capacitance also allows the device to be compatible with various forms of magnetic field coils and extend the range of magnetic field parameters. Pulsed magnetic fields of 9.6 T and 12.6 T with >1 μs rising time are generated using double- and triple-turn Cu coils of 12 mm diameter at 30 kV charging voltage, at which the intensity of magnetic field is mainly limited by the yield strength of Cu coils. Using an inductively coupled coil made of higher yield strength material of BeCu, the magnetic field strength is further increased to 32 T with >3 μs rising time at 35 kV charging voltage.

The enhancement of the resolution of pump-probe optical diagnostics for ultrafast processes by compressing the probe pulse duration using the CafCA approach [1] is considered on an example of the BISER soft-X-ray generation [2] with the J-KAREN-P laser [3].

The AMoRE collaboration is preparing for the second phase of the experiment, AMoRE-II, which will exploit a 100 kg of ¹⁰⁰Mo isotopes to search for neutrinoless double beta decay from the isotope. Most of the ¹⁰⁰Mo isotopes will be contained in the lithium molybdate (Li₂MoO₄) crystals, which will act as absorbers of cryogenic calorimeters coupled to MMC (metallic magnetic calorimeter) sensors. The detector array will have a total mass of approximately 200 kg with hundreds of detector modules. Hence, considerable effort has been taken to optimize the lithium molybdate crystal detector in terms of the detector performance and preparation procedure to build many detector modules in a reasonable schedule without compromising the detector performance. We found some critical experimental conditions to improve the energy resolution in a series of test experiments. In this paper, we discuss the effect of surface treatment and thermal link connection in improving the energy resolution from 14–15 keV to below 7 keV at 2.615 MeV, ²⁰⁸Tl gamma line, which is near the Q-value of the decay of ¹⁰⁰Mo, 3.034MeV. We also report the high discrimination power for the separation of alpha particles using the simultaneous scintillation light detection with a test performed in the cryogen-free dilution refrigerator.

Dubna Gas-Filled Recoil Separator (DGFRS-2) is a new facility at the Super Heavy Element Factory which allows us to study the properties of superheavy elements (SHEs) formed in complete fusion reactions in the femtobarn cross-section range. High dispersion and complex magnetic configuration make it difficult to tune the separator and find the optimal current values in the magnetic elements. This work presents a simulation model of the DGFRS-2 based on a GEANT4 toolkit. The main methods of trajectory simulations of heavy ions in gaseous media are discussed and several new processes are implemented in GEANT4. Calculation results agreed well with the data produced in test experiments which allows us to use this model for transmission determination and tuning of the separator in experiments aimed at SHE investigations.

We report on a systematic characterization of microbulk Micromegas readouts in high-pressure Ar+1%iC₄H₁₀ and Ne+2%iC₄H₁₀ mixtures. Experimental data on gain, electron transmission and energy resolution are presented for a wide range of drift and amplification voltages and pressures from 1 bar to 10 bar for the argon mixture and from 5 bar to 10 bar in the neon mixture, in steps of 1 bar. Maximum gains higher than 1.7 × 10³ (1.7 × 10⁴) in the argon (neon) mixture are measured for all pressures, without the significant decrease with pressure typically observed in other amplification structures. A competitive energy resolution at 22.1 keV, but with a slight degradation with pressure, is observed: from 10.8% at 1 bar to 15.6% FWHM at 10 bar in Ar+1%iC₄H₁₀ and from 8.3% at 5 bar to 15.0% FWHM at 10 bar in Ne+2%iC₄H₁₀. The experimental setup, procedure and the results will be presented and discussed in detail. The work is motivated by the TREX-DM experiment, that is operating in the Laboratorio Subterráneo de Canfranc with the mentioned mixtures, although the results may be of interest for other applications of time projection chambers at high pressures.

The use of Panda-type polarization-maintaining (PM) fiber for the localized sensing of high temperatures was analyzed with simulations and experiments up to 900°C. Accuracy and repeatability of the results started to decline above 800°C. Fused silica optical fiber melts at 1700°C, which sets an ultimate limit for measurable temperatures. In practice, optical fiber birefringence restricts the maximum temperature to 1060°C where PM fiber loses its ability to maintain polarization. Three sensor fibers (4, 5 and 10 cm long) were spliced at 45° angles to input/output fibers and calibrated in an oven from room temperature to 850–900°C temperature range. Two superluminescent light-emitting diodes (SLEDs) were coupled together as a broadband light source. Birefringence-induced change of the polarization in the sensor fiber was measured with a polarization splitter and an optical spectrum analyzer (OSA) as a function of the wavelength. Temperature-dependent birefringence generates a sinusoidal reflection spectrum from the input polarization mode to the orthogonal output polarization mode. Temperature changes could be concluded from variations in these spectra. Finally, a small fusion device, NORTH, at DTU, Denmark was successfully used as a testbed to make sure that the sensors can handle transportation and the instrumentation required for vacuum operation and still produce sensible data from a harsh environment.

A new program called SIMSPEC-G has been developed to simulate the interaction of gamma-rays of energies upto 1 MeV with different materials. In this work, 3 different geometries of high purity Ge (HPGe) detectors have been studied: single crystal HPGe, segmented single crystal HPGe and clover geometry composed of four HPGe crystals in clover-leaf arrangement. Contributions of different processes to peak formation have also been examined. The simulated spectrum, for a single crystal of clover, and for 662 keV gamma-ray (from ¹³⁷Cs source) has been compared with experimentally obtained spectrum. The addback factor (gain in full energy peak efficiency due to the addition of the energies of the Compton scattered gamma rays in more than one crystal of a clover HPGe detector) and the hit pattern for a range of gamma-ray energies from the experiment have been excellently reproduced by the simulation leading to its validation. The fraction of total events in which highest or full energy is deposited in the first hit crystal is estimated and the use of this idea to improve angular resolution of a Clover detector has been explored.

In this paper, we study the influence of multiple scattering of a relativistic electron on diffracted transition radiation (DTR), which arises when this particle crosses a single-crystal target in the Bragg scattering geometry. For this case we have obtained the expressions describing the angular density of DTR both with and without allowance for multiple scattering of the relativistic electron in the target. The paper shows that the multiple scattering leads to a significant increase in the DTR angular density at low energies of the electron.

We study a possible calibration technique for the nEXO experiment using a ¹²⁷Xe electron capture source. nEXO is a next-generation search for neutrinoless double beta decay (0νββ) that will use a 5-tonne, monolithic liquid xenon time projection chamber (TPC). The xenon, used both as source and detection medium, will be enriched to 90% in ¹³⁶Xe. To optimize the event reconstruction and energy resolution, calibrations are needed to map the position- and time-dependent detector response. The 36.3 day half-life of ¹²⁷Xe and its small Q-value compared to that of ¹³⁶Xe 0νββ would allow a small activity to be maintained continuously in the detector during normal operations without introducing additional backgrounds, thereby enabling in-situ calibration and monitoring of the detector response. In this work we describe a process for producing the source and preliminary experimental tests. We then use simulations to project the precision with which such a source could calibrate spatial corrections to the light and charge response of the nEXO TPC.

