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Ultra‐high‐speed synchrotron‐based hard X‐ray (i.e. above 10 keV) imaging is gaining a growing interest in a number of scientific domains for tracking non‐repeatable dynamic phenomena at spatio‐temporal microscales. This work describes an optimized indirect X‐ray imaging microscope designed to achieve high performance at micrometre pixel size and megahertz acquisition speed. The entire detector optical arrangement has an improved sensitivity within the near‐ultraviolet (NUV) part of the emitted spectrum (i.e. 310–430 nm wavelength). When combined with a single‐crystal fast‐decay scintillator, such as LYSO:Ce (Lu2−xYxSiO5:Ce), it exploits the potential of the NUV light‐emitting scintillators. The indirect arrangement of the detector makes it suitable for high‐dose applications that require high‐energy illumination. This allows for synchrotron single‐bunch hard X‐ray imaging to be performed with improved true spatial resolution, as herein exemplified through pulsed wire explosion and superheated near‐nozzle gasoline injection experiments at a pixel size of 3.2 µm, acquisition rates up to 1.4 MHz and effective exposure time down to 60 ps. [ABSTRACT FROM AUTHOR]

Silicon photomultipliers (SiPMs) are solid-state single-photon-sensitive detectors that show excellent performance in a wide range of applications. In FBK (Trento, Italy), we developed a position-sensitive SiPM technology, called "linearly graded" (LG-SiPM), which is based on an avalanche-current weighted-partitioning approach. It shows position reconstruction resolution below 250 μm on an 8 × 8 mm2 device area with four readout channels and minimal distortions. A recent development in terms of LG-SIPM is a larger chip version (10 × 10 mm2) based on FBK NUV-HD technology (near-ultraviolet sensitive), with a peak photon detection efficiency at 420 nm. Such a large-area detector with position sensitivity is very interesting in applications like MR-compatible PET, high-energy physics experiments, and readout of time-projection chambers, gamma and beta cameras, or scintillating fibers, with a reduced number of channels. These SiPMs were characterized in terms of noise, photon detection efficiency, and position resolution. We also developed tiles of 2 × 2 and 3 × 3 LG-SiPMs, reaching very large sensitive areas of 20 × 20 mm2 and 30 × 30 mm2. We implemented a "smart-channel" configuration, which allowed us to have just six output channels for the 2 × 2 elements and eight channels for the 3 × 3 element tiles, preserving a position resolution below 0.5 mm. These kinds of detectors provide a great advantage in compact and low-power applications by maintaining position sensitivity over large areas with a small number of channels. [ABSTRACT FROM AUTHOR]

Liquid scintillator detectors have great advantages in the field of radionuclide detection because of their low detection limit, high sensitivity, and diverse functions. However, the material properties of liquid scintillators directly determine their detection effectiveness, which leads to their poor vertex resolution and particle identification. In this work, we introduce the improvement methods, choices, and properties of different novel liquid scintillator materials in recent years. This article is expected to provide references for the development and research of liquid scintillator materials in various application fields. [ABSTRACT FROM AUTHOR]

• CeBr 3 and NaI (Tl) scintillators characterized with array of Silicon Photomultipliers. • Energy resolution improves with lower shaping time and higher SiPM over-voltage. • Temperature dependency of gain of SiPM array: ∼−0.81 %/°C for overvoltage of 2.5 Volts. • Temperature dependency of light yield for CeBr 3 : ∼−0.27 %/°C for −31 °C to +26 °C. • Temperature dependency of light yield for NaI (Tl): ∼+0.5 %/°C for −31 °C to +26 °C. Interaction of X-rays with a scintillation detector produces optical photons in the visible range. The spectral and spatial information of the X-ray can be derived by detecting these output photons using a Silicon Photomultiplier (SiPM). Two types of detector modules: CeBr 3 and NaI (Tl), coupled with an array of SiPM are presented here, which are being developed for the future space exploration programs. The development of the front end electronics (FEE) for the charge readout from SiPM for X-ray spectrometer application is presented here which is characterized for SiPM's over-voltages and shaping amplifier's time constant. In this article, both the detector modules are subjected to a wide temperature range to establish a relationship of the SiPM's gain, energy resolution and scintillators' output photon yield with ambient temperature. The test results show that energy resolution improves with higher over-voltage of SiPM and also with lower operating temperature. The gain of the SiPM array shows negative temperature dependence of ∼−0.81 %/°C for an over-voltage of 2.5 Volts. To derive the temperature dependency of scintillators' output photons, gain of the SiPM array was made constant by operating it at a fixed over-voltage for a wide temperature range. With the constant gain of SiPM, CeBr 3 scintillator shows negative temperature coefficient of ∼−0.27 %/°C and NaI (Tl) shows positive temperature coefficient of ∼+0.5 %/°C for the light output in the temperature range of −31 °C to +26 °C. [ABSTRACT FROM AUTHOR]

