Table of contents

Cosmic ray muon imaging technology is an effective non-destructive imaging technique. It is currently used to survey the internal structure of large-scale objects such as active volcanoes, pyramids, and some buildings. Additionally, it is used to detect high-Z materials in scenarios such as border security, nuclear reactor monitoring, and container inspection. All applications of cosmic ray muons require a detector to reveal and measure the flux or angular variations of muons. However, detectors may have specific characteristics for each application depending on the detection requirements. Unlike single-point track detectors, we propose using ground array detectors to investigate how ground array detection technology can be used for 3D reconstruction of objects. We use ground array detection technology for simulation studies and apply the Iterative Correction Algorithm (ICA) to reconstruct two-dimensional projections and obtain three-dimensional images of density distribution. We have also addressed the convergence problem and analyzed and optimized some parameters that may affect the detection results. The advantages of using ground arrays include their ability to simultaneously measure the transmittance flux data of muons in different directions, achieve multi-angle detection, and have a large field of view, enabling the collection of sufficient data for more accurate detection results. To verify the feasibility of our new method, we conducted a simple experimental validation on a cylindrical cement building located in the Large High Altitude Air Shower Observatory (LHAASO). By comparing the experimental results with the cement building in the array, we found that their shape structure and density information are basically consistent, demonstrating the effectiveness of our method.

Deuterium-Deuterium (D-D) neutron source, which could be used in both laboratory and outdoors due to its light weight, small volume and low cost, has been widely applied in thermal neutron imaging (TNI) and prompt gamma-ray neutron activation analysis (PGNAA). And the its optimization design is to obtain highly intense thermal neutrons and low dose rate around the facility with light weight and compact volume. In this paper, the genetic algorithm (GA) combined with MCNP6 was applied to globally optimize moderator, reflector, and shielding structures. As a result, the optimized thermal neutron intensity increased by 1.68 times, while the dose rate, weight and volume respectively decreased by 37%, 52%, and 27%, compared with the data based on the current design. This method could be an effective tool for the compact neutron source design.

Recently, a compact torus injection (CTI) system was developed for central fueling on experimental advanced superconducting tokamak (EAST). As impurity generated by the interaction between CTI plasma and the electrode material can dilute the fuel particle, it is important to measure impurity content in CTI and evaluate the effect of impurity on the plasma before the application of CTI to EAST. A vacuum-ultraviolet (VUV) spectrometer that utilizes a concave holographic grating with 1200 groove mm^-1 was developed and installed on EAST-CTI for impurity emission measurement and transport study. The mainly parts of the spectrometer are an entrance slit, a concave holographic grating with 1200 groove mm^-1 and a charge coupled device (CCD). The spectrometer is designed to image the spectra of 50–460 nm by turning the grating. Preliminary experimental results were obtained from the recent EAST-CTI campaign. Impurity line spectra from 50 to 460 nm wavelength range were measured and identified for several impurity species, such as iron, copper, chromium, oxygen, carbon and fluorine. For example, spectra in the intervals of 150 nm to 300 nm contained strong Fe lines. Helium spectra are also measured in the form of He I and He II spectral lines as helium is the main component of the plasma. The results show that the VUV spectrometer is capable of measuring impurity radiations on EAST-CTI and will be a useful tool for impurity behavior study.

The radiation emitted from radon is a critical background in rare event search experiments conducted at the Yemi Underground Laboratory (Yemilab) in Jeongseon, Korea. A Radon Reduction System (RRS) has been developed and installed in Yemilab to reduce radon concentration in the air. The RRS primarily provides a purified air of 50 m³/h to the cleanroom used to assemble crystal detectors in the AMoRE, a neutrinoless double beta decay search experiment. RRS can reduce the radon level by a factor of 300, so a high-sensitivity radon detector was required. A highly sensitive radon detector was constructed using a 70 L chamber with a large PIN photodiode to measure radon concentration in the purified air. The radon detector shows an excellent resolution of 72 keV (FWHM) for 6.003 MeV alphas from ²¹⁸Po decay and a sensitivity down to 23.8 ± 2.1 mBq/m³ with a boil-off N₂ gas sample. The radon concentration level from the RRS measured by the radon detector was below 0.29 Bq/m³ with a reduction factor of about 300.

Cyclotron Radiation Emission Spectroscopy (CRES) is a technique for precision measurement of the energies of charged particles, which is being developed by the Project 8 Collaboration to measure the neutrino mass using tritium beta-decay spectroscopy. Project 8 seeks to use the CRES technique to measure the neutrino mass with a sensitivity of 40 meV, requiring a large supply of tritium atoms stored in a multi-cubic meter detector volume. Antenna arrays are one potential technology compatible with an experiment of this scale, but the capability of an antenna-based CRES experiment to measure the neutrino mass depends on the efficiency of the signal detection algorithms. In this paper, we develop efficiency models for three signal detection algorithms and compare them using simulations from a prototype antenna-based CRES experiment as a case-study. The algorithms include a power threshold, a matched filter template bank, and a neural network based machine learning approach, which are analyzed in terms of their average detection efficiency and relative computational cost. It is found that significant improvements in detection efficiency and, therefore, neutrino mass sensitivity are achievable, with only a moderate increase in computation cost, by utilizing either the matched filter or machine learning approach in place of a power threshold, which is the baseline signal detection algorithm used in previous CRES experiments by Project 8.

Since 2018, the potential for a high-energy neutrino telescope, named the Pacific Ocean Neutrino Experiment (P-ONE), has been thoroughly examined by two pathfinder missions, STRAW and STRAW-b, short for STRAW and STRAW-b. The P-ONE project seeks to install a neutrino detector with a one cubic kilometer volume in the Cascadia Basin's deep marine surroundings, situated near the western shores of Vancouver Island, Canada. To assess the environmental conditions and feasibility of constructing a neutrino detector of that scale, the pathfinder missions, STRAW and STRAW-b, have been deployed at a depth of 2.7 km within the designated site for P-ONE and were connected to the NEPTUNE observatory, operated by Ocean Networks Canada (ONC). While STRAW focused on analyzing the optical properties of water in the Cascadia Basin, STRAW-b employed cameras and spectrometers to investigate the characteristics of bioluminescence in the deep-sea environment. This report introduces the STRAW-b concept, covering its scientific objectives and the instrumentation used. Furthermore, it discusses the design considerations implemented to guarantee a secure and dependable deployment process of STRAW-b. Additionally, it showcases the data collected by battery-powered loggers, which monitored the mechanical stress on the equipment throughout the deployment. The report also offers an overview of STRAW-b's operation, with a specific emphasis on the notable advancements achieved in the data acquisition (DAQ) system and its successful integration with the server infrastructure of ONC.

This study investigates the correlation between the gain, defined as the increase of measured charge generated from the absorption of incident radiation, and the gain measured as the increase of sensor leakage current in Low Gain Avalanche Detectors (LGAD) before and after neutron irradiations. LGADs exhibit high signal-to-noise ratios for minimum ionizing particles and will be used in high-energy physics experiments, mainly related to timing applications. Transient Current Technique (TCT) measurements were conducted with LGADs and PIN diodes. The electric field screening effect, caused by free and trapped carriers, is identified as the main reason for the differences measured in gain determined from the increase in leakage current and collected charge. These effects are more significant in irradiated LGAD sensors. The experimental results confirm expectations, demonstrating a growing spread between the two measured gains with fluence. The study enables the prediction of charge gain from the leakage current measurements, which are easier to conduct.

The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton water Cherenkov neutrino detector installed on the Booster Neutrino Beam (BNB) at Fermilab. Its main physics goals are to perform a measurement of the neutron yield from neutrino-nucleus interactions, as well as a measurement of the charged-current cross section of muon neutrinos. An equally important focus is the research and development of new detector technologies and target media. Specifically, water-based liquid scintillator (WbLS) is of interest as a novel detector medium, as it allows for the simultaneous detection of Cherenkov light and scintillation. This paper presents the deployment of a 366 L WbLS vessel in ANNIE in March 2023 and the subsequent detection of both Cherenkov light and scintillation from the WbLS. This proof-of-concept allows for the future development of reconstruction and particle identification algorithms in ANNIE, as well as dedicated analyses within the WbLS volume, such as the search for neutral-current events and the hadronic scintillation component.

As one of the main detectors for monitoring neutron flux rate in a nuclear reactor, the fission chamber (FC) suffers from issues such as low sensitivity, limited counting rate dynamic range, and system mode switching is cumbersome. This study utilizes the advantages of gas electron multipliers (GEM), which are easy to fabricate in large areas and have high counting rates, to design a novel fission chamber. By conducting Monte Carlo simulations on parameters such as the thickness of the ²³⁵U coating, the drift distance, and the operating electric field strength, a wide-range fission chamber design that combines high sensitivity and a counting rate range based on GEM has been obtained. The simulation results demonstrated that using a GEM detector to build a fission chamber can significantly improve sensitivity and extend the counting rate range. Subsequently we built a proof-of-concept GEM-based fission chamber and tested it with a ⁵⁵Fe low-energy X-ray source and an Am-Be neutron source. The results showed that the proof-of-concept detector had a good signal-to-noise ratio and energy linearity, as well as clear discrimination between alpha background and neutron pulse amplitudes.

Results in this paper present an in-depth study of time resolution for active pixels of the RD50-MPW2 prototype CMOS particle detector. Measurement techniques employed include Backside- and Edge-TCT configurations, in addition to electrons from a  ⁹⁰Sr source. A sample irradiated to 5 · 10¹⁴ n_eq/cm² was used to study the effect of radiation damage. Timing performance was evaluated for the entire pixel matrix and with positional sensitivity within individual pixels as a function of the deposited charge. Time resolution obtained with TCT is seen to be uniform throughout the pixel's central region with approx. 220 ps at 12 ke^- of deposited charge, degrading at the edges and lower values of deposited charge. ⁹⁰Sr measurements show a slightly worse time resolution as a result of delayed events coming from the peripheral areas of the pixel.

SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the pseudo-rapidity region of 7.2 < η < 8.4. The experiment is located 480 m downstream of the ATLAS interaction point, in the TI18 tunnel. The detector is composed of a hybrid system based on an 830 kg target made of tungsten plates, interleaved with emulsion and electronic trackers, also acting as an electromagnetic calorimeter, and followed by a hadronic calorimeter and a muon identification system. The detector is able to distinguish interactions of all three neutrino flavours, which allows probing the physics of heavy flavour production at the LHC in the very forward region. This region is of particular interest for future circular colliders and for very high energy astrophysical neutrino experiments. The detector is also able to search for the scattering of Feebly Interacting Particles. In its first phase, the detector is ready to operate throughout LHC Run 3 and collect a total of 250 fb^-1.

FASER, the ForwArd Search ExpeRiment, is an experiment dedicated to searching for light, extremely weakly-interacting particles at CERN's Large Hadron Collider (LHC). Such particles may be produced in the very forward direction of the LHC's high-energy collisions and then decay to visible particles inside the FASER detector, which is placed 480 m downstream of the ATLAS interaction point, aligned with the beam collisions axis. FASER also includes a sub-detector, FASERν, designed to detect neutrinos produced in the LHC collisions and to study their properties. In this paper, each component of the FASER detector is described in detail, as well as the installation of the experiment system and its commissioning using cosmic-rays collected in September 2021 and during the LHC pilot beam test carried out in October 2021. FASER has successfully started taking LHC collision data in 2022, and will run throughout LHC Run 3.

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software.

Since the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger.

The ATLAS detector is installed in its experimental cavern at Point 1 of the CERN Large Hadron Collider. During Run 2 of the LHC, a luminosity of   = 2 × 10³⁴ cm^-2 s^-1 was routinely achieved at the start of fills, twice the design luminosity. For Run 3, accelerator improvements, notably luminosity levelling, allow sustained running at an instantaneous luminosity of   = 2 × 10³⁴ cm^-2 s^-1, with an average of up to 60 interactions per bunch crossing. The ATLAS detector has been upgraded to recover Run 1 single-lepton trigger thresholds while operating comfortably under Run 3 sustained pileup conditions. A fourth pixel layer 3.3 cm from the beam axis was added before Run 2 to improve vertex reconstruction and b-tagging performance. New Liquid Argon Calorimeter digital trigger electronics, with corresponding upgrades to the Trigger and Data Acquisition system, take advantage of a factor of 10 finer granularity to improve triggering on electrons, photons, taus, and hadronic signatures through increased pileup rejection. The inner muon endcap wheels were replaced by New Small Wheels with Micromegas and small-strip Thin Gap Chamber detectors, providing both precision tracking and Level-1 Muon trigger functionality. Trigger coverage of the inner barrel muon layer near one endcap region was augmented with modules integrating new thin-gap resistive plate chambers and smaller-diameter drift-tube chambers. Tile Calorimeter scintillation counters were added to improve electron energy resolution and background rejection. Upgrades to Minimum Bias Trigger Scintillators and Forward Detectors improve luminosity monitoring and enable total proton-proton cross section, diffractive physics, and heavy ion measurements. These upgrades are all compatible with operation in the much harsher environment anticipated after the High-Luminosity upgrade of the LHC and are the first steps towards preparing ATLAS for the High-Luminosity upgrade of the LHC. This paper describes the Run 3 configuration of the ATLAS detector.

A Large Ion Collider Experiment (ALICE) has been conceived and constructed as a heavy-ion experiment at the LHC. During LHC Runs 1 and 2, it has produced a wide range of physics results using all collision systems available at the LHC. In order to best exploit new physics opportunities opening up with the upgraded LHC and new detector technologies, the experiment has undergone a major upgrade during the LHC Long Shutdown 2 (2019–2022). This comprises the move to continuous readout, the complete overhaul of core detectors, as well as a new online event processing farm with a redesigned online-offline software framework. These improvements will allow to record Pb-Pb collisions at rates up to 50 kHz, while ensuring sensitivity for signals without a triggerable signature.

The Large Hadron Collider (LHC) Long Shutdown 2 (2019–2021), following LHC Run 2, was primarily dedicated to the upgrade of the LHC Injectors but it included also a significant amount of activities aimed at consolidation of the LHC machine components, removal of known limitations and initial upgrades in view of the High-Luminosity LHC (HL-LHC) to favour the intensity ramp-up during Run 3 (2022–2025). An overview of the major modifications to the accelerator and its systems is followed by a summary of the results of the superconducting magnet training campaign to increase the LHC operation energy beyond the maximum value of 6.5 TeV reached during Run 2. The LHC configuration and the scenarios for proton and ion operation for Run 3 are presented considering the expected performance of the upgraded LHC Injectors and the proton beam intensity limitations resulting from the heat load on the cryogenic system due to beam-induced electron cloud and impedance.

The design and the control scheme of beamline control system for Hefei Advanced Light Facility (HALF;Hefei, People's Republic of China) which is under construction is described in this paper.It mainly includes, equipment protection safety, personal protection safety,fast signal interlock and status monitoring and fault diagnosis system. In this control system ,the human presence perception function has been added to the personal protection safety system. Multi-parameter status monitoring of key equipment on beamline station can automatically alarm equipment failures and send relevant personnel timely notifications. At the same time, it can also provide early warning on the health status of key equipment on the beamline. The system not only improves the safety and reliability of beamline control, but also increases the degree of automation and intelligence, reduces the workload of operation and maintenance personnel, and improves operation and maintenance efficiency.

The neutron measurement properties of Rh-SPNDs are greatly affected by their geometric constructions, which needs to be optimized while designing. This effect is reflected in the sensitivities for gamma and neutron detection. However, the influence on gamma sensitivity has not been fully analyzed before, which is of the same importance as neutron sensitivity. Therefore, it is necessary to quantitatively analyze the relationship between detector sensitivity and geometric dimensions. The effect of Rh-SPND structural and material parameters on neutron and gamma sensitivities has been calculated and analyzed through numerical simulations. The research results show that detector sensitivities are strongly depending on the detector size and its emitter shape. Moreover, the detector response to exogenous reactor gamma can be eliminated by optimizing the detector collector size.

The stability of a dark matter detector on the timescale of a few years is a key requirement due to the large exposure needed to achieve a competitive sensitivity. It is especially crucial to enable the detector to potentially detect any annual event rate modulation, an expected dark matter signature. In this work, we present the performance history of the DarkSide-50 dual-phase argon time projection chamber over its almost three-year low-radioactivity argon run. In particular, we focus on the electroluminescence signal that enables sensitivity to sub-keV energy depositions. The stability of the electroluminescence yield is found to be better than 0.5%. Finally, we show the temporal evolution of the observed event rate around the sub-keV region being consistent to the background prediction.