To enhance the understanding of the physics of energetic ions in fusion plasma, a high-temporal resolution neutron flux measurement (HTRNFM) system, which is equipped with a fast-neutron scintillation detector embedded with ZnS:Ag phosphor, has been developed for the HL-2M tokamak. It has a temporal resolution of 10 μs during conventional operations. Its dynamic range is sufficiently wide for neutron flux measurements by adopting the combination use of the scalar mode and the Campbell mode. Based on the Monte Carlo calculations, the applicable count rate ranges of both the scalar mode and the Campbell mode are respectively 0.1–10 Mcps and 10–200 Mcps. The performance validation of the HTRNFM system has been performed by neutron flux measurements in magnetohydrodynamic (MHD) quiet plasmas in the HL-2A tokamak. In another plasma with abundant MHD instabilities, both the continuous neutron flux decreases and the rapid neutron flux decreases caused by different MHD instabilities are observed in a more detailed manner for the first time with the HTRNFM system than with other neutron flux measurement (NFM) systems that have a lower temporal resolution of 1 ms. The HTRNFM system will serve as a powerful diagnostic tool for research on energetic ion confinement quality in the HL-2M tokamak.

Demands on Field-Programmable Gate Array (FPGA) data transport have been increasing over the years as frame sizes and refresh rates increase. As the bandwidths requirements increase the ability to implement data transport protocol layers using "soft" programmable logic becomes harder and start to require harden IP blocks implementation. To reduce the number of physical links and interconnects, it is common for data acquisition systems to require interleaving of streams on the same link (e.g. streaming data and streaming register access). This paper presents a way to leverage existing FPGA harden IP blocks to achieve a robust, low latency 100 Gb/s point-to-point link with minimal programmable logic overhead geared towards the needs of data acquisition systems with interleaved streaming requirements.

The ATLAS detector is set to undergo a substantial upgrade termed the "Phase-II" upgrade during the Long-Shutdown in preparation for the start of operation of the High Luminosity Large Hadron Collider (HL-LHC). This paper describes the development and implementation of the Phase-II upgrade low voltage power supply transformer-coupled buck converter (Brick) test bench. A large scale production of approximately 2048 finger low voltage power supplies, with an identical output voltage, is set to be undertaken in the year 2022. This production will culminate in the complete replacement of the LVPS Brick V7.5.0 currently installed within the Tile Calorimeter. Due to the location of the Bricks within the inner barrel of the TileCal their reliability is of the utmost importance. Therefore, the implementation of performance screening will be implemented and will involve the testing and certification of all Bricks produced. A custom test bench has been developed in order to facilitate the above-mentioned testing. The test bench described herein quantifies and logs the performance of an upgrade Brick allowing for comparison with predefined performance metrics before being approved and subsequently installed on-detector.

This work reports the development status of a software framework for the external Time-Of-Flight wall (eTOF) of the Cooler-storage-ring External-target Experiment (CEE). The framework is implemented on CeeRoot, a FairRoot-based simulation and analysis platform. The chains for eTOF simulation and analysis have been developed and described in this paper. The examination of such a structure is in parallel with the technical design and prototype developments. Simulation has given reasonable evaluations on the coverage, occupancy, rate condition, etc., which validated the system design. The analysis chain has been successfully applied to processing the cosmic test data and has contributed to the validation of the prototype performances. The CEE-eTOF software is a continuously refining framework for practice in real operations.

A new algorithm is presented to discriminate reconstructed hadronic decays of tau leptons (τ_h) that originate from genuine tau leptons in the CMS detector against τ_h candidates that originate from quark or gluon jets, electrons, or muons. The algorithm inputs information from all reconstructed particles in the vicinity of a τ_h candidate and employs a deep neural network with convolutional layers to efficiently process the inputs. This algorithm leads to a significantly improved performance compared with the previously used one. For example, the efficiency for a genuine τ_h to pass the discriminator against jets increases by 10–30% for a given efficiency for quark and gluon jets. Furthermore, a more efficient τ_h reconstruction is introduced that incorporates additional hadronic decay modes. The superior performance of the new algorithm to discriminate against jets, electrons, and muons and the improved τ_h reconstruction method are validated with LHC proton-proton collision data at √s = 13 TeV.

We present the facilities of the Aragats Space Environmental Center in Armenia used during multi-year observations of the thunderstorm ground enhancements (TGEs) and corresponding environmental parameters. We analyze the characteristics of the detectors, operated on Aragats, and describe the coordinated detection of TGEs by the network of scintillators, field meters, and weather stations. By using a fast synchronized data acquisition system, we reveal correlations of the multivariate data on time scales from nanoseconds to minutes, which allow us to gain insight into the TGE and lightning origin and their interrelations. Also, we demonstrate how different coincidences of multilayered detector operation can select various species of secondary cosmic rays.

The paper is concerned with the parameter study of a new generation of micro-pixel avalanche photodiodes (MAPD) with deeply buried pixel structure, also named silicon photomultipliers (SiPM) or multi-pixel photon counter (MPPC). The new MAPD of type MAPD-3NM was manufactured in the frame of collaboration with Zecotek Company. Measurements were carried out and discussed in terms of the important parameters such as the current-voltage and capacitance-voltage characteristic, gain, the temperature coefficient of breakdown voltage, breakdown voltage, and gamma-ray detection performance using an LFS scintillator. The obtained results showed that the newly developed MAPD-3NM photodiode outperformed the previous generation in most parameters and can be successfully applied in space application, medicine, high-energy physics, and security. New proposals are also discussed, for further improvement of the parameters of the MAPD photodiodes that will be produced in the coming years.

In this paper, a method based on the usage of a smartphone for measuring simultaneously both heartbeat intervals and respiratory intervals is presented. In particular, the commodity accelerometer of a smartphone is used for measuring the seismocardiographic signal generated by heart activity and the acceleration due to breathing movements. The measurement is performed with the subject laying down, placing the smartphone on his/her xiphoid process. Signal processing algorithms are presented in the paper that can produce an accurate estimation of heartbeat and respiratory intervals from the measured acceleration signals. A metrological validation of the heartbeat and respiratory intervals estimates obtained with the proposed method is carried out by comparison with measurements obtained using an electrocardiograph and a spirometer. Two practical examples of applications of the measured quantities are finally reported, that are the measurement of the Heart Rate Variability from heartbeat intervals and of the Respiratory Sinus Arrhythmia from both the heartbeat intervals and the respiratory signal.

A Cosmic Muon Veto (CMV) detector using extruded plastic scintillators is being designed around the mini-Iron Calorimeter (mini-ICAL) detector at the transit campus of the India based Neutrino Observatory, Madurai for the feasibility study of shallow depth underground experiments. The scintillation signals that are produced in the plastic due to muon trajectories are absorbed by wavelength shifting (WLS) fibres. The WLS fibres re-emit photons of longer wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs detect these photons, producing electronic signals. The CMV detector will use more than 700 scintillators to cover the mini-ICAL detector and will require around 3000 SiPMs. The design goal for the cosmic muon veto efficiency of the CMV is >99.99%. Hence, every SiPM used in the detector needs to be tested and characterised to satisfy the design goal of CMV. A mass testing system was developed for the measurement of gain and choice of the overvoltage (V_ov) of each SiPMs using an LED driver. The V_ov is obtained by studying the noise rate, the gain of the SiPM. This paper describes the experimental setup used to test the SiPMs characteristics along with detailed studies of those characteristics as a function of temperature.

Understanding propagation of scintillation light is critical for maximizing the discovery potential of next-generation liquid xenon detectors that use dual-phase time projection chamber technology. This work describes a detailed optical simulation of the DARWIN detector implemented using Chroma, a GPU-based photon tracking framework. To evaluate the framework and to explore ways of maximizing efficiency and minimizing the time of light collection, we simulate several variations of the conventional detector design. Results of these selected studies are presented. More generally, we conclude that the approach used in this work allows one to investigate alternative designs faster and in more detail than using conventional Geant4 optical simulations, making it an attractive tool to guide the development of the ultimate liquid xenon observatory.