Cone-beam computed tomography (CBCT) has emerged in recent years as an adequate alternative to mammography and tomosynthesis due to the several advantages over traditional mammography, including its ability to provide 3D images, its reduced radiation dose, and its ability to image dense breasts more effectively and conduct more effective breast compressions, etc. Furthermore, CBCT is capable of providing images with high sensitivity and specificity, allowing a more accurate evaluation, even of dense breasts, where mammography and tomosynthesis may lead to a false diagnosis. Clinical and experimental CBCT systems rely on cesium iodine (CsI:Tl) scintillators for X-ray energy conversion. This study comprises an investigation among different novel CBCT detector technologies, consisting either of scintillators (BGO, LSO:Ce, LYSO:Ce, LuAG:Ce, CaF2:Eu, LaBr3:Ce) or semiconductors (Silicon, CZT) in order to define the optimum detector design for a future experimental setup, dedicated to breast imaging. For this purpose, a micro-CBCT system was adapted, using GATE v9.2.1, consisting of the aforementioned various detection schemes. Two phantom configurations were selected: (a) an aluminum capillary positioned at the center of the field of view in order to calculate the system's spatial resolution and (b) a breast phantom consisting of spheres of different materials, such that their characteristics are close to the breast composition. Breast phantom contrast-to-noise ratios (CNRs) were extracted from the phantom's tomographic images. The images were reconstructed with filtered back projection (FBP) and ordered subsets expectation-maximization (OSEM) algorithms. The semiconductors acted satisfactorily in low-density matter, while LYSO:Ce, LaBr3:Ce, and LuAG:Ce presented adequate CNRs for all the different spheres' densities. The energy converters that are presented in this study were evaluated for their performance against the standard CsI:Tl crystal. [ABSTRACT FROM AUTHOR]

The overall gain of a scintillation detector is temperature-dependent, leading to a drift in the measured gamma energy spectrum with changes in temperature. To mitigate this effect, a temperature drift correction is essential prior to conducting gamma spectrum analysis. In this study, the detector gain ratio is determined by comparing the positions of the same background peak across different spectra. Subsequently, the original spectrum is adjusted accordingly to obtain a gamma spectrum free from temperature drift. Experimental results demonstrate that after implementing this correction, the relative deviation of the 57Co characteristic peak positions in the gamma spectrum measured by the NaI(Tl) detector is reduced from 18.64% to 0.91%. Furthermore, by performing energy calibration beforehand, the characteristic peak position can be utilized for secondary correction, further minimizing temperature drift. Our findings indicate that the relative deviation of the 22Na characteristic peak positions was reduced, respectively, to 0.51% and 0.46% through secondary correction. This approach, which utilizes the background peak for correction, avoids the need for additional radioactivity or circuitry and effectively mitigates peak drift. Overall, this method holds significant implications for enhancing the accuracy of gamma spectrum analysis. [ABSTRACT FROM AUTHOR]

We explored the nonlinear characteristics of energy resolution (ER) for the sealed NaI (Tl) scintillator detector by using a gamma-ray spectroscopy system and Monte Carlo simulation. Our research focused on the two primary factors of energy resolution including the photomultiplier tube (PMT) voltage and the distance between the gamma-ray sources (137Cs and 60Co) and the scintillator detector. The experimental results showed that energy resolution decreased when the PMT voltage increased, and the energy resolution of NaI (Tl) detectors reached a smaller value (6.92%, 6.76%, and 6.56%), especially with the PMT voltage in the range of 575–595 V. In addition, a suitable distance between the gamma-ray source and the scintillator (5 cm) can also effectively reduce the energy resolution. We established the simulation models of the experimental NaI (Tl) detectors and simulated their energy spectra. The simulation results in the peak area agreed with the experimental results. A possible better PMT voltage choice has been proposed to obtain a smaller energy resolution. [ABSTRACT FROM AUTHOR]

In recent years, indirect digital radiography detectors have been actively studied to improve radiographic image performance with low radiation exposure. This study aimed to achieve low-dose radiation imaging with a thick scintillation detector while simultaneously obtaining the resolution of a thin scintillation detector. The proposed method was used to predict the optimal point spread function (PSF) between thin and thick scintillation detectors by considering image quality assessment (IQA). The process of identifying the optimal PSF was performed on each sub-band in the wavelet domain to improve restoration accuracy. In the experiments, the edge preservation index (EPI) values of the non-blind deblurred image with a blurring sigma of σ = 5.13 pixels and the image obtained with optimal parameters from the thick scintillator using the proposed method were approximately 0.62 and 0.76, respectively. The coefficient of variation (COV) values for the two images were approximately 1.02 and 0.63, respectively. The proposed method was validated through simulations and experimental results, and its viability is expected to be verified on various radiological imaging systems. [ABSTRACT FROM AUTHOR]

Background: Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for constructing a Total-Body PET scanner based on plastic scintillators. Methods: For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configurations (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), different cross sections of plastic scintillator, and multiple numbers of plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Siemens' Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1 mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm. Results: With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance (∼ 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body with additional gain on its sides and provides the possibility for high-quality brain imaging. Conclusion: Taking into account not only the sensitivity but also the price of Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners. [ABSTRACT FROM AUTHOR]

This paper is devoted to the current status of the novel fully active 3D (three-dimensional) fine-grained scintillator detector SuperFGD as a main part of the near off-axis detector upgrade program for the T2K experiment. The following important components related to the SuperFGD such as SuperFGD electronics and mechanics, wavelength shifting (WLS) fibers, and light emitting diode (LED) calibration system are also discussed here as well as the detector's near future. [ABSTRACT FROM AUTHOR]