For next-generation neutrinoless double beta decay experiments, extremely low backgrounds are necessary. An understanding of in-situ cosmogenic backgrounds is critical to the design effort. In-situ cosmogenic backgrounds impose a depth requirement and especially impact the choice of host laboratory. Often, simulations are used to understand background effects, and these simulations can have large uncertainties. One way to characterize the systematic uncertainties is to compare unalike simulation programs. In this paper, a suite of neutron simulations with identical geometries and starting parameters have been performed with Geant4 and MCNP, using geometries relevant to the LEGEND-1000 experiment. This study is an important step in gauging the uncertainties of simulations-based estimates. To reduce project risks associated with simulation uncertainties, a novel alternative shield of methane-doped liquid argon is considered in this paper for LEGEND-1000, which could achieve large background reduction without requiring significant modification to the baseline design.

The use of polymer gels in the radiation dosimetry field is rapidly increasing due to the possibility of 3 dimensional (3D) dosimetry. The aim of this study is to produce a new polymer gel with high dose sensitivity. This involved the production of polymer gel compositions containing different percentages of 2-hydroxyethyl methacrylate (HEMA) monomer and Di(ethylene glycol) dimethacrylate (DEGDMA) and 1-Vinyl-2-pyrrolidinone (VP) crosslinkers and these gels were irradiated with radiation dose between 0.5 Gy to 11 Gy, using 6 MV X-ray energy of the medical linear accelerator. The degree of polymerization was assessed by using magnetic resonance imaging (MRI) based on the R₂-dose response. Then, Fourier Transform Infrared Spectroscopy (FTIR) analysis and Scanning Electron Microscope (SEM) images of the gels were taken. Polymer gels consisting of DEGDMA as crosslinker and Tetrakis (Hydroxymethyl) phosphonium chloride (THPC) as antioxidant were found to have a potential for use in radiation therapy dosimeter. The concentration of HEMA showing the most effective dose response was identified as 12 wt%. It was found that HEMA polymer gels containing DEGDMA crosslinker provide a better dose response than HEMA and HEMA-VP normoxic polymer gels.

We present performance studies of the Time-of-Flight (ToF) subdetector of the ATLAS Forward Proton (AFP) detector at the LHC. Efficiencies and resolutions are measured using high-statistics data samples collected at low and moderate pile-up in 2017, the first year when the detectors were installed on both sides of the interaction region. While low efficiencies are observed, of the order of a few percent, the resolutions of the two ToF detectors measured individually are 21 ps and 28 ps, yielding an expected resolution of the longitudinal position of the interaction, z_vtx, in the central ATLAS detector of 5.3 ± 0.6 mm. This is in agreement with the observed width of the distribution of the difference between z_vtx, measured independently by the central ATLAS tracker and by the ToF detector, of 6.0 ± 2.0 mm.

Micro-Pattern Gaseous Detectors (MPGDs) with resistive anode planes provide intrinsic discharge robustness while maintaining good spatial and time resolutions. Typically read out with 1D strips or pad structures, here the characterisation results of resistive anode plane MPGDs with 2D strip readout are presented. A µRWELL prototype is investigated in view of its use as a reference tracking detector in a future gaseous beam telescope. A MicroMegas prototype with a fine-pitch mesh (730 line-pairs-per-inch) is investigated, both for comparison and to profit from the better field uniformity and thus the ability to operate the detector more stable at high gains. Furthermore, the measurements are another application of the RD51 VMM3a/SRS electronics.

Directional detection is the dedicated strategy to demonstrate that DM-like signals measured by direct detectors are indeed produced by DM particles from the galactic halo. The experimental challenge of measuring the direction of DM-induced nuclear recoils with (sub-)millimeter tracks has limited, so far, the maximal directional reach to DM masses around 100 GeV. In this paper, we expose the MIMAC detector to three different neutron fields and we develop a method to reconstruct the direction of the neutron-induced nuclear recoils. We measure an angular resolution better than 16° for proton recoils down to a kinetic energy of 4 keV and for carbon recoils down to a kinetic energy of 5.5 keV. For the first time, a detector achieves the directional measurement of proton and carbon recoils with kinetic energies in the keV range without any restriction on the direction of the incoming particle. This work demonstrates that directional detection is around the corner for probing DM with masses down to  (1 GeV).

Water Cherenov detector is a vital part in most of neutrino or cosmic ray research. As detectors grow in size, the water attenuation length (WAL) becomes increasingly essential for detector performance. It is essential to measure or monitor the WAL. There are two ways to measure WAL, one is to take a water sample from the detector and measure it in the WAL measurement device, and the other is to put the device directly into the water Cherenkov detector. For the device in the water, the Super-Kamiokande experiment achieved WAL measurement capability near 100 meters with a moving light source up and down. A novel system has been proposed to address the challenge of investigating long WAL. This system focuses on ample water Cherenkov detectors and features a fixed light source and photomultiplier tubes (PMTs) at varying distances, eliminating the need for moving parts. Each component, including LED, diffuse ball, PMTs, and fibers, is introduced to explain uncertainty control. Based on lab tests, the measurement uncertainty of each PMT channel has been controlled within 5%. Additionally, camera technology is also used during the evaluation of the system uncertainty, which has the potential to replace PMTs in the future for this measurement. Monte Carlo simulations have shown that the system can achieve a 5% uncertainty at WAL of 80 meters and 8% at WAL of 100 meters. This system can be used in experiments with large Cherenkov detectors such as JUNO-water veto and Hyper-K.

Brain-computer interface (BCI) is an emerging technology which provides a road to control communication and external devices. Electroencephalogram (EEG)-based motor imagery (MI) tasks recognition has important research significance for stroke, disability and others in BCI fields. However, enhancing the classification performance for decoding MI-related EEG signals presents a significant challenge, primarily due to the variability across different subjects and the presence of irrelevant channels. To address this issue, a novel hybrid structure is developed in this study to classify the MI tasks via deep separable convolution network (DSCNN) and bidirectional long short-term memory (BLSTM). First, the collected time-series EEG signals are initially processed into a matrix grid. Subsequently, data segments formed using a sliding window strategy are inputted into proposed DSCNN model for feature extraction (FE) across various dimensions. And, the spatial-temporal features extracted are then fed into the BLSTM network, which further refines vital time-series features to identify five distinct types of MI-related tasks. Ultimately, the evaluation results of our method demonstrate that the developed model achieves a 98.09% accuracy rate on the EEGMMIDB physiological datasets over a 4-second period for MI tasks by adopting full channels, outperforming other existing studies. Besides, the results of the five evaluation indexes of Recall, Precision, Test-auc, and F1-score also achieve 97.76%, 97.98%, 98.63% and 97.86%, respectively. Moreover, a Gradient-class Activation Mapping (GRAD-CAM) visualization technique is adopted to select the vital EEG channels and reduce the irrelevant information. As a result, we also obtained a satisfying outcome of 94.52% accuracy with 36 channels selected using the Grad-CAM approach. Our study not only provides an optimal trade-off between recognition rate and number of channels with half the number of channels reduced, but also it can also advances practical application research in the field of BCI rehabilitation medicine, effectively.

Radiation hard Double Sided Silicon Strip Detectors are used at the Silicon Tracker for the detection of two-dimensional position andenergy measurement of the incident protons in the R3B experiment at FAIR. Double Sided Silicon Strip Detectors were fabricated by Micron Semiconductor Ltd., U.K. and the first set of experimental measurements havebeenperformed on the non-irradiated detectors in order to understand the macroscopic performance of the detectors for the tracker. This study is extended to the performance of the irradiated detectors in the proton radiation environmentusing proton radiation damage model. The detectors were irradiated with 23 MeV protons up to an expected fluence of 8 × 10¹⁴ n_eq cm^-2, which is one order higher than expected fluence at an initial phase0 of the experiment. The performance characteristics of the detectors on the full depletion voltage, leakage current, and charge collection efficiency were extrapolated using SRH and CCE modelling, which is usually implemented in device TCAD. The results on the detectors were compared with the available experimental data on the detectors. A very good comparison between experimental data and calculated resulthave been recorded for non-irradiated and irradiated detectors. The agenda is to propose a proton radiation hard Double Sided Silicon Strip Detector design on the basis of the present study for the phase 1 upgrade of the experiment.

The CMS detector will be upgraded for the HL-LHC to include a MIP Timing Detector (MTD). The MTD will consist of barrel and endcap timing layers, BTL and ETL respectively, providing precision timing of charged particles. The BTL sensors are based on LYSO:Ce scintillation crystals coupled to SiPMs with TOFHIR2 ASICs for the front-end readout. A resolution of 30–60 ps for MIP signals at a rate of 2.5 Mhit/s per channel is expected along the HL-LHC lifetime. We present an overview of the TOFHIR2 requirements and design, simulation results and measurements with TOFHIR2 ASICs. The measurements of TOFHIR2 associated to sensor modules were performed in different test setups using internal test pulses or blue and UV laser pulses emulating the signals expected in the experiment. The measurements show a time resolution of 24 ps initially during Beginning of Operation (BoO) and 58 ps at End of Operation (EoO) conditions, matching well the BTL requirements. We also showed that the time resolution is stable up to the highest expected MIP rate. Extensive radiation tests were performed, both with x-rays and heavy ions, showing that TOFHIR2 is not affected by the radiation environment during the experiment lifetime.

We present a study on the neutron activation of a gamma-ray detector for a BNCT-SPECT dose imaging system. The detector is based on a LaBr₃(Ce+Sr) scintillator crystal, coupled with a matrix of Silicon Photomultipliers (SiPMs), read by a dedicated electronics system. This detector has successfully demonstrated to be capable to identify the ¹⁰B compounds when irradiating borated vials with thermal neutrons. However, a background signal around 478 keV was detected, suggesting the activation of the detector itself. This study aims to determine the origin of this background signal by simulating the two main parts of the detector, which are the crystal and electronic boards, in order to assess their contribution to the background signal. The results of the FLUKA simulations show that the neutron capture reactions on both the crystal and electronic boards cause a relevant background nearby the BNCT signal, thereby limiting the detector's sensitivity. To address this issue, a customized cadmium shielding has been developed. This solution was tested at the TRIGA Mark II research nuclear reactor of Pavia University, where experimental measurements and corresponding FLUKA simulations proved its effectiveness.

The transverse impedance is one of the potentially limiting effects for the performance of the High-Luminosity Large Hadron Collider (HL-LHC). In the current LHC, the impedance is dominated by the resistive-wall contribution of the collimators at typical bunch-spectrum frequencies, and is of broad-band nature. Nevertheless, the fundamental mode of the crab cavities, that are a vital part of the HL-LHC baseline, adds a strong and narrow-band contribution. The resulting coupled-bunch instability, which contains a strong head-tail component, requires dedicated mitigation measures, since the efficiency of the transverse damper is limited against such instabilities, and Landau damping from octupoles would not be sufficient. The efficiency and implications of various mitigation strategies, based on RF feedbacks and optics changes, are discussed, along with first measurements using crab cavity prototypes at the Super Proton Synchrotron (SPS).

As the primary safety protection system for particle accelerators, the Personnel Protection System (PPS) not only prioritizes safety but also recognizes the importance of system reliability to ensure the stable operation of the accelerator and foster trust among system stakeholders. When designing the PPS, a distinction can be made between critical safety functions and common functions. There are at least three critical safety functions: firstly, ensuring that personnel are prohibited from accessing the tunnel during accelerator operation; secondly, preventing accelerator activation in the presence of personnel within the tunnel; and thirdly, enabling prompt termination of accelerator operations during emergency situations. To meet the demanding safety integrity level requirement of SIL3, multiple layers of defense and safety redundancy are employed. In order to mitigate the potential risks arising from human errors, significant emphasis is placed on improving the automation and intelligence of the system. This research focuses on the development of a comprehensive novel system that incorporates multiple defense mechanisms to meet the stringent safety and reliability demands of large particle accelerators represented by High Energy Proton Source (HEPS). It designs novel local optimization schemes, including the semi-redundant control system, zero-count interlock, intelligent search and secure, and electromagnetic control key, among others. These pioneering approaches are seamlessly integrated into the comprehensive system, effectively enhancing its capabilities and overall efficiency. Furthermore, this study conducts an analysis of the reliability of interlocking equipment, employing measures such as hierarchical DC power, parallel redundancy, and optimized signal processing to enhance its overall reliability. Finally, a method for determining the Safety Integrity Level (SIL) and assessing the reliability of PPS is developed, and the system's performance is validated.

Lithium is generally adopted as the target to generate epithermal neutrons based on ⁷Li(p,n)⁷Be nuclear reaction for the application of accelerator-based boron neutron capture therapy (AB-BNCT). The stability of neutron yields and neutron energy spectrum are key factors for the therapeutic effects of the AB-BNCT. Owing to the active chemical properties of lithium, the surface oxidation formation of lithium may influence the soundness of the target system and the stability of neutron yields. Experimental and simulation methods were performed for a better understanding of the passivation layer formation after air exposure and the influence of the passivation layer on the neutron yield and energy spectrum. On one hand, X-ray photoelectron spectroscopy was adopted to study the chemical states of lithium after air exposure. On the other hand, particle and heavy ion transport code system (PHITS) was used to evaluate the effect of surface chemical states variation on neutron yield and energy spectrum. The simulation results indicate that the formation of Li₂O with a thickness of 2 μm could mainly influence the neutron yields at the neutron emission angle of 20–90°  with a maximum reduction of ∼ 10.4%.

To ensure the long-term stability of the beam and further construction needs, it is necessary to re-measure the particle accelerator regularly. Since 2013, we have been measuring the HLS-II control network with laser trackers and the level for 10 years. Taking HLS-II as the object of study, we introduced the data acquisition strategy for the period of 2013–2023. We analyzed the horizontal and vertical deformation trends of each control point. In the vertical direction, we fused the geometric level and elevation data of the laser tracker network by using MC-GMM (a Gauss-Markov model which considers the uncertainty of Monte Carlo simulation). The analysis results show that, after the HLS upgrade, the annual average settlement of the ground control network tends to be stable. The settlement and horizontal variation of the device are all within a reasonable and controllable range. To ensure stability, accuracy, and efficiency in the measurement, we recommend employing the laser tracker for the re-measurement of the HLS-II storage ring. The data processing flow and methods mentioned in the article can provide a reference for deformation analysis of the upcoming construction of the Hefei Advanced Light Facility (HALF) and other large-scale metrology projects.

Acrylic is widely used in aquariums, windows of planes and submarines, and even scientific experiments like the Sudbury Neutrino Observatory (SNO) and the Jiangmen Underground Neutrino Observatory (JUNO). Internal stress has a significant impact on the properties and characteristics of acrylic such as strength, fracture and creep, which is highly concerned and has become a hotspot in research field. The measurement of internal stress is an important issue, which includes two aspects - the calibration of stress-optical coefficient of acrylic and the measurement of birefringence optical path difference (BOPD) caused by internal stress. The measuring equipment mainly realize the measurement of BOPD, and currently have the largest dynamic range of 50–3000 nm. Dynamic range is considered as one of the core performance indicators of measuring equipment, and a larger dynamic range is urgently required to meet the needs of different scenarios. The novel equipment for measuring internal stress in acrylic has been designed and developed based on photo-elastic principle and spectrometric method, which has the dynamic range of 20–12000 nm and the uncertainty of stress measurement better than 3%. The measuring principle, components, functions and measurements of the novel measuring equipment are introduced and discussed in this article.

In this study, a 32-channel front-end data acquisition unit (DAQU) with high temporal resolution and count rate was developed at the Heavy Ion Research Facility in Lanzhou (HIRFL), China, to measure the lifetime of ¹⁰¹Sn on the Spectrometer for Heavy Atoms and Nuclear Structure. The DAQU data analysis module uses a field programmable gate array (FPGA) to implement and time stamp extraction through an FPGA-based tapped delay line (TDL) time-to-digital converter. The energy measurements were implemented using a trapezoidal algorithm and a sliding baseline averaging method. The DAQU was tested and calibrated using a pulse generator and cosmic rays. The results show that the system had a dead time of less than 500 ns, a dynamic range of "0" to "500" mV, and an energy resolution of better than 4.8‰ (full width at the half-maximum, FWHM). In addition, the single-channel temporal resolution under multi-channel settings surpasses 111.2 ps (FWHM), satisfying the experiment's requirements for the electronics system.