The CALICE Semi-Digital Hadronic CALorimeter (SDHCAL) is the first technological prototype in a family of high-granularity calorimeters developed by the CALICE Collaboration to equip the experiments of future lepton colliders. The SDHCAL is a sampling calorimeter using stainless steel for absorber and Glass Resistive Plate Chambers (GRPC) as a sensitive medium. The GRPC are read out by 1 cm× 1 cm pickup pads combined to a multi-electronics. The prototype was exposed to hadron beams in both the CERN PS and the SPS beamlines in 2015 allowing the test of the SDHCAL in a large energy range from 3 GeV to 80 GeV. After introducing the method used to select the hadrons of our data and reject the muon and electron contamination, we present the energy reconstruction approach that we apply to the data collected from both beamlines and we discuss the response linearity and the energy resolution of the SDHCAL. The results obtained in the two beamlines confirm the excellent SDHCAL performance observed with the data collected with the same prototype in the SPS beamline in 2012. They also show the stability of the SDHCAL in different beam conditions and different time periods.

Ionization electron diffusion in Liquid Argon Time Projection Chambers (LArTPCs) has typically been considered at the detector design stage, but little attention has been given to its effects on calibration and particle identification. We use a GEANT4-based simulation to study how diffusion impacts these techniques, and give consideration to how this effect is simulated. We find that diffusion can cause a drift-dependent bias to both the median and Most Probable Value (MPV) of dQ/dx distributions. The bias is estimated to be ∼ 2.5% (median) and ∼ 5.0% (MPV) for typical maximum drift times in currently running LArTPCs before adding detector specific considerations such as electric field non-uniformities. This indicates that these metrics should not be used for calibration without care, contrary to the conventional wisdom. The impact of diffusion on the ability of LArTPCs to separate muons and protons is small, and not expected to pose any problems in future detectors. Diffusion may however be a significant source of systematic uncertainty when separating particles of more similar masses (muons and pions, kaons and protons). Separation of such populations may be improved by implementation of a drift-time dependent particle identification.

With the evolution of digital technology, the digital demodulation method has become widely employed in near-infrared (NIR) spectrometers due to its advantages of reducing the volume, enhancing the reliability, and increasing the flexibility of instruments. However, digital demodulation has a lower signal-to-noise ratio (SNR), which can be improved by lowering the measurement precision, speed, and stability. To improve the SNR without sacrificing the measurement speed or stability, an improved digital demodulation method was developed based on multichannel combined acquisition. To validate the proposed method, a multichannel combined acquisition digital lock-in amplifier demodulation system was designed for portable raster scanning NIR spectrometers. In this system, six ADC channels were used in conjunction to acquire the modulated sampling signal. Afterwards, comparative experiments were conducted to compare the conventional and novel methods. The experimental results revealed that the SNR increased from 2499 to 3007 with a measurement time of 16.75 s and 17.08 s, respectively. Furthermore, scanning the reference reflector resulted in a baseline drift of 0.064% and 0.060% with a scanning time of 128.27 s and 128.21 s. Scanning the kaolin sample resulted in a baseline drift of 0.27% and 0.23% with a scanning time of 128.44 s and 128.53 s. In brief, the multichannel combined acquisition method can improve the SNR of spectrometers without compromising their stability or measurement time.

Hypothetical short-range interactions could be detected by measuring the wavefunctions of gravitationally bound ultracold neutrons (UCNs) on a mirror in the Earth's gravitational field. Searches for them with higher sensitivity require detectors with higher spatial resolution. We developed and have been improving an UCN detector with a high spatial resolution, which consists of a Si substrate, a thin converter layer including ^10B_4C, and a layer of fine-grained nuclear emulsion. Its resolution was estimated to be less than 100 nm by fitting tracks of either ^7Li nuclei or α-particles, which were created when neutrons interacted with the ^10B_4C layer. For actual measurements of the spatial distributions, the following two improvements were made. The first improvement was to establish a method to align microscopic images with high accuracy within a wide region of 65 mm × 0.2 mm. We created reference marks of 1 μm and 5 μm diameter with an interval of 50 μm and 500 μm, respectively, on the Si substrate by electron beam lithography and realized a position accuracy of less than 30 nm. The second improvement was to build a holder for the detector that could maintain the atmospheric pressure around the nuclear emulsion to utilize it under a vacuum during exposure to UCNs. The intrinsic resolution of the improved detector was estimated to be better than 0.56(8) μm by evaluating the blur of a transmission image of a gadolinium grating taken by cold neutrons. The evaluation included the precision of the gadolinium grating. A test exposure was conducted to obtain the spatial distribution of UCNs in the quantized states on a mirror in the Earth's gravitational field. The distribution was obtained, fitted with the theoretical curve, and turned out to be reasonable for UCNs in quantized states when we considered a blurring of 6.9 μm. The blurring was well explained as a result of neutron refraction due to the large surface roughness on the upstream side of the Si substrate. By using a double-side-polished Si substrate, a resolution of less than 0.56 μm is expected to be achieved for UCNs.

The performance of the ring-imaging Cherenkov detectors at the LHCb experiment is determined during the LHC Run 2 period between 2015 and 2018. The stability of the Cherenkov angle resolution and number of detected photons with time and running conditions is measured. The particle identification performance is evaluated with data and found to satisfy the requirements of the physics programme.

A lot of advancement in the field of semiconductors has made it possible to design a solid state neutron detector. They are small in size and compact, have economical bulk fabrications, require low power for their operation. Hence it can act as a plausible alternative to traditional neutron detector such as gas filled and scintillation detectors. It has been observed that many factors like the choice of converter material, LLD settings and geometrical configurations have an impact on the thermal neutron detection efficiency of solid state neutron detector design. Therefore in the present research work, a systematic GEANT4 simulation have been performed on estimating the simulated thermal neutron detection efficiency (η) for five different solid state detector geometrical configurations design with Boron Carbide (¹⁰B₄C) as a converter material. These detectors geometry configurations designs are planar, rectangular parallel trenches, cylindrical perforation, stack and spherical (single and multi-layer). The objective of the simulations was to obtain critical geometrical features for which the efficiency reaches the maximum value, of the given detector configurations. The influence of the different enrichment levels of ¹⁰B (20% to 80%) in Boron Carbide and different Low-Level Discriminator (LLD) value setting (from 100 keV to 700 keV) on the simulated thermal neutron detection efficiency was also investigated. Finally, the simulated multi channel analyzer spectra or in other words histoplots were obtained for all the detector configurations.

With the increasing application of nuclear technology in many fields, in order to meet the requirements for the measurement range of nuclear radiation dose rate in different fields, a new X/γ dose rate measurement method is proposed in this paper. Using MPPC to couple CsI(TI) scintillator, combined with continuous periodic charges integration electronics, a detector system was developed. It enables MPPC to work in two different regions, avalanche and proportional, and realizes a wide range of dose rate measurement through gain changes between different regions. In experiments, this method measured the γ radiation dose rate in radiation fields between 0.1 μGy/h to 400 Gy/h ⁶⁰Co. Additionally, it measured an energy resolution for ¹³⁷Cs at 9.4% at a dose rate of 1 mGy/h. These results demonstrate that this method is both accurate and feasible.