Background: Many computational methods have been developed to detect non-reference transposable element (TE) insertions using short-read whole genome sequencing data. The diversity and complexity of such methods often present challenges to new users seeking to reproducibly install, execute, or evaluate multiple TE insertion detectors. Results: We previously developed the McClintock meta-pipeline to facilitate the installation, execution, and evaluation of six first-generation short-read TE detectors. Here, we report a completely re-implemented version of McClintock written in Python using Snakemake and Conda that improves its installation, error handling, speed, stability, and extensibility. McClintock 2 now includes 12 short-read TE detectors, auxiliary pre-processing and analysis modules, interactive HTML reports, and a simulation framework to reproducibly evaluate the accuracy of component TE detectors. When applied to the model microbial eukaryote Saccharomyces cerevisiae, we find substantial variation in the ability of McClintock 2 components to identify the precise locations of non-reference TE insertions, with RelocaTE2 showing the highest recall and precision in simulated data. We find that RelocaTE2, TEMP, TEMP2 and TEBreak provide consistent estimates of ∼ 50 non-reference TE insertions per strain and that Ty2 has the highest number of non-reference TE insertions in a species-wide panel of ∼ 1000 yeast genomes. Finally, we show that best-in-class predictors for yeast applied to resequencing data have sufficient resolution to reveal a dyad pattern of integration in nucleosome-bound regions upstream of yeast tRNA genes for Ty1, Ty2, and Ty4, allowing us to extend knowledge about fine-scale target preferences revealed previously for experimentally-induced Ty1 insertions to spontaneous insertions for other copia-superfamily retrotransposons in yeast. Conclusion: McClintock (https://github.com/bergmanlab/mcclintock/) provides a user-friendly pipeline for the identification of TEs in short-read WGS data using multiple TE detectors, which should benefit researchers studying TE insertion variation in a wide range of different organisms. Application of the improved McClintock system to simulated and empirical yeast genome data reveals best-in-class methods and novel biological insights for one of the most widely-studied model eukaryotes and provides a paradigm for evaluating and selecting non-reference TE detectors in other species. [ABSTRACT FROM AUTHOR]

We report on the development of scintillating bolometers based on lithium molybdate crystals that contain molybdenum that has depleted into the double- β active isotope 100 Mo (Li 2 100 depl MoO 4 ). We used two Li 2 100 depl MoO 4 cubic samples, each of which consisted of 45-millimeter sides and had a mass of 0.28 kg; these samples were produced following the purification and crystallization protocols developed for double- β search experiments with 100 Mo-enriched Li 2 MoO 4 crystals. Bolometric Ge detectors were utilized to register the scintillation photons that were emitted by the Li 2 100 depl MoO 4 crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc Underground Laboratory (Spain). We observed that the Li 2 100 depl MoO 4 scintillating bolometers were characterized by an excellent spectrometric performance (∼3–6 keV of FWHM at 0.24–2.6 MeV γ s), moderate scintillation signal (∼0.3–0.6 keV/MeV scintillation-to-heat energy ratio, depending on the light collection conditions), and high radiopurity ( 228 Th and 226 Ra activities are below a few µBq/kg), which is comparable with the best reported results of low-temperature detectors that are based on Li 2 MoO 4 using natural or 100 Mo-enriched molybdenum content. The prospects of Li 2 100 depl MoO 4 bolometers for use in rare-event search experiments are briefly discussed. [ABSTRACT FROM AUTHOR]

The article describes the combination of experimental measurements with mathematical–physics analyses in flow investigation in the chambers of the scintillator detector, which is a part of the environmental scanning electron microscope. The chambers are divided with apertures by small openings that keep the desirable pressure differences between three chambers: The specimen chamber, the differentially pumped intermediate chamber, and the scintillator chamber. There are conflicting demands on these apertures. On the one hand, the diameter of the apertures must be as big as possible so that they incur minimal losses of the passing secondary electrons. On the other hand, it is possible to magnify the apertures only to a certain extent so the rotary and turbomolecular vacuum pump can maintain the required operating pressures in separate chambers. The article describes the combination of experimental measurement using an absolute pressure sensor and mathematical physics analysis to map all the specifics of the emerging critical supersonic flow in apertures between the chambers. Based on the experiments and their tuned analyses, the most effective variant of combining the sizes of each aperture concerning different operating pressures in the detector is determined. The situation is made more difficult by the described fact that each aperture separates a different pressure gradient, so the gas flow through each aperture has its own characteristics with a different type of critical flow, and they influence each other, thereby influencing the final passage of secondary electrons detected by the scintillator and thus affecting the resulting displayed image. [ABSTRACT FROM AUTHOR]