Next generation neutrino telescopes are highly anticipated to boost the development of neutrino astronomy. A multi-cubic-kilometer neutrino telescope, TRopIcal DEep-sea Neutrino Telescope (TRIDENT), was proposed to be built in the South China Sea. The detector aims to achieve ∼ 0.1 degree angular resolution for track-like events at energy above 100 TeV by using hybrid digital optical modules, opening new opportunities for neutrino astronomy. In order to measure the water optical properties and marine environment of the proposed TRIDENT site, a pathfinder experiment was conducted, in which a 100-meter-long string consisting of three optical modules was deployed at a depth of 3420 m to perform in-situ measurements. The central module emits light by housing LEDs, whereas the other two modules detect light with two independent and complementary systems: the PMT and the camera systems. By counting the number of detected photons and analyzing the photon arrival time distribution, the PMT system can measure the absorption and scattering lengths of sea water, which serve as the basic inputs for designing the neutrino telescope. In this paper, we present the design concept, calibration and performance of the PMT system in the pathfinder experiment.

To achieve the physics goal of precisely measure the Higgs, Z, W bosons and the top quark, future electron-positron colliders require that their detector system has excellent jet energy resolution. One feasible technical option is the high granular calorimetery based on the particle flow algorithm (PFA). A new high-granularity hadronic calorimeter with glass scintillator tiles (GSHCAL) has been proposed, which focus on the significant improvement of hadronic energy resolution with a notable increase of the energy sampling fraction by using high-density glass scintillator tiles. The minimum ionizing particle (MIP) response of a glass scintillator tile is crucial to the hadronic calorimeter, so a dedicated beamtest setup was developed for testing the first batch of large-size glass scintillators. The maximum MIP response of the first batch of glass scintillator tiles can reach up to 107 p.e./MIP, which essentially meets the design requirements of the CEPC GSHCAL. An optical simulation model of a single glass scintillator tile has been established, and the simulation results are consistent with the beamtest results.

Transition-edge sensors (TESs) are sensitive devices for detecting photons from millimeter radiation to γ rays. Their photon counting efficiency and collecting area benefit from large-array multiplexing scheme, and therefore the development of multiplexing readout system has been an important topic in this field. Among the many multiplex techniques, time-division multiplexing (TDM) superconducting quantum interference device (SQUID) has been used most widely for TES readout. In this work, we design a Configurable Ultra-Low Noise Current Source (CLCS) for TES characterization and as a part of a whole TDM-TES bias control system. The CLCS is based on the feedback structure of ultra-low noise instrumentation amplifiers and low-noise, high-resolution (20 bits) digital-to-analog converter (DAC). CLCS has an ultra-high resolution of 10 nA in the 0 to 5 mA current output range, and can perform current-voltage (IV) sweep and bias-step tests to measure key TES parameters on board. The feedback structure of the CLCS also avoids the issue of impedance mismatch.

In this work, we present new studies by using different materials and procedures to improve the performances and radiopurity of Cs₂ZrCl₆ (CZC) crystal scintillators. In particular, measurements of three new CZC crystals as scintillators were performed over 97.7 days live-time in the low-background DAMA/CRYS set-up deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. They allow us to derive elements for improvements towards a possible future use of this kind of detectors in the search for neutrino-less double beta decay of ^94,96Zr and rare single beta decay of ⁹⁶Zr.

This article deals with the development of real-time air quality monitoring based on Unmanned Aerial Vehicles (UAVs) and low-cost Internet of Things (IoT) devices. This investigation aims to design and develop an UAV-based platform that can monitor a large number of air pollutants in real-time with high spatial and temporal resolution. The proposed environmental monitoring system consists of five main elements, namely the UAV, sensors, data storage module, programmable card, and IoT communication module. Estimated pollutants such as particulate matter (PM_2.5) and toxic gases (carbon monoxide CO, nitrogen dioxide NO₂, and carbon dioxide CO₂) are detected by low-cost sensors. The ZigBee wireless protocol is used for communication between the PC and UAV. This work is carried out to assess the air quality in urban areas, given the heavy road traffic and the emissions of some companies. The data analyzed were collected from December 2, 2022 to January 3, 2023, in two major cities of Cameroon, Douala and Kribi. The periodic average values of the detected pollutants are 222 ± 22 μg/m³  and 85.7 ± 8.6 μg/m³ for PM_2.5, 560.8 ± 1.0 ppm and 555.6 ± 1.0 ppm for CO₂, 4.2 ± 0.2 ppm and 0.7 ± 0.1 ppm for NO₂, and 27.6 ± 2.8 ppm and 4.5 ± 0.5 ppm for CO in Douala and Kribi respectively. This made it possible to have an air quality index (AQI) of 444.2 for Douala City and 171.3 for Kribi City. These high values indicate poor air quality during the measurement period.

Modern neutrino physics detectors often employ thousands, and sometimes even hundreds of thousands, of Silicon Photomultipliers (SiPMs). The TAO experiment [1] is a notable example that utilizes a spherical scintillator barrel with a diameter of 1.8 meters, housing approximately 130,000 SiPMs organized into 4,100 tiles. Each tile with size of 5×5 cm² consists of a 32-SiPM array functioning as a single detector unit. To achieve an unparalleled energy resolution of 2% at 1 MeV within this volume, the SiPMs must possess cutting-edge parameters, including a photon detection efficiency (PDE) exceeding 50%, cross-talk of approximately 10%, and an extremely low dark count rate (DCR) below 50 Hz/mm². Maintaining the setup at a negative temperature of -50°C is necessary to achieve the desired DCR. This article presents the setup and methods employed to individually characterize the mass of SiPMs across all 4,100 tiles at the specified negative temperature.

Recently we have proposed a new concept of a thermal neutron detector based on resistive plate chambers and ¹⁰B₄C solid neutron converters, enabling to readout with high resolution in both the 3D position of neutron capture and the neutron time of flight (ToF). In this paper, we report the results of the first beam tests conducted with a new neutron RPC detection module, coupled to the position readout units of a new design. The main focus is on the measurements of the neutron ToF and identification of the converter layer where the neutron is captured, giving the position along the beam direction.

The coupled structure with ladder radio-frequency quadrupole (RFQ) and interdigital H-type drift tube linac (IH DTL) has been proposed to accelerate the proton beam to several MeV with high acceleration gradient and one RF feed-in system. A ladder RFQ-IH DTL coupled structure was designed to accelerate a proton beam 2.5 MeV with a peak current of 15 mA. Detailed dynamics optimization and error study were performed to achieve high transmission efficiency and small emittance growth, including ladder RFQ, coupling section and IH DTL section. The Kombinierte Null Grad Struktur (KONUS) dynamics scheme with two quadrupole doublets (QDs) was adopted in the IH-DTL section. Start-to-end beam tracking results showed that the proton beam can be accelerated to the final energy with a length of 2.11 m and a transmission efficiency above 98.5%. In addition, we performed error sensitivity analysis and the combined error study to evaluate the error tolerance limits of the ladder RFQ-IH DTL coupled structure.

Boron-lined gaseous neutron detectors intrinsically suffer from the "self-absorption" effect and hence their neutron detection efficiencies might be nonconstant, when the threshold of them undergoes unexpected variation. To address this problem, we propose a maximum likelihood estimation-based threshold determining method, via which the pulse height spectra acquired under different high voltages could be rescaled to the same abscissa axis of deposited energies. Monte Carlo simulations were conducted to study the relationship between the precision of the threshold determination and the counting statistics, as well as the energy deposition spectrum, indicating that the grazing angle incidence neutron detector can achieve a fairly small relative standard variation for a spectrum with a modest total neutron counts. A prototype grazing angle incidence neutron detector has been constructed and tested under high voltages ranging from 500 V to 950 V. The experimental results show that, with the maximum likelihood estimation-based method, the threshold's relative standard deviations are less than 10% even with a total neutron counts as low as 100. As a result, the maximum relative variance of the counting plateau curve is 4.8% in the region of [500 V, 900 V] when the detector operates at a grazing angle of 1.8°. The results presented in this study indicate that combining the grazing angle incidence and the maximum likelihood estimation-based threshold determining method would be a promising way to achieve stable neutron detection efficiency for neutron detectors with the boron layer as the neutron convertor.

The Global Event Processor (GEP) FPGA is an area-constrained, performance-critical element of the Large Hadron Collider's (LHC) ATLAS experiment. It needs to very quickly determine which small fraction of detected events should be retained for further processing, and which other events will be discarded. This system involves a large number of individual processing tasks, brought together within the overall Algorithm Processing Platform (APP), to make filtering decisions at an overall latency of no more than 8ms. Currently, such filtering tasks are hand-coded implementations of standard deterministic signal processing tasks. In this paper we present methods to automatically create machine learning based algorithms for use within the APP framework, and demonstrate several successful such deployments. We leverage existing machine learning to FPGA flows such as hls4ml and fwX to significantly reduce the complexity of algorithm design. These have resulted in implementations of various machine learning algorithms with latencies of 1.2 μs and less than 5% resource utilization on an Xilinx XCVU9P FPGA. Finally, we implement these algorithms into the GEP system and present their actual performance. Our work shows the potential of using machine learning in the GEP for high-energy physics applications. This can significantly improve the performance of the trigger system and enable the ATLAS experiment to collect more data and make more discoveries. The architecture and approach presented in this paper can also be applied to other applications that require real-time processing of large volumes of data.

Photon-counting detector computed tomography (PCD-CT) has demonstrated improvements in conventional image quality compared to energy integrating detector (EID) CT. PCD-CT has the advantage of being able to operate in conventional and spectral mode simultaneously by sorting photons according to selected energy thresholds. However, to reconstruct spectral images PCD-CT requires extensive calibration and specifically fine-tuning a spectral response. This response is then used to perform material decomposition (MD). We propose a step-wedge phantom made of water and iodine to calibrate a prototype PCD-CT system. Four methods were tested and compared based on calibration accuracy and CT image quality. The exhaustive PCD response was not well calibrated, but a reduced model was defined that was able to perform accurate water/iodine MD and to reduce the ring artifact intensity. The impact of the number of energy bins (from two to seven) was also studied. The number of bins did not affect the spectral accuracy. However, compared to the two energy bin configuration, the seven bin configuration decreased the noise by 10% and 15% in the water and iodine maps, respectively. The model was tested on ex-vivo tissue samples injected with iodine to demonstrate the results of the water/iodine MD on biological materials.

The PandaX-4T experiment is designed for multiple purposes, including searches for solar neutrinos, weakly interacting massive particles, and rare double beta decays of xenon isotopes. The experiment produces a huge amount of raw data that needs to be stored for related physical analyses in a wide energy range. With the upgrading of the PandaX-4T experiment, the doubled sampling rate resulted in a larger data size, which challenges both the cost and the data processing speed. To address this issue, we propose a data reduction strategy by removing the noise tail of large signals and downsampling the remaining parts of them. This strategy reduces the requirement for storage by 65% while increasing data processing speed. The influences on physical analyses on different topics at different energy regions are negligible.

SiPM-coupled Cs₂LiYCl₆:Ce³⁺ (CLYC) detectors are widely used for detecting neutrons and gamma rays in mixed radiation environments. Intensities and energies are obtained from the output pulses of the detector, including normal and anomalous pulses. Since anomalous pulses can negatively affect measurement accuracy, this study designs a pulse selection algorithm to improve them. This algorithm calculates the ratio of the mean to the standard deviation of an output pulse in a particular time window and categorizes it as normal or anomalous. The algorithm also uses the difference in ratio value between neutrons and gamma rays for pulse shape discrimination. In an experiment using a SiPM-coupled CLYC detector, 200,000 sets of pulses were obtained for ¹³⁷Cs and Am-Be sources. The results indicate that this method can reject more than 94.2% of anomalous pulses, improving the energy resolution of ¹³⁷Cs source from 8.9% @ 662 keV to 8.4% @ 662 keV. The figure-of-merit (FOM) of pulse shape discrimination is 1.23 for the Am-Be source, and this method can select specific pulse types based on the pulse-ratio value. In addition, the method is suitable for all pulse-mode detectors.

The gravitational wave GW170817 from a binary neutron star merger and the simultaneous electromagnetic detection of the GRB170717A by Fermi Gamma-Ray Space Telescope, opened a new era in the multi-messenger astronomy. Furthermore, the GRBs (Gamma-Ray Bursts) and the mysterious FRBs (Fast Radio Bursts) have sparked interest in the development of new detectors and telescopes dedicated to the time-domain astronomy across the electromagnetic spectrum. Time-domain astronomy aims to acquire fast astronomical bursts in temporal range between a few seconds down to 1 ns. Fast InfraRed Bursts (FIRB's) have been relatively understudied, often due to the lack of appropriate tools for observation and analysis. In this scientific scenario, the present contribution proposes a new detection system for ground-based reflecting telescopes working in the mid-infrared (mid-IR) range to search for astronomical FIRB's. Experience developed in the diagnostics for lepton circular accelerators can be used to design temporal devices for astronomy. Longitudinal diagnostic instruments acquire bunch-by-bunch particle shifts in the direction of flight, that is equivalent to temporal. Transverse device integrates the beam signal in the horizontal and vertical coordinates, as standard telescopes. The proposed instrument aims to work in temporal mode. Feasibility study tests have been carried out at SINBAD, the infrared beam line of DAFNE, the e⁺e^- collider of INFN. SINBAD releases pulsed infrared synchrotron light with 2.7 ns separation. The front-end detector system has been evaluated to detect temporal fast infrared signals with 2–12 μm wavelengths and 1 ns rise times. The present contribute aims to be a step toward a feasibility study report.

The implementation of Slicon Photon-Multipliers (SiPMs) wave-length shifting (WLS) fibers light response system in liquid argon (LAr) is a promising technology for suppressing background in rare event experiments. Moreover, it is particularly relevant for experiments that utilize high-purity germanium (HPGe) detectors directly operated in LAr, such as the direct detection of dark matter and neutrinoless double beta decay. In this work, we exhibit a designed WLS fiber for the LAr detector, verify the feasibility of the manufacturing technology, and simulation research about its light collection performance. The novel fiber incorporates two materials, styrene and 1,1,4,4-tetraphenyl-1,3-butadiene (TPB). The pre-experiments proved that the fiber has good WLS and light-conducting properties for ultraviolet light. In addition, the effect of different light collection methods on detection efficiency was assessed by Geant4 simulation. Our results show that adding optical fibers can significantly increase light collection efficiency. Compared with the design of TPB coating with commercial fiber, the new structure of WLS fiber can improve the light collection efficiency by 50%. The simulation results indicate that the new fiber structure can enhance the light collection efficiency of the LAr detection system, thereby improving the anti-coincidence system's performance in rare event experiments.

Neutron detection systems are of increasing importance in applications from basic science to medical applications and reactors. ³He proportional counters remain the most popular choice for monitoring thermal neutrons with a detection efficiency of around 60%, however, due to ³He global shortages, a new generation of detection technologies will be required to meet the rising demand. As a result, extensive research is being conducted to investigate alternative methods of neutron detection. This work presents such a system and demonstrates its calibration and evaluation using an AmBe neutron source. The detection system involves silicon sensors coated by converter layers to make the detectors sensitive to thermal neutrons via neutron capture and measurement of the resulting secondary charged particles. The detection system is presented in two configurations, a single and a multi-layer configuration, where the latter is used to increase the total detection efficiency. In addition, the system is capable of determining coincident signals from a single neutron capture, a feature which allows background suppression and an increase in the purity of the neutron signal which is particularly useful in mixed radiation environments.

As a prototype detector for the SHiP Surrounding Background Tagger (SBT), we constructed a cell (120 cm × 80 cm × 25 cm) made from corten steel that is filled with liquid scintillator (LS) composed of linear alkylbenzene (LAB) and 2,5-diphenyloxazole (PPO). The detector is equipped with two Wavelength-shifting Optical Modules (WOMs) for light collection of the primary scintillation photons. Each WOM consists of an acrylic tube that is dip-coated with a wavelength-shifting layer on its surface. Via internal total reflection, the secondary photons emitted by the molecules of the wavelength shifter are guided to a ring-shaped array of 40 silicon photomultipliers (SiPMs) coupled to the WOM for light detection. The granularity of these SiPM arrays provides an innovative method to gain spatial information on the particle crossing point. Several improvements in the detector design significantly increased the light yield with respect to earlier proof-of-principle detectors. We report on the performance of this prototype detector during an exposure to high-energy positrons at the DESY II test beam facility by measuring the collected integrated yield and the signal time-of-arrival in each of the SiPM arrays. The resulting detection efficiency and reconstructed energy deposition of the incident positrons are presented, as well as the spatial and time resolution of the detector. These results are then compared to Monte Carlo simulations.