The SuperCDMS SNOLAB dark matter search experiment aims to be sensitive to energy depositions down to (1 eV). This imposes requirements on the resolution, signal efficiency, and noise rejection of the trigger system. To accomplish this, the SuperCDMS level-1 trigger system is implemented in an FPGA on a custom PCB. A time-domain optimal filter algorithm realized as a finite impulse response filter provides a baseline resolution of 0.38 times the standard deviation of the noise, σ_n, and a 99.9% trigger efficiency for signal amplitudes of 1.1 σ_n in typical noise conditions. Embedded in a modular architecture, flexible trigger logic enables reliable triggering and vetoing in a dead-time-free manner for a variety of purposes and run conditions. The trigger architecture and performance are detailed in this article.

Most measurements in particle and nuclear physics use matrix-based unfolding algorithms to correct for detector effects. In nearly all cases, the observable is defined analogously at the particle and detector level. We point out that while the particle-level observable needs to be physically motivated to link with theory, the detector-level need not be and can be optimized. We show that using deep learning to define detector-level observables has the capability to improve the measurement when combined with standard unfolding methods.

The Resistive Plate Chamber (RPC) is a parallel plate avalanche type particle detector which uses a gas mixture as its active detection medium. While high resistivity materials like glass or bakelite plates are commonly used as the detector electrodes, plastic core-based and metal foil laminated pickup panels with segmented strips are used to readout the induced signals. Large area RPCs (of dimension 2 m× 2 m) of this design are chosen as the active detector elements for the India-based Neutrino Observatory's (INO) magnetised Iron Calorimeter (ICAL) detector. One of the main goals of the ICAL detector is a precision measurement of neutrino oscillation parameters. As part of the ongoing detector R&D, a pad-based — instead of strip-based readout — scheme is being developed to improve localization of particle hit positions, while retaining good charge profile and noise rate characteristics of the strip-based RPC based detectors.

Pulse shape discrimination with pure CsI scintillators is investigated as a method for separating energy deposits by energetic neutrons and photons at particle physics experiments. Using neutron data collected near the European XFEL XS1 beam window the pulse shape discrimination capabilities of pure CsI are studied and compared to CsI(Tl) using near-identical detector setups, which were operated in parallel. The inelastic interactions of 100 MeV neutrons are observed to produce a slower scintillation emission in pure CsI relative to energy deposits from cosmic muons. By employing a charge-ratio method for pulse shape characterization, pulse shape discrimination with pure CsI is shown to be effective for identifying energy deposits from neutrons vs. cosmic muons, however, pure CsI was not able resolve the specific type of neutron inelastic interactions as can be done with CsI(Tl). Using pulse shape discrimination, the rate of energetic neutron interactions in a pure CsI detector is measured as a function of time and shown to be correlated with the European XFEL beam power. The results demonstrate that pulse shape discrimination with pure CsI has significant potential to improve electromagnetic vs. hadronic shower identification at future particle physics experiments.

A characterisation of the Timepix4 pixel front-end with a strong focus on timing performance is presented. Externally generated test pulses were used to probe the per-pixel time-to-digital converter (TDC) and measure the time-bin sizes by precisely controlling the test-pulse arrival time in steps of 10 ps. The results indicate that the TDC can achieve a time resolution of 60 ps, provided that a calibration is performed to compensate for frequency variation in the voltage controlled oscillators of the pixel TDCs. The internal clock distribution system of Timepix4 was used to control the arrival time of internally generated analog test pulses in steps of about 20 ps. The analog test pulse mechanism injects a controlled amount of charge directly into the analog front-end (AFE) of the pixel, and was used to measure the time resolution as a function of signal charge, independently of the TDC. It was shown that for the default configuration, the AFE time resolution in the hole-collecting mode is limited to 105 ps. However, this can be improved up to about 60 ps by increasing the preamplifier bias-current at the cost of increased power dissipation. For the electron-collecting mode, an AFE time resolution of 47 ps was measured for a bare Timepix4 device at a signal charge of 21 ke. It was observed that additional input capacitance from a bonded sensor reduces this figure to 62 ps.

In this paper, a detailed investigation has been carried out to understand the physics behind GEM charging-up and its effects on gain. Experiments have been performed on both double and triple GEM with the help of ⁵⁵Fe X-ray source and a comparative study of these configurations along with the single GEM results observed in our previous work has been reported. The increase in gain due to polarization of GEM foil dielectric and reduction in gain due to charge accumulation on dielectric are studied for various field configurations and different radiation intensities.

Recent advances in segmented solid-state detector arrays for rare-event searches have allowed the technology to approach the ton-scale in detector mass and the scale of meters in size. Often focused around searches for neutrinoless double-beta decay or direct dark matter detection, such experiments also have the capability to search for exotic particles that leave track-like signatures across their volume. However, the segmented nature of such detector arrays often sets the spatial resolution and makes the problem of reconstructing track-like paths non-trivial. In this paper, we present an algorithm that improves reconstruction of track-like events in segmented detectors using multi-objective optimization — a computational technique that optimizes more than one cost function at a time without specifying a quantitative weighting between them. Such a technique allows the reconstruction of tracks through a detector and the determination of path-lengths through individual elements. When combined with the reconstructed energy depositions in each element this allows for a calculation of the stopping power of track-like particles and opens the door to searches for particles with abnormal stopping power like monopoles or lightly-ionizing particles (LIPs). Results are presented which evaluate the precision of the reconstruction tools as they currently stand against Monte Carlo generated data. The algorithm is presented in the context of the CUORE experiment, but has applications to other segmented calorimeter detectors.

The article presents the design and first test results of the neutron spectrometer with count rate up to 7 × 10⁶ events per second with remote detector based on artificial diamond, intended for use on burning plasma experiments. The spectrometer consists of the broadband low-noise amplifier and the data acquisition and processing unit. The design of the amplifier with characteristic impedance matching of the cable line by the dynamic resistance of the transistor base-emitter junction is considered. The data acquisition and processing unit is realized using a real-time event-processing algorithm based on harmonic data analysis. This algorithm includes effective techniques for detecting and excluding overlaps and suppression of fluctuations in the baseline level corresponding to zero signal.

A simple procedure for designing a highly selective microstrip bandpass filter of second order is presented in this paper. The proposed filter is composed of two principal square open-loop resonators and designed with planar structures on a Roger substrate. It is intended for 5G applications, especially for Sub-6 GHz range frequency [3.5–3.8 GHz]. The suggested band pass filter has a very attractive compact size of 7 mm × 15.46 mm. The performance of this simple miniaturized filter, which is characterized by high selectivity in the band of interest, can be seen from its important characteristics: Adaptation, Transmission and Coupling Coefficients. The electromagnetic simulations and measurement results are in good agreement, which validates the design idea and procedure.

The storage ring of the present Hefei Light Source (HLS) consists of four double-bend achromat lattice cells, each with two straight sections. In this paper, a modified double-double bend achromat (DDBA) lattice is proposed for an ultra-low emittance design of HLS, where the circumference of the storage ring and the lengths of all straight sections remain the same. Compared to the typical DDBA lattice, this modified lattice can obtain both lower emittance and lower dispersion in the mid-straight section, thus providing higher brightness of insertion device radiation. The natural emittance of the HLS designed with the modified DDBA lattice is 3.9 nm·rad, about one order of magnitude lower than that of the present HLS.