In positron emission tomography (PET), parallax errors degrade spatial resolution. The depth of interaction (DOI) information provides the position in the depth of the scintillator interacting with the γ-rays, thus reducing parallax errors. A previous study developed a Peak-to-Charge discrimination (PQD), which can separate spontaneous alpha decay in LaBr3:Ce. Since decay constant of GSO:Ce depends on Ce concentration, the PQD is expected to discriminate GSO:Ce scintillators with different Ce concentration. In this study, the PQD-based DOI detector system was developed, which can be processed online and implemented in PET. A detector was composed of four layers of GSO:Ce crystals and a PS-PMT. The four crystals were obtained from both the top and bottom of ingots with a nominal Ce concentration of 0.5 mol% and 1.5 mol%. The PQD was implemented on the Xilinx Zynq-7000 SoC board with 8ch Flash ADC to gain real-time processing, flexibility, and expandability. The results showed that the mean Figure of Merits in 1D between four scintillators are 1.5, 0.99, 0.91 for layers between 1st–2nd, 2nd–3rd, and 3rd–4th respectively, and the mean Error Rate in 1D between four scintillators are 3.50%, 2.96%, 13.3%, and 1.88% for layers 1, 2, 3, and 4, respectively. In addition, the introduction of the 2D PQDs resulted in the mean Figure of Merits in 2D greater than 0.9 and the mean Error Rate in 2D less than 3% in all layers. [ABSTRACT FROM AUTHOR]

Energy nonlinearity and resolution in liquid scintillator (LS) detectors are correlated and particle-dependent. A unified energy response model for liquid scintillator detectors has been presented in details. This model has advanced a data-driven approach to calibrate the particle-dependent energy response, using both the monoenergetic γ -ray sources and the continuous β spectra of 12 B and Michel e - induced by cosmic muons. Monte Carlo studies have demonstrated the effectiveness and robustness of the proposed model, in particular, the positron energy resolution can be extracted in the absence of positron sources. This work will provide a feasible approach of simultaneous calibration of energy nonlinearity and resolution for the running and future LS detectors. [ABSTRACT FROM AUTHOR]

Terahertz (THz) technology has great potential for applications in various fields, such as security imaging detection, optical communication, environmental quality monitoring, and life sciences. Most of these applications require THz detectors with high sensitivity, fast response, and a miniaturized size that can operate at room temperature. In this study, we present a graphene THz detector integrated with an asymmetric bowtie antenna. The asymmetric antenna confines the incident THz waves into the graphene active layer, leading to photocurrent generation and its directional flow. The maximum responsivity of this device can reach 19.6 V/W at 2.52 THz, with a noise–equivalent power (NEP) of 0.59 nW /Hz0.5. Additionally, the response time is less than 21 μs, with an active area of less than 1500 μm2. Such a small device enables THz imaging with a spatial resolution as small as 200 μm. These results provide a feasible way to design miniaturized and integrable two–dimensional material–based THz detectors. [ABSTRACT FROM AUTHOR]

A two-dimensional beam monitoring detector named π 2 has been developed and tested at the Bern University Hospital, using an 18 MeV proton beam provided by a medical cyclotron. This non-destructive device utilises a scintillating compound (P47 phosphor) coated onto a thin aluminium foil that is angled at 45 ∘ with respect to the beam axis. The scintillating light produced when the beam passes through the foil is captured by a CMOS camera, resulting in a two-dimensional image of the beam profile. Custom software is then used to analyse the image and extract valuable information about the beam's position, shape, and intensity. The focus of the experimental work was on characterising the performance of the π 2 with the 18 MeV proton beam. The linearity of the detector's output signal was evaluated for proton fluxes ranging from 2 · 10 10 cm − 2 · s − 1 to 5 · 10 11 cm − 2 · s − 1 . Furthermore, the beam profiles measured with the π 2 were found to be consistent with reference measurements obtained using alternative beam monitors. Additionally, the experiments also involved studying the beam scattering caused by the foil and scintillating layer. Finally, in a long-term radiation test, the detector demonstrated a stable response up to an integrated proton flux of 3 · 10 15 cm − 2 . The π 2 is currently being used at the Bern cyclotron for monitoring beams in the development of new methods for medical radioisotope production and for radiation hardness studies. The π 2 has potential applications in several fields that involve the use of accelerated ions, such as cancer particle therapy, medical radioisotope production and radiation hardness studies. [ABSTRACT FROM AUTHOR]

The paper considers and compares methods for obtaining spectra of fast neutrons using detectors based on a diamond sensor, an organic (plastic) scintillator for separating neutrons and γ-quants, and a spectrometric set of threshold activation detectors. The neutron spectrum was unfolded using the methods of least squares, Tikhonov regularization, neural networks, and maximum entropy, implemented in the MAXED code, as well as the GRAVEL iterative algorithm. In order to form detector response matrices, mathematical simulation methods and analytical calculations were used followed by verification using experimental data. The unfolding quality criteria, according to which the best method is selected, are given. [ABSTRACT FROM AUTHOR]