A small-area imaging detector prototype for position measurement of fission fragments produced in low energy heavy-ion reactions is presented in this study. The detector readout is equipped with a 2-dimensional, position-sensitive gaseous avalanche readout based on the novel Multi-Mesh Thick-GEM (MM-THGEM), and is coupled to a delay-line board for particle localization. The prototype has an effective area of 10 × 10 cm² and is operated in isobutane at low pressure (7–10 Torr). We present and discuss a series of systematic evaluation tests performed by irradiating the detector with α-particles and fission fragments emitted by small-rate sources (²⁴¹Am, ²⁴⁹Cf and ²⁵²Cf). Position and time resolutions of about 0.42 mm and 1 ns were achieved, respectively. This work serves as a benchmark for the development of a large-scale array of detectors for experiments with fission and fission-like reaction products at the Facility for Rare Isotope Beams (FRIB).

An experimental study has been performed using 14 MeV neutrons for imaging of low Z material (particularly composed of C, H, O elements) masked with thick layers of dense and high Z materials. The experimental setup consists of a D-T neutron generator, a metallic collimator and an imaging system. The imaging system is designed with a polypropylene zinc sulphide scintillator screen integrated with a lens coupled 16-bit ICCD camera. Imaging capability of the system was investigated using iron test samples with holes and line pair features. The minimum hole size of 2 mm could be imaged at a contrast of 36% and a line of 2 mm width visible at a contrast of 24% indicating the system's resolution of ∼ mm. Low Z samples such as water (H₂O) and polyethylene (C₂H₂)_n placed behind thick layers of Pb (40 mm) and Uranium (35 mm), were imaged successfully. These images reveal the system's ability towards low Z material imaging in the presence of heavier metals. Good contrast images acquired at a lower neutron yield of ∼ 5 × 10⁸ n/sec of D-T neutron generator has provided a possibility to realise fast neutron imaging having moderate resolution (∼ mm) with a smaller footprint and an economical system design for field applications.

With the expanding reach of physics, xenon-based detectors such as PandaX-4T in the China Jinping Underground Laboratory aim to cover an energy range from sub-keV to multi-MeV. A linear response of the photomultiplier tubes (PMTs) is required for both scintillation and electroluminescence signals. Through a dedicated bench test, we investigated the cause of the non-linear response in the Hamamatsu R11410-23 PMTs used in PandaX-4T. The saturation and suppression of the PMT waveform observed during the commissioning of PandaX-4T were caused by the high-voltage divider base. The bench test data validated the de-saturation algorithm used in the PandaX-4T data analysis. We also confirmed the improvement in linearity of a new PMT base design with three more low radioactivity capacitors at later dynodes, which will be used to upgrade the PMT readout system in PandaX-4T.

The fiber-optic neutron detector consists principally of a neutron-sensitive scintillator, optical fiber, and photomultiplier tube. It has features such as small size, real-time online measurement capability, and high resistance to electromagnetic interference. This detector is excellent for neutron detection in areas with limited space and strong electromagnetic interference. However, its small size results in a comparatively low neutron sensitivity. The goal of this study is to look into the relationship between detector parameters and performance in order to improve the detector design. The research begins with the development of a detector model using Monte Carlo simulation programs to investigate the relationship between the⁶LiF/ZnO:Ga mass ratio, thickness, wavelength-shifting fiber length, and detector performance. The ⁶LiF/ZnO:Ga mass ratio was then used as the test parameter to create equivalent detector samples for experimental validation. The results show that the detector has the highest neutron sensitivity when the mass ratio of⁶LiF/ZnO:Ga is 1:1. This pattern is consistent with theoretical simulation results, indicating that the optimization strategy for detector parameters is feasible. The results of this work give a theoretical foundation for the development and practical implementation of the fiber-optic neutron detector.

In this paper, a compact square stub-loaded band pass filter (BPF) is designed and investigated for quality factor improvement analysis. A detailed analysis has been presented to demonstrate the superior power handling capability of the proposed microstrip bandpass filter without any degradation in its electrical performance parameters. For this purpose, square-type stubs are incorporated in the proposed bandpass filter which reduced the maximum peak voltage and increased the high peak threshold, instead of using sharp edges. Also, an in-depth analysis of peak voltage with a center frequency of 2.1 and 4.2 have been carried out by considering some parameters like pressure and quality. The proposed bandpass filter shows minimum peak voltage of 1.61 V and 1.59 V across the frequency of 2.1 GHz and 4.2 GHz which covers the application of mobile and radio altimeters. The designed BPF shows the minimum heat generation of 0.29 and 0.89 per watt at the resonating frequencies of 2.1 and 4.2 GHz. Furthermore, the proposed bandpass filter presents an in-depth analysis of several characteristic parameters such as return loss, insertion loss, power loss, delay in group and phase, current distribution, H and E field distribution and maximum power loaded and unloaded quality factor.

The PANCAKE facility is the world's largest liquid xenon test platform. Inside its cryostat with an internal diameter of 2.75 m, components for the next generation of liquid xenon experiments, such as DARWIN or XLZD, will be tested at their full scale. This is essential to ensure their successful operation. This work describes the facility, including its cryostat, cooling systems, xenon handling infrastructure, and its monitoring and instrumentation. The inner vessel has a flat floor, which allows the full diameter to be used with a modest amount of xenon. This is a novel approach for such a large cryostat and is of interest for future large-scale experiments, where a standard torispherical head would require tonnes of additional xenon. Our current xenon inventory of 400 kg allows a liquid depth of about 2 cm in the inner cryostat vessel. We also describe the commissioning of the facility, which is now ready for component testing.

Evaluation of detectors for a soft X-ray imaging spectrometer has resulted in the need to understand the effect of charge spreading on apparent detector noise properties, and therefore achievable energy resolution. This paper presents a mathematical model for the processes leading to increased uncertainty within a simplified X-ray reconstruction process. This is a description for additional uncertainty introduced by the process of collecting X-ray generated electrons into a region of noisy pixels and reconstructing the recorded pixels values back into an estimated X-ray energy value. The predictions of the model, and preliminary experimental verification are shown.

The CO₂ laser interferometer is an important diagnostic system in the HUST Field Reversed Configuration (HFRC) and can provide routine electron density measurement for plasma experiments. A commercial laser (λ = 10.6 μm) with a maximum output power of 20 watts is used as the laser source for the interferometer, which can pose a threat to the safety of experimenters and experimenters' experimental environment. Moreover, most of the components of the system are sensitive to the temperature and humidity of the environment. For the aim of safe and stable operation, it is necessary to develop a CO₂ interferometer control system (CICS). A module was innovatively designed with a servo to regulate power according to commands and protect timely when a fault takes place. Additionally, a special device using a stepper motor can automatically regulate and release the laser according to the different stages of the experiment. The hardware design of the CO₂ control system incorporates the ESP32 microcontroller, servo and stepper motor, which can automatically monitor, regulate and protect in case a fault takes place. The software implementation of the interaction is based on the OneNET platform and is first used on the CO₂ interferometer, linking in the Internet based on Internet of Things (IoT) technologies to each sensor and device in the control system, which can achieve visualization monitoring and remote control. With the operation of CICS, the CO₂ interferometer can run stably and be timely protected.

The fault diagnosis of rolling bearings based on deep networks is hindered by the unexpected noise involved with accessible vibration signals and global information abatement in deepened networks. To combat the degradation, a multi-scale deep residual shrinkage network with a hybrid attention mechanism (MH-DRSN) is proposed in this paper. First, a spatial domain attention mechanism is introduced into the residual shrinkage module to represent the distance dependence of the feature maps. Then, a hybrid attention mechanism considering both the inner-channeled and cross-channeled characteristics is constructed. Through the comprehensive evaluation of the feature map, it provides a soft threshold for the activation function and realizes the feature-map selection adaptively. Second, the dilated convolution with different dilation rates is implemented for multi-scale context information extraction. Through the feature combination of the DRSN and the dilated convolution, the global information of the rolling bearing fault is strengthened and preserved as the fault diagnosis network is deepened. Finally, the performance of the proposed fault-diagnosis model is validated on the dataset from Case Western Reserve University (CWRU). The experimental results show that, compared with common convolution neural networks, the proposed neural diagnosis model provides a higher identification accuracy and better robustness under noise interference.

A novel approach has been proposed to effectively separate cascaded and closely packed full energy peaks in the energy spectrum of γ detector arrays. By conducting a sequence of γ-γ coincidence analyses on the energy spectrum, it is feasible to obtain a spectrum that represents the product of these packed peaks. We have designated the newly obtained spectrum as the "product spectrum". The energy spectrum and the newly obtained product spectrum can be simultaneously fitted, enabling a more precise fitting and separation of the closely packed peaks. This method has been mathematically proven, and validated through the use of Monte Carlo simulation. The systematic errors of this method are also taken into consideration.

The Low Energy X-ray Telescope (LE) is an important instrument of the Insight-Hard X-ray Modulation Telescope (Insight-HXMT), which performs scanning and point observation in the soft X-ray energy band (0.7–13 keV). Since its launch in 2017, it has conducted a large number of scientific observations and achieved significant astronomical discoveries. LE is composed of three detector boxes and an electronic control box. The data acquisition system of LE is designed to use periodic sampling, which solves the problem of unstable noise peaks. Data loss may occur when observing X-ray bursts, and periodic sampling provides a method of correcting light curves. In addition, in the South Atlantic Anomaly (SAA) or where the count rate of the particle monitor on the Insight-HXMT is very high, LE automatically switches into SAA operating mode, and only a small number of events are recorded. After data correction, the light curves can be estimated to expand the astronomical achievements of LE.

Low gain avalanche detectors (LGADs) deliver excellent timing resolution, which can mitigate mis-assignment of vertices associated with pileup at the High Luminosity LHC and other future hadron colliders. The most highly irradiated LGADs will be subject to 2.5 × 10¹⁵n_eq cm^-2of hadronic fluence during HL-LHC operation; their performance must tolerate this. Hamamatsu Photonics K.K. and Fondazione Bruno Kessler LGADs have been irradiated with 400 and 500 MeV protons respectively in several steps up to 1.5 × 10¹⁵n_eq cm^-2. Measurements of the acceptor removal constants of the gain layers, evolution of the timing resolution and charge collection with damage, and inter-channel isolation characteristics, for a variety of design options, are presented here.

We introduce a new pattern recognition algorithm for track finding in High Energy Physics Experiments based on an extension of the Hough Transform to multiple dimensions. A remarkable property of this algorithm is that the execution time is simply proportional to the total number of the hits to be processed, making it particularly attractive for high occupancy situations. The algorithm needs to be trained using a sufficiently large set of simulated tracks. The same track finding algorithm can be used for very different detector geometries and only the set of simulated tracks used for training needs to be changed. The particular structure of the algorithm also lends itself naturally to parallel hardware implementations which, combined with its intrinsic flexibility, should provide a most powerful tool for triggering at future colliders.

The Multi-Blade (MB) Boron-10-based neutron detector is the chosen technology for three instruments at the European Spallation Source (ESS): the two ESS reflectometers, ESTIA and FREIA, and the Test Beam Line. A fourth MB detector has been built, installed and commissioned for the user operation of the reflectometer Amor at PSI (Switzerland). Amor can be considered a downscaled version of the ESS reflectometer ESTIA. They are based on the same Selene guide concept, optimized for performing focusing reflectometry on small samples. The experience gained at Amor is invaluable for the future deployment of the MB detector at the ESS. This manuscript describes the MB detector construction and installation at Amor along with the readout electronics chain based on the VMM3a ASIC. The readout chain deployed at Amor is equivalent of that of the ESS, including the readout master module (RMM), event-formation-units (EFUs), Kafka, FileWriter and live visualisation tools.

The impact parameter characterizes the centrality in nucleus-nucleus collision geometry. The determination of impact parameters in real experiments is usually based on the reconstructed particle attributes or the derived event-level observables. For the scheduled Cooler-storage-ring External-target Experiment (CEE), the low beam energy reduces correlation between the impact parameter and charged particle multiplicity, which decreases the validity of the explicit determination methods. This work investigates a few neural network-based models that directly take the digitized signals from the external Time-of-flight detectors as input. The model with the best performance shows a mean absolute error of 0.479 fm with simulated U-U collisions at 0.5 AGeV. The performances of the models implemented with digi inputs are compared with reference models with phase space inputs, showing the capability of neural networks to handle the original but potentially interrelated digitized signal information.

The harsh environmental conditions in the marine environment pose various constraints on developing efficient instruments to carry out long-term, in situ radioactivity measurements. In addition, the strong attenuation of γ-rays in the water medium, makes remote sensing of such radiation a challenging task. In the present work, we report on the efforts to find the optimal characteristics and deployment scenarios of a new prototype γ-ray instrument based on a small-size CZT crystal enclosed in seal-tight housing to be deployed for operation in large depths. Lab experiments and detailed Monte Carlo simulations were combined to validate the actual crystal dimensions, determine its efficiency and energy resolution, as well as establish the minimum detectable activity values of the instrument in different configurations and scenarios.

A compact radio frequency quadrupole (RFQ) linac for accelerator-based boron neutron capture therapy is being developed at Xi'an Jiaotong University. By adopting a ramped inter-vane voltage in the beam dynamics design, the RFQ could accelerate a continuous wave proton beam to 2.6 MeV over a length of 4 m, effectively decreasing costs and saving space. To meet the beam-dynamics requirements, both the vane width and undercut were optimized during the electromagnetic design. In addition, π-mode stabilization loops were included to increase the mode separation, and fixed tuners with varying diameters were installed to obtain close frequency-tuning sensitivity. It was established that the field unflatness can be controlled within ±1.5% when all tuners remain at their nominal insertion depth. Optimized cooling-channel design was completed, and multi-physics analysis was conducted. The water tuning coefficients of the vane and wall channels were analyzed to establish the ability to fine tune the RFQ during operation.

In this work a detector prototype built as an array of Scintillating Plastic Optical fibers (SPOFs) is presented. The primary aim of this detector is to improve spatial resolution, provide real-time dose mapping and a tissue equivalent detector in radiobiology experiments. Details on the design and construction are provided along with the initial tests carried out using low-energy X-ray and electrons from a ⁹⁰Sr source. Regarding the design and construction of the detector, the mechanical design of the irradiation box is presented and the Quality Assurance (QA) the optical fiber arrays were subjected to is discussed. The QA measurements show that the alignment of the optical fibers is within acceptable tolerances for dose readout. After the detector assembly, correction factors for each fiber were extracted from tests using a collimated X-ray beam. Special care was taken to ensure that each fiber is submitted to the same dose. Broad field tests show that the measurements are reproducible to within 3 %. Potential innovative features of this system for radiobiological experiments are discussed as well as the future follow-up of the prototype.

The NA62 experiment at CERN utilises a differential Cherenkov counter with achromatic ring focus (CEDAR) for tagging kaons within an unseparated monochromatic beam of charged hadrons. The CEDAR-H detector was developed to minimise the amount of material in the path of the beam by using hydrogen gas as the radiator medium. The detector was shown to satisfy the kaon tagging requirements in a test-beam before installation and commissioning at the experiment. The CEDAR-H performance was measured using NA62 data collected in 2023.

Laser-driven shock waves in matter propagate with multiple kilometers per second and therefore require sources like a laser-driven backlighter, which emit the X-rays within picoseconds, to be able to capture sharp images. The small spatial extent of shocks in low-density materials pose challenges on the imaging setup. In this work, we present a design process for a single-shot X-ray phase-contrast imaging system geared towards these objects, consisting of a two-grating Talbot interferometer and a digital X-ray detector. This imaging system is optimized with respect to the detectable refraction angle of the X-rays induced by an object, which implies a high phase sensitivity. Therefore, an optimization parameter is defined that considers experimental constraints such as the limited number of photons, the required magnification, the size and spectrum of the X-ray source, and the visibility of the moiré fringes. In this way, a large parameter space is sampled and a suitable imaging system is chosen. During a campaign at the PHELIX high-power laser facility a static test sample was imaged which is used to benchmark the optimization process and the imaging system under real conditions. The results show good agreement with the predicted performance, which demonstrates the reliability of the presented design process. Likewise, the process can be adapted to other types of laser experiments or X-ray sources and is not limited to the application presented here.