The FCAL collaboration is preparing large-scale prototypes of special calorimeters to be used in the very forward region at future electron-positron colliders for instant luminosity measurement and a precise measurement of integrated luminosity and for assisting beam-tuning. LumiCal is designed as silicon-tungsten sandwich calorimeter with very thin sensor planes to keep the Molière radius small, thus facilitating the measurement of electron showers in the presence of background. Dedicated FE electronics has been developed to match the timing and dynamic range requirements. A partially instrumented prototype was investigated in a 1 to 5 GeV electron beam at the DESY II synchrotron. In the recent beam tests, a multi-plane compact prototype equipped with thin detector planes fully assembled with readout electronics were installed in 1 mm gaps between tungsten plates of one radiation length thickness. High statistics data were used to perform sensor alignment, and to measure the longitudinal and transversal shower development.

The development of a Time Correlated Single Photon Counting (TCSPC) camera with 256 channels has enabled several applications where single photon sensitivity is crucial, such as LiDAR, Fluorescent Lifetime IMaging (FLIM) and quantum information systems. The microchannel plate-based Multi-Anode Photo-Multiplier Tube (MAPMT) is a 16 × 16 array of 1.656 mm pitch pixels with an active anode area of 26.5 × 26.5 mm². Each pixel can time single photons with an accuracy of 60 ps rms at a maximum photon rate of 480 KHz.

The timing electronics are capable of measuring 120 Mcps, producing huge volumes of data for processing, in the region of 10 Gbps per detector. Limitations in algorithmic data analysis techniques are critical for this application, hence this paper demonstrates a machine learning (ML) model which can determine the photon event coordinates with the objective of processing each one photon per 10 μs. The model applies calibrations for the detector and electronics such as amplitude walk, and charge measurement and channel to channel threshold variation. Optimisation of the model is detailed within the paper, including training hyperparameters, the clustering of coincident events and compression of the model through pruning techniques.

The ML model is trained and tested on a simulation of the microchannel plate (MCP) PMT with timing electronics configured for use as a TCSPC camera, utilising charge sharing techniques to further improve the spatial resolution of the detector. Further objectives of the research are to test the model on detector data, allowing assessment on the variance of accuracy between simulated and real data. Beyond this, assessment of the performance of this approach compared to algorithmic approaches and introduction of statistical reasoning of the robustness of the model will be completed.

A monolithic pixel sensor with small collection electrode and partially depleted sensor diode named HVMAPS25 has been implemented in the 180 nm technology of TSI semiconductors. The pixel size is 25 µm × 35 µm. The pixel electronics contains a fast and low power charge sensitive amplifier, a comparator, a threshold tuning DAC and a digital block that measures the arrival time of the hit with 10 bit resolution and the signal amplitude (time over threshold) with 6 bit resolution. A deep p-well has been used for isolation of the pixel electronics from the sensor substrate. The building blocks of the chip, simulations and the measurement results will be presented.

A standard camera for Single Photon Emission Computed Tomography (SPECT) contains 50–100 photomultiplier tubes (PMTs) that occupy at least 50% of its volume. It is shielded by a thick layer of lead which makes it heavy and bulky. Replacing PMTs by silicon photomultipliers (SiPMs) could significantly reduce the weight and size of a SPECT camera. However, the main obstacle is the limited size of SiPMs: even with the largest commercially available SiPM of 6 × 6 mm² a few thousand channels would be needed to fill a camera. As a solution, we propose to use Large Area SiPM Pixels (LASiPs) which are built by summing the currents of several SiPMs into a single output. We developed a LASiP prototype summing 8 SiPMs using the MUSIC ASIC. To test the feasibility of using this solution in SPECT, we built a proof-of-concept micro camera that consisted of four of our LASiP prototypes coupled to a 40 × 40 × 8 mm³ NaI(Tl) crystal. We were able to reconstruct simple images of a ^99mTc capillary with an intrinsic spatial resolution of ∼2 mm and an energy resolution of ∼11.6%. We also simulated the system with Geant4, finding a good agreement with our experimental results. The simulations were extended to a larger camera, aiming to study the impact of pixel size, shape and noise.

LGAD sensors will be employed in the CMS MTD and ATLAS HGTD upgrades to mitigate the high levels of pile-up expected in the High Luminosity phase of the LHC. Over the last several years, much attention has been focused on designing radiation tolerant gain implants to ensure that these sensors survive the expected fluences, (more than 1–2 × 10¹⁵ n_eq/cm²). However, in test beams with protons and a fs-laser, highly irradiated LGADs operated at a high voltage, have been seen to exhibit violent burn-out events that render the sensors inoperable. This paper will focus on the critical electric field and accordingly the bias thresholds to mitigate the risk of Single Event Burnout (SEB).

Tristan10M is a 10-million-pixel large area detector based on the Timepix3 ASIC. The Timepix3 ASIC can work in event driven mode in addition to the standard frame based mode. Thanks to these capabilities of the Timepix3 ASIC, the Tristan detector is ideal for time-resolved experiments. The Tristan 10M detector is organized in a 2 × 5 module matrix, each module being made up of sixteen Timepix3 chips bump-bonded to a monolithic pixelated silicon sensor. In this contribution, we will report on the status of the detector development, and characterization results in terms of threshold equalization, energy calibration, and flat-field correction. A number of initial commissioning experiments have been carried out on the small molecule single crystal diffraction beamline I19 at Diamond light source, which we will also report on here. In particular, X-ray powder diffraction from a standard sample, LaB₆, was performed to evaluate the inter-module alignment based on per-module basis.

In the clinical situation of positron emission tomography (PET) scans, an activity of an approximately few hundred megabecquerels (3.7 MBq/kg) is used for injection. Monitoring and imaging of moving radioisotopes is useful in clinical applications, such as tracer injection and leakage monitoring in PET scan protocols. We have developed a Compton imaging and PET coincidence system to monitor a moving radioisotope using 8 × 8 GAGG crystal arrays coupled to SiPM arrays with dynamic time-over-threshold-based individual readout circuits, and its imaging performance is considered. The measured resolution of PET and Compton imaging is 3.2 mm and approximately 17 degrees for a ²²Na point source. In the experiment, radiotracers with activities from 11.2 MBq to 93.3 MBq moving with speeds from 1 mm/s to 10 mm/s were used for mimicking the blood flow. Both reconstructed images of PET and Compton imaging successfully visualized the movement, except for Compton imaging in the 93.3 MBq case. PET shows better activity-tracking capability and radio-tracer speeds up to 100 MBq. In contrast, Compton imaging has a wider field of view (FOV) to monitor a larger area than the limited FOV in a PET system. We believe that this work can contribute to solutions of various medical problems such as blood flow measurement and extravasation detection.

Spectral distortion due to the charge sharing effect becomes a severe issue in single-photon counting pixel detectors. The HEPS-BPIX4 prototype chip, dedicated for the HEPS in China, implements a novel architecture to mitigate charge sharing and permit spectroscopic imaging with high efficiency. In the architecture, a central pixel communicates with others in a cluster of 3 × 3 pixels. The algorithm simulation showed a charge sharing elimination accuracy better than 90%. The prototype chip has been designed in a 130 nm CMOS technology. The preliminary measurements show a charge gain of 48 mV/ke⁻ and an equivalent noise charge of 150 e⁻ rms. Detailed tests in a 4 × 4 pixel array for the charge sharing are performed using electrical test pulses. The hit allocation in the core four adjacent pixels of the array indicates that effective suppression of charge sharing has been realized.