Boron neutron capture therapy (BNCT) is one of the radiation therapies using neutrons. In BNCT, neutron monitoring is essential to ensure safety and evaluate the effect of treatments. As a neutron monitor for BNCT, we are developing an optical-fiber-based neutron detector using a small Li glass scintillator. This type of detector shows a clear neutron peak in the pulse height spectrum and has a high counting-rate capability owing to its short decay time. However, the sensitivity of the detector is uncontrollable owing to its random scintillator shape. In this study, we propose a Li glass transparent composite scintillator, in which Li glass grains and UV-curable resin are mixed, to realize a small and shape-controlled scintillator. We first fabricated the Li glass transparent composite scintillator and then experimentally confirmed that its response showed a clear neutron peak. We also fabricated an optical-fiber-based neutron detector using the Li glass transparent composite scintillator. The scintillator was formed into a hemispherical shape at the tip of an optical fiber. We confirmed the response of the optical-fiberbased detector, which showed a clear neutron peak. The experimentally evaluated sensitivity of the fabricated optical-fiber-based detector roughly agreed with the sensitivity estimated from its shape and size. Therefore, we conclude that the sensitivity of the optical-fiber-based neutron detector can be roughly controlled by using the Li glass transparent composite scintillator. [ABSTRACT FROM AUTHOR]

Developing a ceramic scintillator operating in a phoswich detector is a feasible way for pulse shape discrimination. A YAG:Ce transparent ceramic scintillator has been synthesized by using the vacuum sintering method. In this work, we present a new phoswich detector mainly developed for the determination of low radioactivity levels. The system was constructed by combining a transparent ceramic scintillator, for the detection of α particles, and a CsI:Tl crystal, for the detection of γ-rays. With the device proposed here, the particle identification in a mixed α–γ field has been achieved with the rise time discrimination method. Furthermore, the figure of merit can also be improved using the phoswich detector. The higher reliability, simplicity, and low cost of the design that combines ceramics and crystals make the YAG ceramic have extremely good application prospects. [ABSTRACT FROM AUTHOR]

The anti-Compton phoswich (ACP) detector, which is composed of multiple scintillators with one photomultiplier tube, takes into account the Compton suppression function and portability, and therefore, a discussion on how to design its shape to improve the performance of the detector has become necessary. Based on an ACP detector using a well-typed LaBr3:Ce/NaI:Tl composite scintillator that has been developed in the laboratory in early work, this study uses GEANT4 to simulate and study the influence of the change in the shape and size of the secondary scintillator on the performance of the detector, such as the Compton suppression ratio, the energy resolution, and the full-energy peak (FEP) loss. In the course of the study, we mainly investigate the variation of the performance of the detector in two ways. First, the inclination angle of the truncated cone is gradually changed to compare its FEP address and Compton suppression ratio. Second, the case of the well-shaped and annular-shaped secondary scintillators is compared, respectively, to find out their impact on energy resolution and FEP address. The final results show that, compared with the ACP detector using a φ75 × 90 mm2 LaBr3:Ce/NaI:Tl cylindrical composite scintillator, a truncated cone-shaped composite scintillator of 0.8 inclination may have an equivalent 137% light yield (137% signal-to-noise ratio), a Compton suppression ratio of 89.62% (at 662 keV), 89.98% FWHM energy resolution, and a volume reduction of 36.74%, which means that the weight of the detector is reduced by 2.107 kg. [ABSTRACT FROM AUTHOR]

We present here a characterization of the low background NaI(Tl) crystal NaI-33 based on a period of almost one year of data taking (891 kg × days exposure) in a detector configuration with no use of organic scintillator veto. This remarkably radio-pure crystal already showed a low background in the SABRE Proof-of-Principle (PoP) detector, in the low energy region of interest (1–6 keV) for the search of dark matter interaction via the annual modulation signature. As the vetoable background components, such as 40 K, are here sub-dominant, we reassembled the PoP setup with a fully passive shielding. We upgraded the selection of events based on a Boosted Decision Tree algorithm that rejects most of the PMT-induced noise while retaining scintillation signals with > 90% efficiency in 1–6 keV. We find an average background of 1.39 ± 0.02 counts/day/kg/keV in the region of interest and a spectrum consistent with data previously acquired in the PoP setup, where the external veto background suppression was in place. Our background model indicates that the dominant background component is due to decays of 210 Pb, only partly residing in the crystal itself. The other location of 210 Pb is the reflector foil that wraps the crystal. We now proceed to design the experimental setup for the physics phase of the SABRE North detector, based on an array of similar crystals, using a low radioactivity PTFE reflector and further improving the passive shielding strategy, in compliance with the new safety and environmental requirements of Laboratori Nazionali del Gran Sasso. [ABSTRACT FROM AUTHOR]

Muon tomography (MT), based on atmospheric cosmic rays, is a promising technique suitable for nondestructive imaging of the internal structures of mountains. This method uses the measured flux distribution after attenuation, combined with the known muon angular and energy distributions and a 3D satellite map, to perform tomographic imaging of the density distribution inside a probed volume. A muon tomography station (MTS) requires direction-sensitive detectors with a high resolution for optimal tracking of incident cosmic-ray muons. The spherical liquid scintillator detector is one of the best candidates for this application due to its uniform detection efficiency for the whole 4 π solid angle and its excellent ability to distinguish muon signals from the radioactive background via the difference in the energy deposit. This type of detector, with a 1.3 m diameter, was used in the Jinping Neutrino Experiment (JNE). Its angular resolution is 4.9 degrees. Following the application of imaging for structures of Jinping Mountain with JNE published results based on the detector, we apply it to geological prospecting. For mountains below 1 km in height and 2.8 g / cm 3 in the reference rock, we demonstrate that this kind of detector can image internal regions with densities of ≤2.1 g / cm 3 or ≥3.5 g / cm 3 and hundreds of meters in size. [ABSTRACT FROM AUTHOR]