Score based generative models are a new class of generative models that have been shown to accurately generate high dimensional calorimeter datasets. Recent advances in generative models have used images with 3D voxels to represent and model complex calorimeter showers. Point clouds, however, are likely a more natural representation of calorimeter showers, particularly in calorimeters with high granularity. Point clouds preserve all of the information of the original simulation, more naturally deal with sparse datasets, and can be implemented with more compact models and data files. In this work, two state-of-the-art score based models are trained on the same set of calorimeter simulation and directly compared.

A compact accelerator-driven neutron source is proposed at Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, called Sun Yat-Sen University Proton Accelerator Facility (SYSU-PAFA). The proton accelerator is composed of a proton electron cyclotron resonance source, a four-vane radio frequency quadrupole (RFQ), and an alternative phase focusing drift tube linac (APF-DTL). It can accelerate 10 mA proton beam to 8 MeV. Due to the high current, beam matching is particularly important. In order to achieve beam matching between various components, beam transport sections are needed. The beam transport line is divided into three segments. The Low Energy Beam Transport (LEBT) ensures that the beam parameters are matched before entering the RFQ. The Medium Energy Beam Transport (MEBT) segment efficiently transfers the beam between the RFQ and DTL. The High Energy Beam Transport (HEBT) focuses on transporting the beam to the targets. The design goal of beam transport line is as short as possible while ensuring high efficiency of beam transportation. SYSU-PAFA has an overall transmission efficiency of 99%, with optimal transverse matching conditions between beam transport and RFQ or DTL accelerators. The efficient use of solenoids and magnets allows for a compact transmission section, resulting in a total length of 13.6 meters, shorter than most accelerators at the same beam energy. This paper will provide the detailed beam dynamics of the compact accelerator.

A new scheme of low energy negative muon source with muon catalyzed fusion (MuCF) is described. In the MuCF reaction process, muonic helium ions (μHe⁺) are created. By re-accelerating and stripping μHe⁺ ions, a low emittance negative muon beam is generated.

Photoelectron signal amplification in gas photomultipliers (GPMs) is achieved through charge avalanche development in the holes of a cascade of hole-type microperforated foils. When a voltage difference is applied between the metal film electrodes that are deposited on both surfaces of those foils, an electric field with a high intensity is established inside the holes. As a consequence, each electron entering those holes produces an electron avalanche that emerges from the other side of the holes. A cascade of few foils is necessary for a single primary electron to produce a final avalanche intense enough to be read out, in the anode electrode, above the electronic noise. We propose the Photon Induced Scintillation Amplifier (PISA), where the photoelectron signal amplification is obtained by reading out the photon scintillation produced in the charge avalanches of solely one Micro-Hole-and-Strip-Plate-type microstructure with SiPMs. The optical readout has the advantage of having the extra gain from the photosensor and is less sensitive to electronic noise. A large photosensor gain produces large output signals that can travel over long distances without significant degradation. This allows for the readout electronics to be placed away from the photosensor and, thus, from the detector sensitive volume. The scintillation readout plane can be made of a 2D-array of SiPMs, with size and pitch in accordance with the needed scintillation level and position resolution. A first basic prototype was assembled to present a proof-of-principle of the PISA concept.

A typical method to produce negative ion beams uses alkali vapour as a medium for a double charge exchange to convert incident positive (1+) beams to negative (1-) beams. Alkali vapours pose a problem in ion production as they are flammable, explosive and cause vacuum surface contamination. Thus, it is advantageous to use non-metallic vapours for charge exchange as it will prevent hazards and the contamination of vacuum surfaces and targets in which the negative ion beams are incident upon. In this paper we will describe and demonstrate the process of creating negative ion beams by impinging a 15 keV to 30 keV beam from D-Pace's TRIUMF licenced H^- volume-cusp ion source (1 mA to 15 mA) onto a volume of non-metallic neutral gas (X) resulting in a single or two-step charge exchange: H^- + X → H + X^- or H^- + X → H + X + e → H + X^-. The newly created X^- ion beams will be accelerated by a (1 to 20) kV electrostatic accelerator and passed through a mass spectrometer system to separate the primary H^- beam from the X^- beam. The two gases studied are He and H₂ and we will present the magnitude of the resultant beam currents after being separated from the incident H^- beam by the mass spectrometer system.

At the Electron Ion Collider, quasi-real photoproduction measurements involve tracking scattered electrons at small angles relative to the beamline. These electrons act as effective beams of tagged almost-real photons, with a high flux compared to larger Q² interactions. However, the proximity of the detector to the electron beam results in a very high flux of electrons from the bremsstrahlung process (about 10 electrons per 12 ns electron/ion bunch crossing over an area of approximately 100 cm²). Consequently, the tracking detector systems experience high occupancy. To address this, we propose using machine learning algorithms, specifically object condensation methods, which excel at track building in the quasi-real photon tagger. These algorithms achieve track finding efficiency of 95% or higher and purity of 90% or higher, even in the presence of noise and hit detection inefficiencies.

Secondary X-ray radiation for the sterilizer based on high-current repetitively pulsed electrons accelerator SINUS-320 has been investigated. The energy of accelerated electrons is 500 keV. In this regard, there is a need for radiation protection during operation of the installation, which, in turn, leads to the importance of studying the dose rate of secondary X-ray radiation. The studies were carried out by statistical modeling using the GEANT4 simulation toolkit.

This paper presents the results of charged particle track reconstruction in CLAS12 using artificial intelligence. In our approach, we use machine learning algorithms to reconstruct tracks, including their momentum and direction, with high accuracy from raw hits of the CLAS12 drift chambers. The reconstruction is performed in real-time, with the rate of data acquisition, and allows for the identification of event topologies in real-time. This approach revolutionizes the Nuclear Physics experiments' data processing, allowing us to identify and categorize the experimental data on the fly, and will lead to a significant reduction in experiment data processing. It can also be used in streaming readout applications leading to more efficient data acquisition and post-processing.

The successful realization of the EIC scientific program requires the design and construction of high-performance particle detectors. Recent developments in the field of scientific computing and increased availability of high performance computing resources have made it possible to perform optimization of multi-parameter designs, even when the latter require longer computational times (for example simulations of particle interactions with matter). Procedures involving machine-assisted techniques used to inform the design decision have seen a considerable growth in popularity among the EIC detector community. Having already been realized for tracking and RICH PID detectors, it has a potential application in calorimetry designs. A SciGlass barrel calorimeter originally designed for EIC Detector-1 has a semi-projective geometry that allows for non-trivial performance gains, but also poses special challenges in the way of effective exploration of the design space while satisfying the available space and the cell dimension constraints together with the full detector acceptance requirement. This talk will cover specific approaches taken to perform this detector design optimization.

The adherence of the p-Terphenyl film to the substrate in the X-ARAPUCA dichroic filter is directly correlated with the long-term efficiency and durability of this device. This study presents the results of different cleaning methods established to analyze their contributions to the film's adherence to the substrate. The samples underwent analysis of their crystalline and morphological structure using XRD and AFM techniques. Three distinct techniques were employed in the adherence tests: ultrasonic bath, scratch test, and cryogenic immersion method with turbulence, as these devices will be submerged in liquid argon in the DUNE experiment. Results suggest that the deposited PTP layer exhibits a monoclinic crystalline structure, with topography revealing percolated planar grains and roughness ranging from 13 nm to 18 nm. The various adherence techniques employed yielded consistent results, highlighting the standard cleaning process involving Soap + H₂O + N₂ + Kiln as the preferred method.

This article explores the integration of Deep Learning and Explainable Artificial Intelligence in Particle Physics, focusing on their application in position reconstruction within dual-phase liquid argon detectors for Dark Matter search. Facing challenges like pile-up scenarios, Neural Networks prove crucial for refining algorithms. This article emphasizes Deep Learning's role in addressing regression and classification problems, such as position reconstruction and particle identification, particularly in Time Projection Chambers. Explainable Artificial Intelligence emerges as pivotal in unraveling Deep Learning's complex decisions, exposing biases, and facilitating improvement cycles. Innovations like Evolutionary Neural Networks and topology-driven dataset reduction offer potential efficiency gains. The conclusion highlights challenges in analyzing massive data volumes, emphasizing the need for adaptability and ethical considerations in the pursuit of understanding Dark Matter.

The Jiangmen Underground Neutrino Observatory (JUNO) aims to determine the neutrino mass hierarchy by detecting antineutrinos from nuclear reactors using a large liquid scintillator volume. The detector employs approximately 20,000 20-inch photomultiplier tubes powered and read out by two electronics readout systems: underwater and above water. The back-end card (BEC) is a crucial component of the latter and links 7,000 underwater electronics boxes to the trigger system. 180 BECs have been installed and tested at the JUNO site, including self-tests and combined tests. This paper presents the current status of the BEC.

The set of frequencies and angular properties of radiation emitted from a solid-state crystalline undulator based on the channeling effect are considered. High-frequency and low-frequency branches of the undulator radiation and the angular distribution of the emitted radiation are analyzed. The ranges of frequencies and angles of radiation emitted from the solid-state crystalline undulator based on the channeling effect are found. The frequency splitting and the energy threshold in the production of undulator radiation are shown and discussed.

In this work the dependence of the anomalous absorption of X-rays on the crystal thickness and temperature gradient value was studied. The refracted and reflected beams intensities, as well as their sum intensities were measured for crystal thicknesses in the range of 0.3–4.5 mm. Significant increase in the sum intensity of the refracted and reflected beams is observed in presence of temperature gradient. It is shown that the anomalous absorption in the crystal in presence of the temperature gradient is decreased and this effect is stronger expressed in thick crystals.

The influence of the angular profile of crystal reflectivity on the assessment of the divergence of a beam of relativistic electrons is studied through measurements of the angular distribution of diffracted transition radiation. The results show that, when the angular distribution of reflectivity is taken into account, the obtained divergence values are close to the true values. Failure to take this effect into account leads to systematic errors in determining the horizontal divergence. The magnitude of the error depends on the beam divergence and is inversely proportional to the square of the energy of the reflected photons.

Silicon is commonly used as a sensor material in a wide variety of imaging application. In recent high-energy and intensity beam experiments, high radiation tolerance is required, and new semiconductor detector consisting of radiation-hard materials have been investigated. The Cu(In,Ga)Se2 (CIGS) semiconductor is expected to possess high radiation tolerance, with the ability to recover from radiation damage through the compensation of defects by ions. The CIGS has originally developed for a solar cell and its radiation tolerance was investigated for the usage in space. The CIGS, featuring a recovery capability, would shed new light to particle detecror in high radiation environments. CIGS detectors (2 and 5 μm thick) were tested by Xe ion (400 MeV/u, ¹³²Xe⁵⁴⁺) at HIMAC, successfully detecting single Xe ion with a fast response. The output charge is understandable through estimation with the GEANT4 simulation. With 0.6 MGy irradiation by Xe ions, the CIGS output degraded to 50%, but it was recovered to 97% after the heat treatment under 130°C for 2 hours. This marks a significant step in confirming that CIGS semiconductors can serve as particle detectors with recovery features for radiation damage.

One of the important parameters characterizing the interaction of electron beams with matter is the depth dose distribution. To develop a new approach for shaping electron beams using specially created materials suitable for the manufacture of complex 3D-printed devices, it is necessary to analyze the features of ionizing radiation propagation. In this work, numerical simulations and experimental studies of the interaction between electron beams and plastic materials weighted with metallic impurities of different concentrations, suitable for fabricating samples using the rapid prototyping method, were carried out. Sets of plates made from the investigated plastics were created using the fused filament fabrication (FFF) technique. Since the FFF sample fabrication process involves forming objects from a thermoplastic mass through layer-by-layer alignment, a distinctive feature of the printed samples is their lower actual density compared to the density of the material (filament) from which they are made. Taking this fact into account, the actual density of the polymer plates was calculated. Based on this data, numerical models of the plastic materials weighted with metallic impurities were developed, and virtual models of the experimental setup were created to calculate the electron beam depth dose distributions in the materials. In the next step of the investigation, experimental studies were performed using electron beams with energies of 6 and 10 MeV. Pre-calibrated GafChromic EBT3 dosimetry films were used as detectors to obtain the experimental data on the electron beam depth dose distributions in the materials under consideration. It was observed that with an increasing concentration of metal impurities in the plastic base, the depth dose distribution moves into smaller thicknesses. It was observed that the simulation and experimental results are in good agreement.

Analytical study and summarization of dynamic and frequency characteristics of the seismic-acoustic vibrations originated by the near and distant earthquakes and other natural and artificial seismic processes, as well as information analyses of their duration and repetition were done. These allow the formulation of appropriate technical requirements for seismic recording devices, as well as to analyze and evaluate the possibilities of implementing various methods and devices for recording signals from different seismic-acoustic processes depending also on the seismological and other tasks to be solved and various additional specific requirements. It has been shown, that although the introduction of various methods and devices for the digital recording of seismic signals substantially increased during the last decades in seismology, however, it is not even possible to record seismic signals in their entire possible amplitude-frequency ranges employing a single digital recording device too. It also has been confirmed that the widespread usage of digital recording, transmission, machine processing, and analyzing of seismic signals in most contemporary seismic stations does not reduce the value and does not eliminate the need, but, on the contrary, assumes the conduction of simultaneous analog visible registration of seismic processes to obtain express controlling visible records, provide operational manual express analysis of seismograms.

This paper presents the results of an investigation of the electrical, dielectric, ferroelectric, and second-order nonlinear optical properties of SrB₄O₇ synthesized by methods of both solid-state reaction (SSR) and crystallization of a glass tape (GT). To obtain GTs of SrB₄O₇, the melt consisting of appropriate precursors was rapidly cooled using a twin-roller. The prepared GTs were crystallized at 730°C for different durations and analyzed by X-ray diffraction. The formation of "extended" crystals in the central part of GTs due to the application of the GT technology is discussed. The investigation of the current-voltage characteristic of the sample prepared by SSR showed that its breakdown voltage is higher than 1000 V. The measurements of the dielectric parameters in the frequency range of 1 KHz–1 MHz showed that the dielectric constant is about 7.5, and the dielectric loss varies from 0.002 to 0.0008. These parameters are sufficiently stable in the temperature range from room temperature to 150°C. The ferroelectric properties of the GT crystallized at 730°C for 3 h were also investigated. At 20 kV/cm, a remnant polarization of 0.18 μC/cm² was measured. Optical measurements showed that the intensity of second-harmonic generation in the GT crystallized at 730°C for 3 h is 5.4 times higher than that of KH₂PO₄ (KDP).

The ICARUS-T600 detector is a 760-ton Liquid Argon Time Projection Chamber (LArTPC) currently operating at Fermilab as the Far Detector in the Short Baseline Neutrino (SBN) program. The SBN program is composed of three LArTPCs with a central goal of testing the sterile neutrino hypothesis. After operating for 3-years in the Gran Sasso Underground Laboratory, the ICARUS detector was shipped to CERN where it was outfitted with 360 8" Photomultiplier Tubes (PMTs) for a new optical detection system. The PMT system detects fast scintillation light from charged particles interacting in the Liquid Argon, generating the trigger signal for the full detector and allows 3D reconstruction of events. Now operating at shallow depth, the detector is exposed to a high flux of cosmic rays that can fake neutrino interactions. To mitigate this effect a Cosmic Ray Tagger (CRT) and a 3-meter-thick concrete were installed. Precise timing information from both the PMT and CRT subsystems can help to identify whether an interaction originated from inside or outside of the ICARUS cryostat. This paper reviews a method for cosmogenic background reduction and timing calibration of the CRT and PMT light detection systems in ICARUS.