Particle identification (PID) is one of the main strengths of the ALICE experiment at the LHC. It is a crucial ingredient for detailed studies of the strongly interacting matter formed in ultrarelativistic heavy-ion collisions. ALICE provides PID information via various experimental techniques, allowing for the identification of particles over a broad momentum range (from around 100 MeV/c to around 50 GeV/c). The main challenge is how to combine the information from various detectors effectively. Therefore, PID represents a model classification problem, which can be addressed using Machine Learning (ML) solutions. Moreover, the complexity of the detector and richness of the detection techniques make PID an interesting area of research also for the computer science community. In this work, we show the current status of the ML approach to PID in ALICE. We discuss the preliminary work with the Random Forest approach for the LHC Run 2 and a more advanced solution based on Domain Adaptation Neural Networks, including a proposal for its future implementation within the ALICE computing software for the upcoming LHC Run 3.

In this article a short overview of current micro-pattern gaseous detectors development and applications at Budker Institute of Nuclear Physics is presented. The triple-GEM detector for the Laser Polarimeter facility and the end-cap discs for the upgrade of the CMD-3 detector are considered in more details.

The ATLAS experiment is currently upgrading the first muon station in the high-rapidity region with the construction of new detector structures, named New Small Wheels (NSW), based on large-size multi-gap resistive strip Micromegas (MM) technology and small-strip Thin Gap Chambers (sTGC). The NSW is being installed in the ATLAS underground cavern during the on-going LHC long shutdown 2 to enter operation for run 3. 128 Micromegas quadruplets, each of which provides four measurements of a particle track, are needed to build the two New Small Wheels, covering a total active area of about 1280 m². The construction of all MM modules, carried out in France, Germany, Italy, Russia and Greece, is completed. Their mechanical integration into sectors, and the installation of on-detector services and electronics for the first NSW is also completed, along with all validation and acceptance tests. The preparation of the second NSW is well advanced. The advanced status of the project, in view of the imminent installation of the two NSW in ATLAS by the 2021 is reported. The integration workflow of Micromegas detectors into sectors is described with focus on cosmic rays results of the final validation tests.

India's Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) employs 16 CCD236 Swept Charge Devices (SCDs) similar in structure to Charge Coupled Device (CCD) image sensors. The CCD236 permits X-ray detection over a large surface area, intended to improve low flux performance, with simplified control interfaces and improved warm temperature performance. These devices were the subject of ground testing and performance evaluation before flight. Data that was recently made available by the Indian Space Research Organisation (ISRO) has permitted the analysis of the performance of the CLASS SCDs after over a year of operations around the Moon. Of particular interest is the change in device performance and behaviour during transit and in lunar orbit. Preliminary analysis has indicated that device FWHM, representing the aggregate of different noise sources, has increased in line with predictions based on ground irradiation and testing.

A 4-channel front-end electronics chip in 65 nm CMOS technology (ASD65 nm) for muon drift tube chambers at high background counting rates in the ATLAS detector at High-Luminosity LHC and in future high-energy collider experiments is presented. Each channel of the ASD65 nm chip is a mixed-signal processing circuit consisting of a Charge Sensitive Preamplifier (CSP), a two-stage shaper, and a timing discriminator. The CSP exhibits a peaking time of 11 ns and a sensitivity of 1.1 mV/fC. The peaking time of the full analog chain is 14.6 ns. The minimum signal-to-noise ratio of the channel is 15 dB for the minimum input charge of 5 fC, and it rises to 40.5 dB for the maximum input charge of 100 fC. At the output, the time representation of input signal is provided in both, CMOS level as well as low-voltage-differential-signal. Each channel consumes a current of 10.6 mA from a single 1.2 V supply, and occupies an area of 0.235 mm². The specified performance parameters of the ASD65 nm have been achieved for 60 pF parasitic capacitance of the detector connected the input terminal.

Imaging Cherenkov detectors form the backbone of particle identification (PID) at the future Electron Ion Collider (EIC). Currently all the designs for the first EIC detector proposal use a dual Ring Imaging CHerenkov (dRICH) detector in the hadron endcap, a Detector for Internally Reflected Cherenkov (DIRC) light in the barrel, and a modular RICH (mRICH) in the electron endcap. These detectors involve optical processes with many photons that need to be tracked through complex surfaces at the simulation level, while for reconstruction they rely on pattern recognition of ring images. This proceeding summarizes ongoing efforts and possible applications of AI for imaging Cherenkov detectors at EIC. In particular we will provide the example of the dRICH for the AI-assisted design and of the DIRC for simulation and particle identification from complex patterns and discuss possible advantages of using AI.

CAEN SpA has developed a 19'' rack-mount solution for the readout of ³He/BF₃ tubes. It is a scalable system allowing the user to put together few to hundreds neutron detectors. It is composed of a CAEN R803x high voltage board, CAEN R1443 preamplifier specifically designed to work at best with ³He/BF₃ tubes and CAEN R5560 14-bit 125 MS/s open FPGA digitizer. Thanks to its firmware programmability, this readout system can perform specific filtering to achieve the best charge, timing and position measurements. CAEN provides a DAQ software to remotely manage the system and acquire waveforms, energy, ToF spectra and perform position reconstruction. Moreover, the R5560 offers the possibility to use SCI-Compiler, a block-diagram-based software which allows to easily implement custom pulse processing algorithms in the board FPGA.

Experimental data shows that both ionization charge and scintillation light in LAr depend on the deposited energy density (dE/dx) and electric field ($\mathcal{E}$). Moreover, free ionization charge and scintillation light are anticorrelated, complementary at a given (dE/dx, $\mathcal{E}$) pair. We present LArQL, a phenomenological model that provides the anticorrelation between light and charge and its dependence on the deposited energy as well as on the electric field applied. It modifies the Birks' charge model considering the contribution from the escape electrons at null and low electric fields, and reconciles with Birks' model prediction at higher fields. Deviations from current Birks' model are observed for LArTPCs operating at low $\mathcal{E}$ and for heavily ionizing particles. The LArQL model presents a satisfactory description at dE/dx and field ranges for interacting particles in LArTPCs and fits well the available data. Improvements via data sets compilation and "global" fits are also interesting features of the model.

Measurement of the X-ray spectra of the He-like Ni ions (Ni²⁶⁺) and their dielectronic satellites (Ni²⁵⁺, Ni²⁴⁺, and Ni²³⁺) plays a crucial role in determination of electronic and ion temperature of plasma in the JET device. Because n ⩾ 3 satellites of Ni²⁵⁺ overlap with resonance line of Ni²⁶⁺, it is important to reconstruct the structure of these satellites reliably. It is especially important in the cases when plasma rotation is high which may result in an additional broadening of the resonance line. This work is an attempt to identify possible causes of the additional broadening of the resonance line due to the effect of overlapping the dielectronic satellites with the resonance line of Ni²⁶⁺ and the effect of toroidal plasma rotation shear.

Proton Sound Detectors (ProSDs) sense (at low latency, <1 ms) the thermoacoustic signal generated by the fast energy deposition at the Bragg peak of a proton beam penetrating an energy absorber. ProSDs are especially promising for experimental monitoring of high pulse rate (FLASH) hadron therapy treatments working in-sync with the beam. This paper presents a mixed signal detector, capable of sensing and processing high rate (1k beam shots/sec) ionacoustic signals with low latency (<1 ms). The system was validated by measuring the dose deposition of a 20 MeV proton beam in water, achieving 3.43% precision (±2.75 Gy_RMS) after 50 ms acquisition (77.56 Gy total dose deposition).

This paper describes a low-power all-digital clock generator (ADCG) designed for reading and processing signals from detectors of large physical experiments. The clock generator operates with a reference clock frequency of 10 to 50 MHz and generates an output signal ranging from 400 to 1800 MHz in 10 MHz steps. The clock generator has been approved in 28 nm CMOS technology of TSMC. The power consumption and chip area of the block are 1.5 mW and 80 × 80 μm² correspondingly. A wide range of reference and output frequencies makes this block versatile in application.