Perovskite materials have attracted extensive attention because of their superior performance in the fields of photoelectric detection, photovoltaics, light-emitting diodes, metal–air batteries, etc. However, their development and application in the field of X-ray detectors have not been reviewed. In this paper, research on perovskite-based X-ray detectors is analyzed using the bibliometric method. This analysis sample includes the literature from 1997 to the present. In addition, the research status of perovskite-based scintillators and direct X-ray detectors under different crystallization conditions and different preparation methods is discussed. Finally, several problems that need to be overcome in the future of perovskite-based X-ray detectors are put forward. [ABSTRACT FROM AUTHOR]

A new scintillator based fast-ion loss detector (FILD) system has been designed for the Wendelstein 7-X (W7-X) stellarator. The mechanical design of the system is presented here along with engineering analyses of the system. This includes an assessment of the structural loads which also considers electromagnetic forces calculated for possible disruption scenarios as well as a mode frequency analysis of the system. Furthermore, an analysis of the thermal characteristics of the actively cooled probe head under prescribed steady state and transient heat loads is presented. Finally, the optical relay system is described and its properties used to forward model synthetic camera signals using the FILDSIM code and based on theoretical fast-ion losses incident on the probe head calculated using the ASCOT5 code. [ABSTRACT FROM AUTHOR]

(1) Background: The Exradin W2 is a commercially available scintillator detector designed for reference and relative dosimetry in small fields. In this work, we investigated the performance of the W2 scintillator in a 10 MV flattening-filter-free photon beam and compared it to the performance of ion chambers designed for small field measurements. (2) Methods: We measured beam profiles and percent depth dose curves with each detector and investigated the linearity of each system based on dose per pulse (DPP) and pulse repetition frequency. (3) Results: We found excellent agreement between the W2 scintillator and the ion chambers for beam profiles and percent depth dose curves. Our results also showed that the two-voltage method of calculating the ion recombination correction factor was sufficient to correct for the ion recombination effect of ion chambers, even at the highest DPP. (4) Conclusions: These findings show that the W2 scintillator shows excellent agreement with ion chambers in high DPP conditions. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the Exradin W2 scintillator, PTW microDiamond, IBA Razor Nano, and IBA Razor chamber detectors for small‑field dose measurements and validate the measured data against the EGSnrc user code and observe the variation between daisy‑chained and direct measurement methods for the above detectors. Materials and Methods: The W2 scintillator, microDiamond, Razor Nano, and Razor chamber detectors were used to measure the in‑plane and cross‑plane profiles and the output factors (OFs) at 10 cm depth, and 90 source‑to‑surface distance for 6MV X‑rays (Elekta Versa HD). The field sizes ranged from 0.5 cm × 0.5 cm to 5 cm × 5 cm. The BEAMnrc/ DOSXYZnrc user codes (EGSnrc) were used to simulate the reference profiles. Gamma analysis was performed to compare the measured and simulated dose distributions. Results: The OFs measured with the W2 scintillator, microDiamond, Razor Nano chamber, Razor chamber, and the calculated Monte Carlo (MC) showed agreement to within 1% for the 3 cm × 3 cm field size. The uncertainty in the MC simulation was observed to be 0.4%. The percent difference in OFs measured using daisy‑chained and direct measurement methods was within 0.15%, 0.4%, 1.4%, and 2.4% for microDiamond, W2 scintillator, Nano, and Razor chamber detectors, respectively. Conclusion: The lateral beam profiles and OFs of W2 scintillator, microDiamond, Razor Nano, and Razor chambers exhibit good agreement with the MC simulation within the nominal field sizes. Our results demonstrate that we can achieve considerable time‑saving by directly measuring small‑field OFs without daisy‑chained methods using microDiamond and W2 scintillator. In terms of ease of use, sensitivity, reproducibility, and from a practical standpoint, we recommend microDiamond for small‑field dosimetry. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Feasibility study of a SiPM-fiber detector for non-invasive measurement of arterial input function for preclinical and clinical positron emission tomography" published in the journal EJNMMI Physics. The correction relates to the funding section of the original article, which has been updated. The correct funding sources are listed, including support from the Universidad Complutense de Madrid, the Ministerio de Ciencia e Innovación, and the European Union NextGenerationEU/PRTR. The original article has been updated to reflect these changes. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. [Extracted from the article]

This article presents a physics-informed deep learning method for the quantitative estimation of the spatial coordinates of gamma interactions within a monolithic scintillator, with a focus on Positron Emission Tomography (PET) imaging. A Density Neural Network approach is designed to estimate the 2-dimensional gamma photon interaction coordinates in a fast lead tungstate (PbWO 4) monolithic scintillator detector. We introduce a custom loss function to estimate the inherent uncertainties associated with the reconstruction process and to incorporate the physical constraints of the detector. This unique combination allows for more robust and reliable position estimations and the obtained results demonstrate the effectiveness of the proposed approach and highlights the significant benefits of the uncertainties estimation. We discuss its potential impact on improving PET imaging quality and show how the results can be used to improve the exploitation of the model, to bring benefits to the application and how to evaluate the validity of the given prediction and the associated uncertainties. Importantly, our proposed methodology extends beyond this specific use case, as it can be generalized to other applications beyond PET imaging. [ABSTRACT FROM AUTHOR]