In the context of the European strategy for particle physics, the Multi-TeV Muon Collider has emerged as a compelling alternative for advancing our understanding of the Standard Model, after the full exploitation of the High-Luminosity LHC. The physics programme at the Muon Collider includes precise measurements in the Higgs boson sector and the search for new physics at the TeV scale. Achieving these goals relies on accurate full event reconstruction, including the identification and precise four-momentum estimation of various particles. The Particle Flow (PF) algorithm is one of the most suitable approach for this task, exploiting information from tracking, calorimeter, and muon detectors for particle identification and measurements of their momenta/energies. Tracking detectors measure charged particle momenta, while calorimeters provide energy measurements for photons and neutral hadrons. Therefore, a combination of an exceptional tracking system and high-granularity calorimeters is necessary. However, one of the biggest challenges for a future experiment at the Muon Collider is to discriminate the product of the  μμ collisions from the intense beam-induced-background (BIB), due to the unstable nature of muons, whose decay products interact with the detector material. To address this, an innovative hadronic calorimeter (HCAL) based on Micro Pattern Gas Detectors (MPGDs) is proposed. MPGDs offer robust technology for high radiation environments and a high granularity for precise spatial measurements. Dedicated studies are needed to assess and optimize the performance of an MPGD-based HCAL, including the development of medium-scale prototypes for performance measurements. The response of HCAL to incoming particles is examined through Monte Carlo simulations using Geant4, comparing the performance of digital and semi-digital readouts, with energy resolution as the figure of merit. The simulated geometry will be integrated into the Muon Collider software to study its impact on jet reconstruction within the full apparatus and in the presence of BIB. The simulation will be also validated through the test of a small-size calorimeter cell equipped with advanced resistive MPGD technologies, namely resistive MicroMegas, resistive μRWELL and RP-WELL.

Boron Neutron Capture Therapy (BNCT) is a therapeutic treatment for malignant tumors that utilizes the nuclear reactions that happen when thermal neutrons are captured by boron-10 atoms to selectively destroy designated cells. Boron-10 atoms are biochemically accumulated inside the tumor target, which is then irradiated with thermal neutrons. In recent years, the possibility to obtain accelerator based intense neutron beams has given a boost to the diffusion of BNCT also in Europe, removing the need of nuclear reactors. In this contest, the monitoring and characterization of the epithermal neutron beams dedicated to BNCT becomes an important issue. The directional neutron spectrometer called NCT-WES (Neutron Capture Therapy Wide Energy Spectrometer) is a single moderator neutron spectrometer composed of a polyethylene cylinder embedding six semiconductor-based detectors positioned at different depths along the cylinder axes. The position of the six detectors is studied in order to maximize the response of each one in a selected neutron energy range. The unfolding of the six simultaneous readings allows to reconstruct the incoming neutron energy spectrum as in a parallelized Bonner Sphere System. A cylindrical collimator situated in the front of the spectrometer makes the instrument sensitive to neutrons coming only from a given direction, which allows to exclude the contribution of the room scattered radiation. The experimental validation of the spectrometer, obtained through several measuring campaigns, is reported and discussed.

The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN aims to achieve unprecedented levels of instantaneous and integrated luminosities, approximately 5 × 10³⁴ cm^-2 s^-1 and 3000 fb^-1, respectively. It is anticipated that each bunch-crossing will result in an average of 140 to 200 collisions (pileup). The lead tungstate crystals and avalanche photodiodes (APDs) in the barrel region of the electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) will remain effective. However the readout and trigger electronics will undergo complete replacement to keep the current level of performance. A dual gain trans-impedance amplifier and an application-specific integrated circuit will be installed, providing two 160 MS/s analog-to-digital converter channels, gain selection, and data compression. The increase in noise within the APDs, due to radiation-induced dark current, will be alleviated by reducing the operating temperature of the ECAL. Additionally, the trigger primitive formation will be shifted away from the detector and handled by powerful and flexible field-programmable gate array processors housed on the back-end electronics cards. In this document, the complete ECAL barrel readout chain design and the current state of research and development for each individual component regarding the upgrade will be described. The outcomes of recent test beam campaigns conducted at the CERN SPS, exploiting electron beams with energies of up to 250 GeV, will also be summarized. Notably, measurements pertaining to the energy resolution performance of the latest prototypes of HL-LHC ECAL readout electronics will be presented.

Maintaining the required performance of the CMS electromagnetic calorimeter (ECAL) barrel at the High-Luminosity Large Hadron Collider (HL-LHC) requires the replacement of the entire on-detector electronics. 12240 new very front end (VFE) cards will amplify and digitize the signals of 61200 lead-tungstate crystals instrumented with avalanche photodiodes. The VFE cards host five channels of CATIA pre-amplifier ASICs followed by LiTE-DTU ASICs, which digitize signals with 160 MS/s and 12bit resolution. We present the strategy and infrastructure developed for achieving the required reliability of less than 0.5% failing channels over the expected lifetime of 20 years. This includes the choice of standards, design for reliability and manufacturing, as well as factory acceptance tests, reception testing, environmental stress screening and calibration of the VFE cards.

The paper describes a new figure of merit reachable in terms of very low power dissipation for a 12 bit, 40 MS/s Analog to Digital Converter in a 65 nm CMOS process with 1 V power supply. A differential time interleaved successive approximations register architecture is used. Each individual ADC channel is optimized with regard to power consumption hence interleaving 28 ADC channels in an analog memory like method, the total power consumption is only 280 μW including all the reference voltage drivers, the clock management and the digital sections. The total layout area of this converter is 0.87 mm².

This paper presents the design and measurement results of a 768-channel of a 14-bit analog to digital converters. Each sampling channel is equivalent to a pitch of only 8.5 μm with a possible sampling rate from 40 KS/s up to 100 KS/s. Test results show crosstalk of just ⁺/_-1 LSB. The circuit architecture and layout structure make it scalable to an exceptionally large format of detectors beyond 1000 channels. The circuit is designed to be used as a side element for multi-channel readout systems or as an IP for transfer to very dense integrated circuits.

The work investigates the conditions for the possibility of using the quadratic approximation U(ρ) = αρ² for the interaction potentials of channeled positrons with the inner walls of non-chiral carbon nanotubes of types (n, 0) and (n, n). In particular, (8, 0), (10, 0), (12, 0) and (8, 8), (10, 10), (12, 12) nanotubes were selected. In this case, when calculating the single-particle potential of the carbon atom, only the contribution of valence electrons was taken into account. As a result of this approximation, the parameters α were determined for all the nanotubes studied. Using wave functions and the corresponding quantum levels of transverse energy obtained by solving the Schrödinger equation, the probabilities of occupation of these levels were calculated for positron beams with zero angular dispersion moving along the axes of nanotubes. Based on this information, values of the longitudinal energy of positrons for which the quadratic approximation is applicable were determined for all the studied nanotubes. Spectral distributions of spontaneous radiation were calculated in the dipole approximation for non-dispersive relativistic positron beams, both within the framework of quantum-mechanical and classical approaches.

DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3.3 tons of LAr contained in a spherical acrylic vessel. At WIMP mass of 100 GeV, DEAP-3600 has a projected sensitivity of 10^-46 cm² for the spin independent elastic scattering cross section of WIMPs. Radioactive sources have been used for the energy calibration and to test the detector performance. One of the most effective calibration run has been taken with a ²²Na source deployed in a tube located around the DEAP-3600 steel shell. The simultaneous emission of three γs by the source provides an excellent tagging for the ²²Na decay. The results concerning the energy response of the detector and the agreement between data and Monte Carlo simulations in DEAP-3600 are investigated in this study.

The TREX-DM detector, a low background chamber with microbulk Micromegas readout, was commissioned in the Canfranc Underground Laboratory (LSC) in 2018. Since then, data taking campaigns have been carried out with argon and neon mixtures, at different pressures from 1 to 4 bar. By achieving a low energy threshold of 1 keV_ee and a background level of 80 counts keV^-1 kg^-1 day^-1 in the region from 1 to 7 keV_ee, the experiment demonstrates its potential to search for low-mass WIMPs. Two of the most important challenges currently faced are the reduction of both, background level and energy threshold. With respect to the energy threshold, recently a new readout plane is being developed, based on the combination of Micromegas and GEM technologies, aiming to have a pre-amplification stage that would permit very low energy thresholds, close to the single-electron ionization energy. With respect to the background reduction, apart from studies to identify and minimize contamination population, a high sensitivity alpha detector is being developed in order to allow a proper material selection for the TREX-DM detector components. Both challenges, together with the optimization of the gas mixture used as target for the WIMP detection, will take TREX-DM to explore regions of WIMP's mass below 1 GeV c^-2.

Liquid Ar (LAr) and liquid Xe (LXe) time projection chambers (TPCs) are used for many applications in neutrino physics and direct dark matter searches. The performance of these detectors, particularly dual-phase ones, depends very strongly on the efficiency for detecting the far ultraviolet (FUV) scintillation light. Such detection is particularly challenging for LAr, in which the strongest scintillation feature is observed at a wavelength of 127 nm (175 nm for LXe). The current mainstream approach is covering the optical surfaces with a wavelength shifter, which absorbs de FUV light and emits at wavelengths that overlap with the optical band, where commercial devices have higher detection efficiency. This work presents coatings designed to enhance the optical properties of the detector materials and to be an alternative to the current technique. In particular, two possible coatings are proposed: narrowband and broadband FUV reflective coatings. The narrowband coatings are tuned at the FUV scintillation light. They provide a large reflectance at the design angle; additionally, these coatings are naturally transparent at longer wavelengths, which might be useful to selectively detect the wavelength of interest. Their performance is evaluated taking into account the refractive index of LAr and as a function of the angle of incidence. The same calculations are performed for an aluminium-based broadband mirror. Finally, the effect on reflectance of submerging both sorts of mirrors at liquid nitrogen temperature is presented.

A novel Data Acquisition (DAQ) system, known as Level-1 Data Scouting (L1DS), is being introduced as part of the Level-1 (L1) trigger of the CMS experiment. The L1DS system will receive the L1 intermediate primitives from the CMS Phase-2 L1 trigger on the DAQ-800 custom boards, designed for the Phase-2 central DAQ. Firmware is being developed for this purpose on the Xilinx VCU128 board, with features similar to one half of the DAQ-800, and validated in a demonstrator for LHC Run-3. This contribution describes the firmware development in view of the target design for the DAQ-800.

The precision measurement of K⁺ → π⁺νν̅ at the NA62 experiment requires a kaon identification detector to have a time resolution better than 100 ps, at least 95 % kaon identification efficiency, and a pion misidentification probability of less than 10^-4. Since the start of NA62 data taking in 2016, kaon identification has been performed by a differential Cherenkov with achromatic ring focus (CEDAR) detector with a nitrogen gas radiator. A new CEDAR using hydrogen (CEDAR-H) as a radiator gas has been developed to reduce the material in the beamline, reducing the beam particle scattering within the detector. CEDAR-H was validated during a two-week test beam at CERN in 2022 and was approved by the NA62 collaboration for use in data taking from 2023. The test beam results, installation and commissioning in the NA62 beamline are reported.

An archaeometric study was carried out on thirteen of the thirty ancient Roman coins found in the "Grotta delle Ninfe" in Cerchiara di Calabria, Calabria, Italy. The coins are exhibited at the Brettii and Enotri Museum in Cosenza, Calabria. Due to their exposure to sulfur-rich water sources near the excavation site, these coins have deteriorated. The inscriptions are entirely unreadable due to a thick coating of corrosion products that have accumulated. This study aims to summarize the results obtained in previous works, including identifying the constituent elements, revealing hidden inscriptions that may help restore readability, and establishing the coin creation period and place.

A reliable and cost-effective interconnect technology is required for the development of hybrid pixel detectors. The interconnect technology needs to be adapted for the pitch and die sizes of the respective applications. This contribution presents recent results of a newly developed in-house single-die interconnection process based on Anisotropic Conductive Adhesives (ACA). The ACA interconnect technology replaces solder bumps with conductive micro-particles embedded in an epoxy layer applied as either film or paste. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACA using a flip-chip device bonder. The ACA technology can also be used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. A specific pixel-pad topology is required to enable the connection via micro-particles and create cavities into which excess epoxy can flow. This pixel-pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) process. The ENIG and ACA processes are qualified with a variety of different ASICs, sensors, and dedicated interconnect test structures, with pad diameters ranging from 12 μm to 140 μm and pitches between 20 μm and 1.3 mm. The produced assemblies are characterized electrically, with radioactive-source exposures, and in tests with high-momentum particle beams. This contribution introduces the developed interconnect and plating processes and showcases different hybrid assemblies produced and tested with the above-mentioned methods. A focus is placed on recent optimization of the plating and interconnect processes, resulting in an improved plating uniformity and interconnect yield.

One of the devices for generating circularly polarized radiation is a helical undulator in which a relativistic charged particle moves along a helical trajectory. In this paper, the spatial distribution of the electromagnetic field produced by such a particle is analyzed using electric field lines. The equations of electric field lines, which, due to the presence of curvature and torsion in the trajectory are precisely solved. A special algorithm for erasing invisible parts of the lines has been developed to represent the lines in space. Several remarkable features of the field picture are revealed, in particular, the hard component of the radiation is concentrated in the plane orthogonal to the undulator axis and passing through the position of the particle at the current moment of time.

Ancient documents are important historical sources that are often found in a fragmented condition due to their conservation status. In this study, we examined fragments of paper found in 1996 during excavation of the Santi Quattro Coronati complex, in Rome. The archaeological site where the fragments were found is situated on the first floor of the tower within the complex. This location was used as a disposal pit approximately between the 15th and 16th centuries. The fragments exhibit text discoloration, hindering automatic recognition and human readability. To reveal the faded text, the fragments have been digitalized, converted into a perceptually uniform color space and the contrast has been enhanced. The photometric characteristics of the input and enhanced images have been statistically characterized, and the contrast enhancement assessed by a state-of-the-art metric. The statistical analysis of the text colour coordinates was carried out to develop supervised and unsupervised image segmentation, isolating the text. The results of the method show that it effectively identifies text regions within images, improving readability, even for faded text. It can be integrated into deep learning-based character recognition systems, facilitating the automatic analysis of historical handwritten documents.

We investigate the quasi-coherent radiation from a train of electron bunches moving along the axis of a cylindrical waveguide, assuming that a part of the waveguide is filled with a dielectric medium. For the permittivity of the latter, the general case of dispersion is considered. It is shown that under certain conditions on the permittivity of the medium and on the values of the problem parameters, the waveguide modes become equidistant. As a consequence, quasi-coherent Cherenkov radiation from the train of bunches may be generated on the first several waveguide modes simultaneously. An example of dispersion law is provided for which the corresponding Cherenkov radiation is suppressed.

We present a novel cryogenic VUV spectrofluorometer designed to characterize wavelength shifters (WLS) crucial for experiments based on liquid argon (LAr) scintillation light detection. Wavelength shifters like 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) or polyethylene naphthalate (PEN) are used in these experiments to shift the VUV scintillation light to the visible region. Precise knowledge of the optical properties of the WLS at liquid argon's temperature (87 K) and LAr scintillation wavelength (128 nm) is necessary to model and understand the detector response. The cryogenic VUV spectrofluorometer was commissioned to measure the emission spectra and relative wavelength shifting efficiency (WLSE) of samples between 300 K to 87 K for VUV (120 nm to 190 nm) and UV (310 nm) excitation. New mitigation techniques for surface effects on cold WLS were established. As part of this work, the TPB-based wavelength shifting reflector (WLSR) featured in the neutrinoless double-beta decay experiment LEGEND-200 was characterized. The WLSE was observed to increase by (54 ± 5) % from room temperature (RT) to 87 K. PEN installed in LEGEND-200 was also characterized, and a first measurement of the relative WLSE and emission spectrum at RT and 87 K is presented. The WLSE of amorphous PEN was found to be enhanced by at least (37 ± 4) % for excitation with 128 nm and by (52 ± 3) % for UV excitation at 87 K compared to RT.

In the present work, we describe a new cryogenic setup for studies of wavelength-shifting materials for optimised light collection in noble element radiation detectors, and discuss the commissioning results. This SiPM-based setup uses α induced scintillation in gaseous argon as the vacuum ultraviolet light source with the goal of characterising materials, such as polyethylene naphthalate (PEN) and tetraphenyl butadiene (TPB), in terms of their wavelength-shifting efficiency. Preliminary results obtained with the system are consistent with the ones reported in literature: 0.5±0.05 in terms of WLS efficiency (PEN/TPB). A value of 1.24 μs was obtained for the triplet lifetime in Ar, which is a factor of 2.6 smaller than the one described in literature due to the presence of impurities. Further extensions of the system are currently being studied. The foreseen upgrades are expected to allow the study of GEM-like structures potentially interesting for rare-event searches. The design of the setup will be addressed along with the first results.