This paper presents the experimental test results of the X-ray photon counting detectors based on our pixel readout ASIC. The chip integrates a 64 × 128 array of pixels in the size of 150 µm × 150 µm and each pixel consists of four 12-bit energy windows. Two types of CdTe detectors have been bump bonded to the ASICs and have been tested.

The electronic characteristics of the readout chip were evaluated first by injecting charge through the calibration capacitors. The non-uniformity of the energy thresholds among pixels was measured and then were compensated by tuning the local DACs.

The detector performance was then characterized using X-ray tubes. The energy responses of the detectors were measured using the characteristic X-ray of the target materials. The global energy thresholds were then calibrated with these specific energies of photons. Polarization effects under different photon fluxes were also studied. Preliminary imaging was conducted. The detector response under uniform irradiation was investigated. The spatial uniformity of the detectors was analyzed and the flat field correction was then conducted to improve image quality. CT detailed test results will be discussed in this paper.

Fusion tokamaks (FT) and hybrid fusion-fission reactors (HFFR) present harsh working conditions characterized by intense neutron and gamma fluxes (>10¹² cm⁻² s⁻¹), high working temperatures (up to 600 °C) and corrosive environment. The breeding blanket region (BB) of these plants are resulting very hostile to the detectors used to monitor/measure fundamental nuclear parameters such as neutron/gamma fluxes and energy spectra, and tritium production. Presently no detectors are ready for being hosted in the harsh environment of the BB and R&D activity is needed to develop and test the candidate detectors. Some important lessons can be learned from past activities carried out in the EU and devoted to studying and realizing nuclear detector prototypes for the European Test Blanket Modules (TBM) of ITER. Amongst the other, these studies pointed out the need for intense neutron fields and calibration facilities closely reproducing the expected working environments to be used for reliable testing and calibration of the prototypes.

Accurate simulation by Monte Carlo technique of the proposed detectors allows to mimic and foresee the response and performances of the detectors pointing out several fundamental and critical aspects on the physical response of the detector so helping in understanding the detectors response. This can help in selecting the best performing detector. The selection is based upon a multi-step procedure.

The lesson learned for ITER-TBM can be helpful to study and develop nuclear detectors to be used in HFFR reactors and in next fusion machines like DEMO this because, despite the difference, the ITER-TBMs and the BB of fusion devices and HFFR reactors experience a number of similarities in terms of radiation level, temperature and nuclear quantities to be measured.

In this paper, after discussing the requirements to be fulfilled by the nuclear detectors that must operate in the harsh environments we will discuss an example of detector development by considering the case of a self-power neutron detector (SPND) with chromium emitter studied and developed for ITER-TBM. The detailed Monte Carlo analysis is also reported and the many issues not yet solved are highlighted and the possible follow up to HFFR instrumentation discussed.

We present a comprehensive end-to-end pipeline to classify triggers versus background events in this paper. This pipeline makes online decisions to select signal data and enables the intelligent trigger system for efficient data collection in the Data Acquisition System (DAQ) of the upcoming sPHENIX and future EIC (Electron-Ion Collider) experiments. Starting from the coordinates of pixel hits that are lightened by passing particles in the detector, the pipeline applies three-stage of event processing (hits clustering, track reconstruction, and trigger detection) and labels all processed events with the binary tag of trigger versus background events. The pipeline consists of deterministic algorithms such as clustering pixels to reduce event size, tracking reconstruction to predict candidate edges, and advanced graph neural network-based models for recognizing the entire jet pattern. In particular, we apply the message-passing graph neural network to predict links between hits and reconstruct tracks and a hierarchical pooling algorithm (DiffPool) to make the graph-level trigger detection. We obtain an impressive performance (⩾70% accuracy) for trigger detection with only 3200 neuron weights in the end-to-end pipeline. We deploy the end-to-end pipeline into a field-programmable gate array (FPGA) and accelerate the three stages with speedup factors of 1152, 280, and 21, respectively.

A set of highly integrated read out ASICs with a common digitising and data acquisition back end but different front ends is currently under development at the GSI electronics department. The concept consists in using an analogue transient recorder stage for an efficient application of the area and power consuming analogue to digital converter. A focus of these ASICs is the read out of detectors with a large dynamic range. Possible applications could be the electromagnetic calorimeter of the PANDA detector or the GEM TPC of the Super-FRS at FAIR.

The NPA based diagnostic complex in ITER consists of four diagnostics: the neutral particle analyzers, the diamond neutral particle spectrometer, the gamma-ray spectrometer, and the neutron spectrometer. The diagnostics are located in equatorial port #11 and share the same vacuum channel. The present paper considers the physical basis of the diagnostic complex and its measurement capabilities in ITER. In addition, the design of the complex and the engineering solutions implemented to meet the ITER requirements are described.

Developing an ultra-high sensitivity electrostatic collection radon monitor benefits the scientific experiments of China Jinping Underground Laboratory. Here, a one cubic meter electrostatic collection vessel with a multi-layer hemispherical metal grid was designed to increase the collection efficiency of positively charged Po-218 ions. The 3D model of the giant electrostatic collection vessel was constructed using the COMSOL Multiphysics simulation software, and the potential and electric field distributions in the vessel were simulated. Numerical simulation results were obtained according to the different radii and voltages applied to the grid. The electric field between the vessel wall and grid, between two grids, and between the grid and surface of the PIPS detector must be set uniformly to reduce the collection time of the positively charged Po-218 ions. Simulation results showed that setting a charged metal grid in the vessel can optimize the electric field distribution, and setting a two-layer charged metal grid in the giant vessel can further increase the cost performance. The average collection times of the electrostatic collection vessel with the two-layer grid along the vertical and oblique lines approximately 15% and 13% of that without the grid. The rates of positively charged Po-218 ions that could pass through the one and two-layer metal grids were 86.78% and 50%. Optimizing the electric field can greatly increase the sensitivity of radon monitors and reduce the humidity restrictions.

Because of a strong demand for circularly polarized radiation, elliptically polarized undulators (EPU) are widely used in synchrotron light source nowadays. At Taiwan Photon Source (TPS) with a 3-GeV ring, the EPU plays an important role to fulfill the needs of the user community for EUV to soft X-ray. Up to phase II, in total five EPU have been installed. Because multiple operating modes are necessary, the EPU suffers changes in attractive and repulsive forces in three directions, in contrast to a general ID, which suffers only a vertical attraction. A mechanical structure of the EPU is required that can withstand multiple stresses and eliminate mechanical deformation. In addition, the EPU, a purely magnetic structure, is sensitive to high-permeability material, which makes the overall structure a heterogeneous material, resulting in a problem with uneven thermal expansion and contraction because of changes in ambient temperature. Here we discuss and propose solutions to resist force and temperature variations of EPU mechanical structures, which includes mechanical simulation and inspection.

This paper presents the design of a high isolation miniaturized compact diplexer model based on Band-Pass Filter technique, which is intended especially for a lower band [1.7 GHz to 1.9 GHz] fixed for 4G-LTE and a higher band [3.4 GHz to 3.8 GHz] fixed for 5G Sub-6 GHz. The designed diplexer is very compact with an overall size of 11× 36.49 mm². The proposed design method is implemented by directly combining two band pass filters (BPFs) with separated electric and magnetic coupling distribution and designed with planar structures on a Rogers RT/duroid 6010LM substrate with a relative dielectric constant of 10.2, which simplifies significantly the design process of diplexer. The performance of this structure is presented and discussed in terms of its important characteristics: Impedance matching, Transmission losses and Isolation. Good agreements between simulated and measured results are achieved, which successfully verifies the proposed design method.