The advent of gadolinium-loaded Super-Kamiokande (SK-Gd) and of the soon-to-start JUNO liquid scintillator detector marks a substantial improvement in global sensitivity for the Diffuse Supernova Neutrino Background (DSNB). The present article reviews the detector properties most relevant for the DSNB searches in both experiments and estimates the expected signal and background levels. Based on these inputs, we evaluate the sensitivity of both experiments individually and combined. Using a simplified statistical approach, we find that both SK-Gd and JUNO have the potential to reach >3 σ evidence of the DSNB signal within 10 years of measurement. Combination of their results is likely to enable a 5 σ discovery of the DSNB signal within the next decade. [ABSTRACT FROM AUTHOR]

AMS-100 is the next-generation high-energy cosmic-ray experiment in Space. It is designed as a magnetic spectrometer with a geometrical acceptance of 100 m2 · sr to be operated for ten years at the Sun–Earth Lagrange Point 2. Its Time-of-Flight (TOF) detector is a crucial sub-detector for the main trigger and the particle identification constructed from individual scintillation counters. A fast time measurement with a resolution of 20 ps for a single counter is required to cover wide energy ranges for particle identification. A prototype counter has been designed based on a fast plastic scintillator tile readout by two silicon photomultipliers (SiPMs). An amplifier board was built to merge 16 SiPM channels into four readout channels in a hybrid connection. The signals are read out by a fast waveform digitizer. The timing performance was studied with electrons from a 90Sr source. A time resolution of 40 ps for a single counter has been achieved. Various operational and environmental conditions have been studied. [ABSTRACT FROM AUTHOR]

Cs2LiYCl6: Ce3+ (CLYC) is a dual-mode gamma-neutron scintillator with a medium gamma-ray resolution and pulse-shape discrimination (PSD) capability. The PSD performance of CLYC is greatly weakened when coupled with silicon photomultipliers (SiPMs) because of SiPMs' low detection efficiency for the ultrafast Core-Valence-Luminescence (CVL) component under gamma excitation. In our previous work, the PSD Figure-of-Merit (FoM) value was optimized to 2.45 at the gamma-equivalent energy region of the thermal neutron by using the charge comparison method. However, this value was reduced to 1.37 at the lower gamma-equivalent energy region of more than 325 keV, and neutrons were difficult to distinguish from gamma rays. Hence, new algorithms should be studied to improve the PSD performance at low gamma-equivalent energy regions. Convolutional Neural Networks (CNNs) have excellent image recognition capabilities, and thus, neutron and gamma-ray waveforms can be discriminated by their characteristics through a known training set. In this study, neutron and gamma-ray waveforms were measured with a 137Cs source and moderated 252Cf source via an SiPM array-coupled CLYC detector and divided into two groups: training and PSD testing. The CNN training set comprised 137Cs characteristic gamma-ray waveforms and thermal neutron waveforms that were discriminated by the charge comparison method from the training group. A CNN with two convolution-pooling layers was designed to accomplish PSD with the test group. The PSD FoM value of the CNN method was calculated to be 37.20 at the gamma-equivalent energy region of more than 325 keV. This result was much higher than that of the charge comparison method, indicating that neutrons and gamma rays could be better distinguished with the CNN method, especially at low gamma-equivalent energy regions. [ABSTRACT FROM AUTHOR]

Purpose: Detector arrays and profile‐scans have widely replaced film‐measurements for quality assurance (QA) on linear accelerators. Film is still used for relative output factor (ROF) measurements, positioning, and dose‐profile verification for annual Leksell Gamma Knife (LGK) QA. This study shows that small‐field active detector measurements can be performed in the easily accessed clinical mode and that they are an effective replacement to time‐consuming and exacting film measurements. Methods: Beam profiles and positioning scans for 4‐mm, 8‐mm, and 16‐mm‐collimated fields were collected along the x‐, y‐, and z‐axes. The Exradin W2‐scintillator and the PTW microdiamond‐detector were placed in custom inserts centered in the Elekta solid‐water phantom for these scans. GafChromic EBT3‐film was irradiated with single uniformly collimated exposures as the clinical‐standard reference, using the same solid‐water phantom for profile tests and the Elekta film holder for radiation focal point (RFP)/patient‐positioning system (PPS) coincidence. All experimental data were compared to the tissue‐maximum‐ratio‐based (TMR10) dose calculation. Results: The detector‐measured beam profiles and film‐based profiles showed excellent agreement with TMR10‐predicted full‐width, half‐maximum (FWHM) values. Absolute differences between the measured FWHM and FWHM from the treatment‐planning system were on average 0.13 mm, 0.08 mm, and 0.04 mm for film, microdiamond, and scintillator, respectively. The coincidence between the RFP and the PPS was measured to be ≤0.5 mm with microdiamond, ≤0.41 mm with the W2‐1 × 1 scintillator, and ≤0.22 mm using the film‐technique. Conclusions: Small‐volume field detectors, used in conjunction with a clinically available phantom, an electrometer with data‐logging, and treatment plans created in clinical mode offer an efficient and viable alternative for film‐based profile tests. Position verification can be accurately performed when CBCT‐imaging is available to correct for residual detector‐position uncertainty. Scans are easily set up within the treatment‐planning‐system and, when coupled with an automated analysis, can provide accurate measurements within minutes. [ABSTRACT FROM AUTHOR]