The paper reports experimental results demonstrating some properties of microfocus radiation generated in narrow internal silicon (Si) and tantalum (Ta) targets of the B-18 betatron with electron energy of 18 MeV. The targets were 50-μm- and 8-μm-thick Si crystals and a 13-μm-thick Ta foil oriented with a goniometer along the inner electron beam. The results showed strong dependence of the radiation beam shape on the orientation of the target relative to the electron beam, and on the target material. The resolution and contrast dependences of the Duplex IQI standard wire pair images on the position of the pairs in the radiation beam and on the target material are shown. The obtained results revealed the role of absorption and refraction of radiation in generation of magnified images of plastic and metal plate edges. Radiation generated in the Ta target showed high detection sensitivity for narrow gaps and thin inclusions in steel thickness.

Polyethylene naphthalate (PEN) foils have been demonstrated as a wavelength shifter suitable for operation in liquid argon. At the same time, wavelength shifting efficiency of technical grades of PEN, commercially available on the market, is lower than that of tetraphenyl butadiene (TPB). This paper reports on an R&D program focused on exploring the intrinsic limitations of PEN and optimizing it for the highest achievable wavelength shifting efficiency.

The study explores the application of catastrophe theory to describe the molecular mechanisms of smectisation and the regulation of polymorphism in nematic liquid crystal (NLC) systems. We propose a new approach for describing the stable and unstable states of NLC systems that induce the smectic (Sm) phase. A relation between the control variables of the cusp catastrophe and the Sm order parameter in NLC systems has been identified. The equilibrium states of the Sm phase are determined within the framework of catastrophe theory. By applying catastrophe theory to study the thermodynamic potential of an NLC system, we provide a detailed description of how the functional potential geometry changes depending on the control variables. The local geometry around the extremes of the functional thermodynamic potential allows for controllable catastrophes.

We present in this paper a new sensor called PICMIC-0 that is intended to exploit the intrinsic spatial resolution of the MicroChannel Plate (MCP) detectors. Manufactured using 6-metal TowerJazz 180 nm wafer technology, the sensor features hexagonal charge collection pixels on the top metal layer with a pitch of 5 μm and covering an area of 7.4 × 6.4 mm². The 2 million of the pixels of this sensor are not read out individually. Each pixel is connected to a straight-line in either 0°, 120° or -120° orientation, in which a current is produced in case of a hit. Each of these readout strip-lines is connected to a readout cell which receives this current, amplifies it using a current mirror and converts it into a digital signal by means of a current comparator. The data is collected from the digital outputs of the readout cells using a priority encoder readout scheme and transmitted in frames of 400 ns. This projective readout system reduces the number of channels to be read out from 2 million pixels to 2556 readout cells integrated within the pixel matrix. Using three projections reduces the ambiguity in case of multiple hits.

Intraband linear and nonlinear optical absorption in a strongly oblate lens-shaped Ge/Si quantum dot in the presence of an axial magnetic field was theoretically studied. Quantum transitions are considered in the heavy hole subband, when the scalar effective mass approximation is correct. The linear and nonlinear absorption coefficients, refractive index changes and the second harmonic generation coefficient were determined. The influence of the effects of temperature, size quantization and magnetic field on the behavior of the above parameters was revealed.

DarkSide-20k is a global direct dark matter search experiment situated underground at LNGS (Italy), designed to reach a total exposure of 200 tonne-years nearly free from instrumental backgrounds. The core of the detector is a dual-phase Time Projection Chamber (TPC) filled with 50 tonne of low-radioactivity liquid argon. The entire TPC wall is surrounded by a gadolinium-loaded polymethylmethacrylate (Gd-PMMA), which acts as a neutron veto, immersed in a second low-radioactivity liquid argon bath enclosed in a stainless steel vessel. The neutron veto is equipped with large-area Silicon PhotoMultiplier (SiPM) array detectors, placed on the outside of the TPC wall. SiPMs are arranged in a compact design meant to minimize the material used for PCBs, cables and connectors: the so-called Veto Photon-Detector Units (vPDUs). A vPDU comprises 16 vTiles, each containing 24 SIPMs, together with front-end electronics, and a motherboard, which distributes voltage and control signals, sums vTiles channels, and drives the electrical signal transmission. The neutron veto will be equipped with 120 vPDUs. The paper will focus on the production of the first vPDUs, describing the assembly chain in the U.K. institutes, in order to underline the rigorous QA/QC procedures, up to the final characterization of the first completed prototypes. Tests will be extensively performed in liquid nitrogen baths either for the single vTiles and for the assembled vPDUs, with the purpose of assigning a "quality passport" to each component.

An initial characterization of the BigRock high-speed, low-power Analog Front End (AFE) is presented. The BigRock AFE previously described in [1] has been refined in a second generation testbed ASIC, Pebbles. The AFE utilizes a current-mode signal path that has been designed for 4D tracking applications with precision time resolution of order 50 ps. The preamplifier concept is based on a prior art current-feedback CMOS topology in [2]. An on-chip test bench comprised of a variable injection circuit and high-resolution TDC measures the AFE timing resolution. An array of integrated load capacitors and IO IPs enhance the characterization capability. These full-custom pads include LVDS and clock receivers, CML output driver, and simple analog buffer pads designed at the process core voltage (0.9 V) on a 90 μm/180 μm pitch. Critical noise and timing metrics for an array of input detector capacitance ranging 0 to 100 fF have been measured.

The LHCb collaboration proposes a Phase-II Upgrade of the detector, to be installed during the LHC Long Shutdown 4 (2032–2034). Operating in the HL-LHC environment poses significant challenges to the design of the upgraded detector, and in particular to its tracking system. The primary and secondary vertices reconstruction will become more difficult due to the increase, by a factor of 7.5, of the average number of interactions per bunch crossing. The performance of the VErtex LOcator (VELO), which is the tracking detector surrounding the interaction region, is essential to the success of this Phase-II Upgrade. Data rates are especially critical for the LHCb full software trigger, and with the expected higher particle flux, the VELO Upgrade-II detector will have to tolerate a dramatically increased data rate: assuming the same hybrid pixel design and detector geometry, the front-end electronics (ASICs) of the VELO Upgrade-II will have to cope with rates as high as 8 Ghits/s, with the hottest pixels reaching up to 500 khits/s. With this input rate, the data output from the VELO will exceed 30 Tbit/s, with potentially a further increase if more information is added to the read-out. This paper outlines the challenges being addressed and the solutions under investigation for reading out the VELO sub-detector.

This contribution describes the characterisation and validation campaign of the prototype of the CMS Readout Chip (CROC), a 65 nm CMOS pixel readout ASIC for the CMS Inner Tracker upgrade for High Luminosity LHC. This validation campaign includes tests with single-chip and multi-chip modules, irradiation campaigns, test beams and wafer-level tests. The main results obtained in the testing of the CROC prototype will be outlined. Key improvements and fixes that have been implemented in the final version of the chip before the October 2023 submission will be described.

The Super-FRS at the FAIR accelerator complex will adopt Chemical Vapor Deposition diamond detectors as radiation-hard particle rate counters. Their role will be to monitor the beam transmission for beams with ions rates up to 10⁷ ions/spill and to calibrate the other beam diagnostics devices that are in duty at higher beam intensities. The target vacuum chamber of the Super-FRS hosts a 7 × 7 mm² single crystal diamond and a 25 × 25 mm² polycrystalline diamond: they are required to detect crossing particles with high efficiency (> 98%) in the case of heavy ion species (Ar to U), and to stand for several years in an environment in which they can potentially accumulate a dose of a few MGy per year. Laboratory measurements and beam test campaigns were arranged in the past years for the validation of the proposed sensors, in particular for the case of the polycrystalline technology. Here we report the outcome of the irradiation of a sensor based on a 20 × 20 mm² polycrystalline diamond produced by Element Six, with high intensity 1 GeV/nucleon Pb and U beams at GSI (Darmstadt). The detector signal shape characteristics and the ion counting efficiency have been monitored by interleaving periods of low ions rates, to evaluate possible damages or performance degradation during and after a total bombardment of about 6 × 10¹¹ heavy ions.

For the Phase-II upgrade of the ATLAS Muon Spectrometer to High-Luminosity LHC, new front-end readout electronics for the Monitored Drift Tube chambers is required, as the old one no longer meets the demands. The first stage in the Monitored Drift Tubes readout chain is the Amplifier-Shaper-Discriminator chip. For the upgrade, the new ASD2 ASIC chip in IBM 130 nm CMOS technology has been developed. For the ATLAS experiment, 80000 ASD2 chips are produced, which have to be tested before integration in order to obtain the required 50000 well-performing chips in the end. Using a prototype tester board and pre-production ASD2 chips, the overall performance and the influence on programmable parameters is investigated. Based on these results, 1775 production chips are tested to define final optimized cut values for the automated production testing of all chips in the company.

For the high-luminosity upgrade of the ATLAS Inner Tracking detector of the ATLAS experiment, a new pixel detector will be installed to allow for a bigger bandwidth and cope with the increased radiation among other challenges. This contribution will present the evaluation of the Outer Barrel Pixel layer services chains. A full data transmission study covering data merging will be presented from the pixel module all the way to the FELIX data acquisition system, using most of the components foreseen for the detector. Challenges and results of the services chain of the Outer Barrel will be highlighted.

The motion of charged particles in a crystal in the axial channeling regime can be both regular and chaotic. The chaos in quantum case manifests itself in the statistical properties of the energy levels set. These properties have been studied previously for the electrons channeling along [110] direction of the silicon crystal, in the case when the classical motion was completely chaotic, as well as for the ones channeling along [100] direction, when the classical motion can be both regular and chaotic for the same energy depending on the initial conditions. Here we study the positrons channeling in [100] direction. This case is of special interest due to the substantial tunneling probability between dynamically isolated regular motion domains in the phase space. The interaction of the energy levels via tunneling distinctly changes the level spacing statistics. All transverse motion energy levels as well as corresponding stationary wave functions are computed numerically for the 30 GeV positrons channeling in [100] direction of the silicon crystal. The values of the matrix elements for the tunnel transitions are extracted from these data. These results confirm the chaos assistance for the tunneling and the level splitting. These values will be used in the further researches of the quantum chaos manifestations in the channeling phenomenon.

The character of motion (regular or chaotic) on the quantum level manifests itself in the statistics of the set of the system's energy levels. The completely regular case generates the sequence of the levels with exponential (Poisson) level spacing distribution; the completely chaotic one — with Wigner distribution. The most interesting case is the co-existence of the regular and chaotic motion domains in the phase space of the system under consideration. The assumption of independent generation of two level sequencies by one chaotic domain and by all regular domains leads to Berry-Robnik distribution. However, the presence of the chaotic motion domain in the phase space affects the levels produced by the regular domains via the so-called chaos-assisted tunneling (CAT) that leads to Podolskiy-Narimanov distribution of the level spacings. This distribution needs the mean amplitude of the tunnel transition and the relative contribution of the regular domains to the mean level density as the parameters. Using their estimations for the transverse motion of the high energy positrons channeling near [100] direction in the silicon crystal we found that Podolskiy-Narimanov distribution demonstrates the best agreement with the level spacing distribution.

After exploring different solutions and testing several options, the high granularity resistive Micromegas technology is now mature enough to offer an efficient operation up to particle rates of 10 MHz/cm², maintaining the gas amplification above 10⁴, with a large margin before breakdown in order to ensure a stable and reliable operation. The detector exploits small-size readout pads for occupancy reduction and a double Diamond-Like Carbon (DLC) resistive layer with a network of dot-connections to ground for a fast charge evacuation. The double-layer allows preserving the minimum resistance to suppress the discharge intensity for stable operations. The performance measured with particle beams at CERN have shown a spatial resolution below 100 μm for mm-wide readout pads and a few ns time resolution. Now, the technology is being scaled to larger areas, with the construction of detectors with an active area of ∼20×20 cm² (already achieved) and new ∼40×50 cm² prototypes under construction. An overview of the detector technology, including the latest results, is presented in terms of the gain and rate capability (measured in the laboratory) and efficiency, time and spatial resolution (measured at the CERN SPS). Possible applications in HEP experiments, as well as future developments, are also reported.

An accurate determination of the band gap energy is crucial for predicting the photophysical and photochemical properties of investigated materials. In the present work, the dependence of the energy band gap (E_g) of α-LiIO₃ crystals doped with L-arginine and L-nitroarginine amino acids was obtained. The method, based on the simultaneous fitting of many absorption mechanisms to the spectral dependence of the Kubelka-Munk function estimated from diffuse reflection data, as well as Tauc's method, has been applied to determine the energy band gap. In the case of a small dopant concentration, additional electron states appear within the band gap of the crystals. As a result, a broad absorption band appears in the material spectrum. The optical transmittance spectra were recorded using an Agilent Cary 60 spectrophotometer in the spectral range 190–1100 nm.

The LHC upgrade requires redoing the liquid Argon (LAr) calibration system which should provide a 16-bit range signal with 1‰ accuracy while being radiation tolerant. The fundamental operating principle remains unchanged: a precise current is stored in an inductor, and upon switching off the current, a pulse is generated for injection into the readout electronics. This is achieved by two chips: the first one, in CMOS 130 nm, provides the 16-bit DAC as well as the calibration management system; the second one, in XFAB 180 nm, embeds switches to generate the pulses. A description of both chips and measurement results will be presented.

Argon gas doped with 1% wavelength-shifter (CF₄) has been employed in an optical time projection chamber (OTPC) to image cosmic radiation. We present results obtained during the system commissioning, performed with two stacked glass thick gaseous electron multipliers (THGEMs) and an electron-multiplying charge coupled device (EMCCD camera) at 1 bar. Preliminary estimates indicate that the combined optical gain was of the order of 10⁶ (ph/e), producing sharp and high-contrast raw images without resorting to any filtering or post-processing. A first assessment of the impact of pressurization showed no change in the attainable gains when operating at 1.5 bar.

The Barrel of γ array, consisting of 640 CsI(Tl) crystals and covering a polar angle range from 36.4° to 135.6°, has been designed for the experimental terminals at High energy FRagment Separator of High-Intensity heavy-ion Accelerator Facility in Huizhou. Together with the existing Endcap, consisting of 1024 CsI(Tl) crystals and covering a polar angle from 15.6° to 36.4°, at the External Target Facility in Lanzhou to form a new γ array, it is expected to meet the experimental requirements for in-beam γ-ray spectroscopy technique. A Monte Carlo code based on Geant4 was implemented to study the performance of the new γ array. Taking into account the Doppler correction and the intrinsic energy resolution of the detector, the energy resolution is 5.4% (FWHM) for the Endcap and 9.8% (FWHM) for the Barrel when the energy of the emitted  γ-ray is 1 MeV in the Center-of-Mass frame with the beam energy of 500 MeV/u (beam velocity β = 0.759). The full-space photopeak efficiency is greater than 40% when the energy of the emitted γ-ray is less than 5 MeV in the Center-of-Mass frame and the beam energy is less than 700 MeV/u (β = 0.821). Such performance can satisfy most of the physics requirements for in-beam  γ-ray spectroscopy experiments.

Molten lead (Pb) and its alloys (PbBi and PbLi) are of immense interest for various nuclear engineering applications, including but not limited to advanced Lead-cooled Fast Reactors (LFRs), tritium Breeding Blankets (BBs) of fusion power plants and spallation targets for Accelerator-Driven Systems (ADS). Owing to their attractive thermophysical properties, these advanced fluids assert their candidacy to address the critical requirements of neutron multiplication, neutron moderation, high temperature coolants and tritium breeders, enabling the operation of next generation nuclear systems at high temperatures with better efficiencies. However, for numerous reasons such as a compromise of structural integrity at the heat transfer interface, presence of an inert cover gas during charging of molten metal in the loop, and the fusion fuel cycle itself may lead to molten metal-gas two-phase flows with high density ratios. At present, no effective diagnostics exist to detect such operational and accidental occurrences in high temperature molten metal systems resulting in a severe lack of relevant experimental studies. To address these limitations and to advance the current understanding toward two-phase regimes in high temperature Pb-based melts, the present work focuses on the design and assembly aspects of an electrical conductivity-based two-phase detection sensor array, utilizing high purity  α-Al₂O₃ coatings with AlPO₄ binder as electrical insulation layers. This paper discusses the design considerations, thermal analysis, systematic selection of structural/functional components along with preliminary results from the probe performance tests in very high temperature (600°C) static molten Pb column for real time detection of argon gas bubbles rising within the melt. Quantitative estimations of time-averaged void fraction, average bubble impaction frequency and average bubble residence time are presented from the preliminary experimental investigations.