We present a liquid nitrogen (LN₂) cooling station for the high-purity germanium (HPGe) segmented clover detectors of the ELI-NP Array of DEtectors (ELIADE) spectrometer, including its associated filling control and monitoring systems, all designed and built in-house at Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Măgurele, Romania. The automated LN₂ filling process is controlled by a CompactRIO (cRIO) system from National Instruments through a custom LabVIEW software used for monitoring both the internal germanium crystal temperatures as well as the temperatures of external Pt100 sensors (used for detection of overflow of LN₂ from detectors during a filling process). The detectors are filled with LN₂ by opening their individual filling valves (which are mounted on the cooling station) and the process is automatically stopped once an overflow condition is fulfilled by the corresponding external Pt100 sensor located downstream. A twelve-hour cycle is used to periodically fill all of the detector dewars and keep their germanium crystals cool at all times. The associated Graphic User Interface (GUI), Command Line Interface (CLI) and Text User Interface (TUI) are used for both controlling and monitoring the above mentioned process. Alert and warning email messages were also enabled via the cRIO system so that users can be alerted in real-time in the event of any cooling malfunction. In this way, any issues related to the cyclic filling procedure, as well as any abnormal observations regarding the germanium crystal temperatures can be quickly and efficiently addressed before the detectors have a chance to warm back up to room temperature. Temperature data of all the Pt100 sensors corresponding to detectors as well as to the solenoid valves are made available in an influx database by the cRIO control system. The web application Grafana access the database and plots them in real-time for online monitoring.

To enable neutron time-of-flight (TOF) experiments at the RAON heavy-ion accelerator facility, we propose a single bunch beam selection method by combining a fast chopper and double gap buncher in the low-energy beam transport (LEBT) section. The fast chopper operates with switching times of tens of ns to convert a CW beam into a pulsed beam. Then, the double gap buncher performs bunching to shorten the beam pulse duration to less than one radio frequency quadrupole (RFQ) cycle. Ideally, a single isolated bunch can be achieved after the RFQ. In this study, we discuss the system design of the proposed single bunch selection scheme and present detailed beam dynamics simulations.

The objective of the present work was to develop and validate a computational model of the Beta Secondary Standard type 2 (BSS2) system, with sources, filters and the PTW 23392 extrapolation chamber using MCNPx code. Simulations were performed to calculate the absorbed dose rate to tissue at null depth and 0.07 mm for the ⁸⁵Kr, ⁹⁰Sr/⁹⁰Y and ¹⁴⁷Pm beta radiation sources. The response curve was calculated by computing the energy deposited, at different depths, to the sensitive volume of the chamber. The deviations in the absorbed dose rate obtained using the MCNPx code compared to the calibration certificate data were found to be up to 2 %. Deviations up to 10 % were observed for the transmission factor calculated for all three beta sources. This work describes in detail the main parameters and common issues seeing when modelling an extrapolation chamber and three different beta standard sources.

This paper describes results on R&D of an economical and efficient cryogenic system prototype for future liquid xenon detector. The test module of the prototype has a "coldhead" attached to a copper rod, which is specially designed to transport heat loads to a free-boiling liquid nitrogen bath. The performance of the test module and commercial refrigerators is compared. The module with an optimized copper rod has demonstrated more than 1500 W cooling power at 178 K. The temperature of the "cold head" can be kept stable with an error of 0.02 K, its fluctuation is within 0.1 K.

In this research, a method for acquiring radiation beam profiles was developed. Multiple linear beam scanning using a detection strip was performed in a beam cross section at different angles. The obtained data were then mathematically processed and transformed into the radiation beam profile. The profiles of X-ray and electron beams were obtained experimentally using the proposed method, and are reported herein.

The Central Detector (CD) of Jiangmen Underground Neutrino Observatory (JUNO) has a huge acrylic spherical vessel, which will contain 20000 tons of liquid scintillator, being immersed in pure water, endure about 3 × 10⁷ N of buoyancy. It is composed of 263 pieces of acrylic spherical panels bonded by the mass polymerization. Acrylic stress is critical to the structural safety of the JUNO CD, and it is required not to be greater than 3.5 MPa. The specialized measurement system for acrylic stress of the JUNO CD has been designed and realized, which supports non-destructive and quantitative measurement. The measurement system was applied to the main acrylic spherical panels without bonding gap first to verify stress level, which met JUNO's requirement. The bonding quality of acrylic spherical panels is critical, and the stress of bonding gap is concerned. The stresses of acrylic bonding gaps were measured using acrylic samples to help study the bonding techniques. The stress optical coefficient of acrylic bonding gap was calibrated and different bonding methods were studied and compared. We found that the objective function of numerical fitting for acrylic bonding gap needs modification when the measured optical path difference is large, which was analyzed and discussed in this article.

The Cherenkov and fluorescence telescopes are used to detect cosmic rays in many large-scale experiments. Certain large-size optical elements, such as quartz glasses with window and filters, are installed in front of cameras as the window to seal the cameras and minimize the impact of the night sky background light. The transmittance of those optical elements in Cherenkov and fluorescence telescopes is therefore vital for the measurement of the number of photons reaching the camera. The uniformity is an important parameter of transmittance at different wavelength over the whole window surface. It is difficult to ensure the uniformity of the window material when it is produced, especially for the size as large as 1 m². The measurement of the uniformity of the transmittance of filters at different positions on the window, and over a large optical spectrum, is not a trivial task and therefore a dedicated system has been developed. The large-size filter transmittance measurement system can measure the spectrum range from 250 nm to 900 nm. A two dimensional motorized device is used to carry the system and the accuracy of the system is up to 0.01 mm. In addition, the measuring system can measure the transmittance at an incident angle ranging from 0° to 44°. The relative standard deviation can be reduced to less than 1% by alternately measuring with and without samples. The transmittance spectra of the neodymium glass standard sheets and quartz glass JGS2, of size 876 mm × 862 mm × 4 mm have been measured with this system and compared. The result of neodymium glass indicates that the system can measure the transmittance spectrum precisely, up to 1% uncertainty. The results of the JGS2 quartz glass demonstrate that our system is capable of measuring the optical parameters of very large sample with a precision at the level of 1% over a wide spectrum range.

Quality assurance (QA) of the source movement is essential for ensuring the safe delivery of high-dose-rate (HDR) brachytherapy. Here, we proposed a simple and effective method for real-time tracking of the source movement in high-dose-rate brachytherapy based on Cherenkov emission imaging. The Cherenkov light emitted from water irradiated by ¹⁹²Ir-source γ-rays was captured using a high-sensitivity video camera. The source positions and dwell intervals were determined from the light images and compared with the preset values. The source dwell times and transit speeds were measured from the time course of the source positions. The brightness profiles were compared with the dose distributions provided by the treatment planning system. The source movements were visualized in real time as a movie of Cherenkov light emissions. The source positional intervals measured from the Cherenkov emission images agreed well to the preset values within 0.3 mm. The source dwell times were comparable to the preset values within 0.2 s, and the transit speeds were similar to those of previous reports. The brightness distributions agreed with the dose distributions within approximately 40%, except near the source center. The proposed Cherenkov method has good potential for tracking the source movement in real time in brachytherapy, as it could enable simultaneous measurements of the source positions, dwell times, and dose distributions.