Fano factor is a quantity used to measure the departure of the observed variance in the number of charge carriers produced from that predicted using poison statistics. Fano factor varies with the detector type. In case of proportional counters and semiconductor detectors, it is substantially less than unity, whereas, for scintillator detectors, it would be unity. Even in case of semiconductor detectors, it varies with the type and the shape of the detector. Another source of fluctuations that gives the overall resolution of the detector is preamplifier noise. Oversquare coaxial HPGe detectors are a recent development in the field. Literature on the Fano factor of oversquare large volume coaxial detector is not available. In this work, the Fano factor and the electronic noise of an oversquare HPGe coaxial detector are estimated after optimizing the shaping parameters. The Fano factor for the oversquare HPGe detector is estimated as 0.1291 keV, which agrees with the ideal value of 0.13 by 99.98%. The preamplifier noise was found to be 0.048 keV which is 35% lesser than the reported value. [ABSTRACT FROM AUTHOR]

In 1956 Reines & Cowan discovered the neutrino using a liquid scintillator detector. The neutrinos interacted with the scintillator, producing light that propagated across transparent volumes to surrounding photo-sensors. This approach has remained one of the most widespread and successful neutrino detection technologies used since. This article introduces a concept that breaks with the conventional paradigm of transparency by confining and collecting light near its creation point with an opaque scintillator and a dense array of optical fibres. This technique, called LiquidO, can provide high-resolution imaging to enable efficient identification of individual particles event-by-event. A natural affinity for adding dopants at high concentrations is provided by the use of an opaque medium. With these and other capabilities, the potential of our detector concept to unlock opportunities in neutrino physics is presented here, alongside the results of the first experimental validation. Liquid scintillator detectors have been used to study neutrinos ever since their discovery in 1956. The authors introduce an opaque scintillator detector concept for future neutrino experiments with increased capacity for particle identification and a natural affinity for doping. [ABSTRACT FROM AUTHOR]

X-ray radiography is the most widely used imaging technique with applications encompassing medical and industrial imaging, homeland security, and materials research. Although a significant amount of research and development has gone into improving the spatial resolution of the current state-of-the-art indirect X-ray detectors, it is still limited by the detector thickness and microcolumnar structure quality. This paper demonstrates high spatial resolution X-ray imaging with solution-processable two-dimensional hybrid perovskite single-crystal scintillators grown inside microcapillary channels as small as 20 µm. These highly scalable non-hygroscopic detectors demonstrate excellent spatial resolution similar to the direct X-ray detectors. X-ray imaging results of a camera constructed using this scintillator show Modulation Transfer Function values significantly better than the current state-of-the-art X-ray detectors. These structured detectors open up a new era of low-cost large-area ultrahigh spatial resolution high frame rate X-ray imaging with numerous applications. [ABSTRACT FROM AUTHOR]

The OSIRIS detector is a subsystem of the liquid scintillator filling chain of the JUNO reactor neutrino experiment. Its purpose is to validate the radiopurity of the scintillator to assure that all components of the JUNO scintillator system work to specifications and only neutrino-grade scintillator is filled into the JUNO Central Detector. The aspired sensitivity level of 10 - 16 g/g of 238 U and 232 Th requires a large ( ∼ 20 m 3 ) detection volume and ultralow background levels. The present paper reports on the design and major components of the OSIRIS detector, the detector simulation as well as the measuring strategies foreseen and the sensitivity levels to U/Th that can be reached in this setup. [ABSTRACT FROM AUTHOR]

Conventional single photon emission computed tomography (SPECT) relies on mechanical collimation whose resolution and sensitivity are interdependent, the best performance a SPECT system can attain is only a compromise of these two equally desired properties. To simultaneously achieve high resolution and sensitivity, we propose to use sensitive detectors constructed in a multi-layer inter spaced mosaicdetectors (MATRICES) architecture to accomplish part of the collimation needed. We name this new approach self-collimation. We evaluate three self-collimating SPECT systems and report their imaging performance: 1) A simulated human brain SPECT achieves 3.88% sensitivity, it clearly resolves 0.5-mm and 1.0-mm hot-rod patterns at noise-free and realistic count-levels, respectively; 2) a simulated mouse SPECT achieves 1.25% sensitivity, it clearly resolves 50- $\mu \text{m}$ and 100- $\mu \text{m}$ hot-rod patterns at noise-free and realistic count-levels, respectively; 3) a SPECT prototype achieves 0.14% sensitivity and clearly separates 0.3-mm-diameter point sources of which the center-to-center neighbor distance is also 0.3 mm. Simulated contrast phantom studies show excellent resolution and signal-to-noise performance. The unprecedented system performance demonstrated by these 3 SPECT scanners is a clear manifestation of the superiority of the self-collimating approach over conventional mechanical collimation. It represents a potential paradigm shift in SPECT technology development. [ABSTRACT FROM AUTHOR]