Based on the design requirements proposed by the Beijing On-Line Isotope Separation project (BISOL), four Sn²²⁺-based, 81.25 MHz continuous wave (CW) drift tube linac (DTL) cavities have been designed. These DTLs are capable of accelerating Sn²²⁺ of 0.1 pmA from 0.5 MeV/u to 1.8 MeV/u over a length of 7 m, with an output longitudinal normalized RMS emittance of 0.35π·mm·mrad, and transmission efficiency higher than 95%. The dynamics design adopted the KONUS (Kombinierte Null Grad Struktur Combined 0° Structure) scheme. Comprehensive error study implies that these DTLs can accommodate a wide range of non-ideal beams and cavity alignment errors while maintaining high transmission efficiency. The electromagnetic design employed a Cross-bar H-mode (CH) structure for superior water-cooling characteristics, and a detailed tuning analysis was conducted to derive an optimal tuning scheme. The results of the multiple-physics analysis indicate that the frequency shift of each cavity is within an acceptable range. Comparing the dynamics requirements with the RF design results, similar particle output phase distribution, equivalent energy gain and consistent emittance growth are observed. Detailed designs will be presented in this manuscript.

The High Luminosity (HL-LHC) project aims to increase the integrated luminosity of CERN's Large Hadron Collider (LHC) by an order of magnitude compared to its initial design. This requires a large increase in bunch intensity and beam brightness compared to the first three LHC runs, and hence poses serious collective-effects challenges, related in particular to electron cloud, instabilities from beam-coupling impedance, and beam-beam effects. Here, we present the associated constraints and the mitigation measures proposed to achieve the baseline performance of the upgraded LHC machine. We also discuss the interplay of these mitigation measures with other aspects of the accelerator, such as optics, physical and dynamic apertures, the collimation system, and crab cavities. Additional potential sources of intensity limitations are also briefly discussed.

This article focuses on the current status of the dipole magnet power supply (DMPS) and improvement in the Taiwan Photon Source (TPS) storage ring. The DMPS provides a stable and precise magnetic field for the storage ring operation. Appropriate wiring methods are employed to minimize magnetic field interference across the entire TPS area to meet the demands of high-energy output and overcome the challenges of operating at high currents. The target energy is set at 850 V and 750 A, utilizing a single-pole switching voltage regulator as a high-precision constant current source output structure. The system incorporates a closed control loop that uses the Direct Current Current Transducer (DCCT) to provide current signal feedback to the system. FPGA (Field-Programmable Gate Array) calculates PID (Proportional-Integral-Derivative) compensation values, generating a 2.1 kHz pulse width modulation (PWM) signal to regulate the output current. At the same time, insulated gate bipolar transistor (IGBT) modules are switching components. However, even after several years of practical operation, the stability and performance of the DMPS in the storage ring still require improvements. To enhance long-term output current stability and address peripheral issues, the current TPS utilizes the Beam Orbit Feedback (FOFB) system to suppress and fine-tune the magnetic field and compensate for the impact of temperature drift on the DMPS's output current. This improvement ensures a more stable circulation of the photon beam within the storage ring. By optimizing the temperature control circuit of the main control card, the long-term output current stability has been successfully enhanced to within ± 10 ppm. Simultaneously, the FOFB system reduces uncertainties in adjusting the X-axis beam position, improving beam stability and quality. Furthermore, relevant protective measures have been implemented to ensure robust system operation. Ultimately, these improvement measures have successfully met TPS's stringent requirements for the DMPS, enabling the synchrotron accelerator light source to operate at higher performance levels and fostering advanced scientific research. The results of these upgrades underscore the success of the power supply enhancements, making significant contributions to the overall improvement of the Taiwan Photon Source facility.

This work is an effort to maximize the number of output neutrons of a photoneutron target for 100 MeV incident electrons. The work steps were; to select the appropriate material, select the appropriate shape, and find the optimized dimensions. The simulations of this work were done with MCNPX2.6 simulation code. At first, U-235 was selected as the best material for the target, among some heavy atoms from the number of outlet neutron point of view. Then the best shape for the target was selected from geometric shapes that have been considered for the target and the dimensions of the target were optimized. After these parts, the energy spectrum of outlet neutrons was estimated and after that, the deposited energy of neutrons, electrons, and photons in the target was estimated and drowned with Tec plot.

The Linear International Fusion Materials Irradiation Facility Prototype Accelerator (LIPAc) is under commissioning in Rokkasho Fusion Institute in Japan and aims to accelerate 125 mA D+ at 9 MeV in Continuous Wave mode for validating the IFMIF accelerator design. To ensure a fine characterization and tuning of the machine many beam diagnostics are installed spanning from injector to the beam dump. The beam operations in 1.0 ms pulsed D+ at 5 MeV were successfully completed with a low power beam dump in 2019. Despite the challenges posed by the pandemic, the crucial transition to a new LINAC configuration was also finalized to enable operation in 1.0 ms — CW D+ at 5 MeV with the high-power beam dump. The 1^st  beam operation of the configuration was carried out in 2021. The experiences and challenges encountered during these beam campaigns are described in this paper.

Ghana's 32-meter radio telescope, inaugurated in August 2017, was once a redundant telecommunications dish that underwent conversion. Prior to this transformation, feasibility studies were conducted to assess the dish's structural integrity, technical compatibility, and economic viability. These studies aimed to determine if the conversion project could be technically achieved given the available technology, expertise, and resources. This paper delves into the engineering considerations surrounding structural, mechanical, software, control and monitoring, radio frequency, and timing frequency reference requirements that distinguish the operation of a radio telescope from its former role as a satellite earth station. Significant components such as the azimuth bearing, sub-reflector support, cable wrap, and electrical motors underwent replacement. Additionally, a new C-band receiver, radio frequency controller, active hydrogen maser timing frequency, and software were developed. Testing protocols to meet science requirements for both single-dish observations and Very Long Baseline Interferometry (VLBI) are also discussed. The conversion process proved to be lengthy and encountered numerous unforeseen circumstances, yet it provided invaluable learning experiences for a developing country like Ghana.

The Facility for Rare Isotope Beams (FRIB) began operation with 1 kW beam power for scientific users in May 2022 upon completion of 8 years of project construction. The ramp-up to the ultimate beam power of 400 kW, planned over a 6-year period, will enable the facility to reach its full potential for scientific discovery in isotope science and applications. In December 2023, a record-high beam power of 10.4 kW uranium was delivered to the target. Technological developments and accelerator improvements are being made over the entire facility and are key to completion of the power ramp-up. Major technological developments entail the phased deployment of high-power beam-intercepting systems, including the charge strippers, the charge selection systems, the production target, and the beam dump, along with support systems, including non-conventional utilities (NCU) and remote handling facilities. Major accelerator improvements include renovations to aging legacy systems associated with experimental beam lines and system automation for improved operational efficiency and better machine availability. Experience must be gained to safely handle the increased radiological impacts associated with high beam power; extensive machine studies and advanced beam tuning procedures are needed to minimize uncontrolled beam losses for the desired operating conditions. This paper discusses the technological developments and accelerator improvements with emphasis on major R&D efforts.

Operation of the Large Hadron Collider (LHC) requires strong octupolar magnetic fields to suppress coherent beam instabilities. The amplitude detuning that is generated by these octupolar magnetic fields brings the tune of individual particles close to harmful resonances, which are mostly driven by the octupolar fields themselves. In 2023, new optics were deployed in the LHC at injection with optimized betatronic phase advances to minimize the resonances from the octupolar fields without affecting the amplitude detuning. This paper reports on the optics design, commissioning, and lifetime measurements performed to validate the optics.

The accelerator complex of China Spallation Neutron Source (CSNS) consists of an 80 MeV H^- Linac and a 1.6 GeV proton rapid cycling synchrotron (RCS). The beam injection is one of the most important issues for the CSNS accelerator complex. In this paper, the injection methods have been comprehensively studied, including phase space painting and H^- stripping. By using the design scheme of the anti-correlated painting, the beam power has successfully reached 50 kW. However, some difficulties have been found in the higher power beam commissioning. In order to solve these key problems, flexibility in the CSNS design has been exploited to implement the correlated painting by using the rising current curve of the pulse power supply. The effectiveness of the new method has been verified in the simulation and beam commissioning. By using the new method, the beam power on the target has successfully risen to the design value. Secondly, according to the CSNS beam commissioning experience, based on the present design of the injection system, a new idea is proposed to perform both correlated and anti-correlated painting in the CSNS. By adopting an additional vertical shift bump generated by four additional alternating current (AC) magnets in the injection region, the local orbit can be manipulated to meet the requirement of correlated painting. The new method can not only perform the correlated painting, but also optimize the anti-correlated painting. The simulation study shows that the new method works well, and both correlated and anti-correlated painting methods are well performed.

It is common in the accelerator community to use the impedance of accelerator components to describe wake interactions in the frequency domain. However, it is often desirable to understand such wake interactions in the time domain in a general manner for excitations that are not necessarily Gaussian in nature. The conventional method for doing this involves taking the inverse Fourier Transform of the component impedance, obtaining the Green's Function, and then convolving it with the desired excitation distribution. This method can prove numerically cumbersome, for a convolution integral must be evaluated for each individual point in time when the wake function is desired. An alternative to this method would be to compute the wake function analytically, which would sidestep the need for repetitive integration. Only a handful of cases, however, are simple enough for this method to be tenable. One of these cases is the case where the component in question is an RLC resonator, which has a closed-form analytical wake function solution. This means that a component which can be represented in terms of resonators can leverage this solution. As it happens, common network synthesis techniques may be used to map arbitrary impedance profiles to RLC resonator networks in a manner the accelerator community has yet to take advantage of. In this work, we will use Foster Canonical Resonator Networks and partial derivative descent optimization to develop a technique for synthesizing resonator networks that well approximate the impedances of real-world accelerator components. We will link this synthesis to the closed-form resonator wake function solution, giving rise to a powerful workflow that may be used to streamline beam dynamics simulations.

The India-based Neutrino Observatory's (INO) Iron CALorimeter (ICAL) experiment will be instrumented with about 28,800 large area glass Resistive Plate Chambers (RPCs) as active detector elements. The mini-ICAL, which is a 600-times scaled-down prototype version of the ICAL, is currently in operation at the Inter Institutional Centre for High Energy Physics (IICHEP), a transit campus of the INO project in Madurai, India. The 4 m×4 m detector comprises an ∼ 85 t magnet, built using 11 layers of iron plates to accommodate 10 layers of RPCs — two RPCs per layer. A closed-loop gas system (CLS) is designed to supply gas mixture of R134a (95.2%), isobutane (4.5%), and SF₆ (0.3%) to the mini-ICAL, collect the return gas from the RPCs, purify it using filters, and recirculate the mixture into the detector. Contamination of any kind into the gas mixture will severely affect the characteristics of the RPC detectors, such as the dark current and noise rates, and consequently deteriorate performance of the RPC detector. The contamination is mainly caused due to leaks within the gas system, in the gas lines and in the RPC gas gap volume. This paper deals with systematic identification and mitigation of leaks within the closed-loop gas system and performance improvement of the RPCs installed in the mini-ICAL detector.

The SPIRAL2 linac is now successfully commissioned; H⁺, ⁴He²⁺, D⁺ and ¹⁸O⁶⁺ have been accelerated up to nominal parameters and ¹⁸O⁷⁺ and⁴⁰Ar¹⁴⁺ beams have been also accelerated up to 7 MeV/A. The main steps with 5 mA H⁺, D⁺ beams and with 0.6 mA ¹⁸O⁶⁺ are described. The general results of the commissioning of the RF, cryogenic and diagnostics systems, as well as the preliminary results of the first experiments on NFS are presented. In addition of an improvement of the matching to the linac, the tuning procedures of the 3 Medium Energy Beam Transport (MEBT) rebunchers and 26 linac SC cavities were progressively improved to reach the nominal parameters in operation, starting from the classical "signature matching method". The different cavity tuning methods developed to take into account our particular situation (very low energy and large phase extension) are described. The tools developed for an efficient linac tuning in operation, e.g. beam energy and intensity changes are also discussed.

The PocketWATCH facility is a unique multi-purpose test bed designed to replicate the conditions of large water Cherenkov detectors. Housed at the University of Sheffield, the facility consists of a light-tight 2000 L ultrapure water tank with purification and temperature control systems. Water temperature, resistivity, and UV attenuation in the tank are monitored and shown to be stable over time. The system is also shown to be compatible with a solution of 0.2% gadolinium sulfate, allowing further utility in testing equipment bound for the next generation neutrino and nucleon decay water Cherenkov particle detectors. The relevant water quality parameters are shown to be stable whilst running in Gd-mode, thereby providing a suitable test bed for hardware development in a realistic, ex situ environment.

Taiwan Photon Source (TPS) is a globally renowned 3 GeV synchrotron accelerator light source. With a successful decade of operation, various subsystems have continuously improved and maintained an optimal research facility environment. Presently, there is a concerted effort towards energy conservation. This technical report focuses on the future development of the TPS-II Permanent Magnet Trim Coil Power Supply for the correction magnet, emphasizing a Bipole high-current correction magnet power source. According to the prototype specifications, the maximum output current is 20 A with an operating voltage of 48 V. This augmentation increases the amplitude of the magnetic field correction in the permanent magnet-associated Trim core, providing greater flexibility in manufacturing the permanent magnet correction coils. To design a power supply with high current and stability, the system adopts the Danisense DP50-IP-B DC Current Transducers (DCCT) as the current feedback component and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) as power switches in a full-bridge (H-bridge) configuration. The driving frequency is set at 40 kHz. Analog modulation control circuitry and protective circuits ensure precise control loop modulation. In the power laboratory, a hardware prototype circuit was constructed, featuring a 48 V input voltage, 20 A output current, a maximum power of 960W, and a current ripple component maintained within 100 μA. This experiment validates the control loop design of the prototype, showcasing the ability to achieve rapid and stable output current performance. Using a 1 V input reference signal for small-signal testing, the bandwidth displayed a -3 dB bandwidth of 8.51 kHz. Long-term current stability is within ± 10 ppm, and interface compatibility with the existing TPS correction magnet power source interface allows direct operation within the current system.

The Jiangmen Underground Neutrino Observatory is a neutrino experiment that incorporates 20,012 20-inch photomultiplier tubes (PMTs) and 25,600 3-inch PMTs. A dedicated system was designed to protect the PMTs from an implosion chain reaction underwater. As a crucial element of the protection system, over 20,000 acrylic covers were manufactured through injection molding, ensuring high dimensional precision, mechanical strength, and transparency. This paper presents the manufacturing technology, mass production process, and performance characteristics of the acrylic covers.

The Linear IFMIF Prototype Accelerator, LIPAc, is being commissioned aiming at validating the RFQ up to 5 MeV beam acceleration. Eventually, the nominal beam of 5 MeV–125 mA in 1 ms length and 1 Hz rate pulsed mode was achieved in 2019. The beam operation has been resumed since July 2023 after a long maintenance including recovery from unexpected problems in the RFQ-RF system. This new phase aims at the commissioning of the full configuration except SRF LINAC, which is replaced by a temporary beam transport line. Focusing on the RFQ behavior, it will be interesting to operate it at higher duty, especially for longer pulses. Furthermore, a beam simulation study suggested that the beam extracted from the RFQ includes considerable momentum halo when the vane voltage reduces by more than 5 %, with a slight decrease of the mean energy. It can be a potential source of a quench like the mismatched beam in the cryomodule. This could be studied by measuring the energy from the Time-of-Flight among multiple BPMs while monitoring beam loss around the dipole, where momentum halo should be lost. During the beam commissioning phase, we studied them by scanning the RFQ voltage.

The large area trigger detector is a key instrument in cosmic ray telescope system. One large area detector, sensitive size 1.3 ^* 2 m², is proposed in this paper based on plastic scintillator tiles and wavelength shift optical fibers. Thanks to the wavelength shift fibers coupling to the scintillator tiles, only one photomultiplier tube is used to output the signals for whole large area detector. So this detector is simple and economy. The signal uniformity of this detector is better than 96% over the whole surface including the edges or corners. The detection efficiency of the muon is higher than 95%, and the time resolution is better than 10 ns over the entire detector. These performances are sufficient for the trigger detector in most cosmic ray telescope system.