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Objective: Positron Emission Tomography (PET) is a well-known imaging technology for the diagnosis, treatment, and monitoring of several diseases. Most PET scanners use a Ring-Shaped Detector Configuration (RSDC), which helps obtain homogeneous image quality but are restricted to an invariable Field-of-View (FOV), scarce spatial resolution, and low sensitivity. Alternatively, few PET systems use Open Detector Configurations (ODC) to permit an accessible FOV adaptable to different target sizes, thus optimizing sensitivity. Yet, to compensate the lack of angular coverage in ODC-PET, developing a detector with high-timing performance is mandatory to enable Time-of-Flight (TOF) techniques during reconstruction. The main goal of this work is to provide a proof of concept PET scanner appropriate for constructing the new generation of ODC-PET suitable for biopsy guidance and clinical intervention during acquisition. The designed detector has to be compact and robust, and its requirements in terms of performance are spatial and time resolutions < 2 mm and < 200 ps, respectively. Methods: The present work includes a simulation study of an ODC-PET based on 2-panels with variable distance. The image quality (IQ) and Derenzo phantoms have been simulated and evaluated. The phantom simulations have also been performed using a ring-shaped PET for comparison purposes of the ODC approach with conventional systems. Then, an experimental evaluation of a prototype detector that has been designed following the simulation results is presented. This study focused on tuning the ASIC parameters and evaluating the scintillator surface treatment (ESR and TiO2), and configuration that yields the best Coincidence Time Resolution (CTR). Moreover, the scalability of the prototype to a module of 64 × 64mm2 and its preliminary evaluation regarding pixel identification are provided. Results: The simulation results reported sensitivity (%) values at the center of the FOV of 1.96, 1.63, and 1.18 for panel distances of 200, 250, and 300 mm, respectively. The IQ reconstructed image reported good uniformity (87%) and optimal CRC values, and the Derenzo phantom reconstruction suggests a system resolution of 1.6–2 mm. The experimental results demonstrate that using TiO2 coating yielded better detector performance than ESR. Acquired data was filtered by applying an energy window of ± 30% at the photopeak level. After filtering, best CTR of 230 ± 2 ps was achieved for an 8 × 8 LYSO pixel block with 2 × 2 × 12mm3 each. The detector performance remained constant after scaling-up the prototype to a module of 64 × 64mm2, and the flood map demonstrates the module's capabilities to distinguish the small pixels; thus, a spatial resolution < 2 mm (pixel size) is achieved. Conclusions: The simulated results of this biplanar scanner show high performance in terms of image quality and sensitivity. These results are comparable to state-of-the-art PET technology and, demonstrate that including TOF information minimizes the image artifacts due to the lack of angular projections. The experimental results concluded that using TiO2 coating provide the best performance. The results suggest that this scanner may be suitable for organ study, breast, prostate, or cardiac applications, with good uniformity and CRC. [ABSTRACT FROM AUTHOR]

High-energy radiation detection and imaging technology has significant applications in high-energy physics research, medical imaging, and industrial monitoring. Lead-free metal halides exhibit exceptional potential for conducting indirect detection of high-energy radiation due to their characteristics of low toxicity, strong stability, high light yield, and large Stokes shift. This paper reviews the most recent advances in lead-free metal halide scintillator materials for X-ray imaging. Subsequently, it lists the most important parameters of scintillator performance and introduces the production procedures for single crystal, powder, and nanocrystal scintillators. Furthermore, it discusses the manufacturing of scintillator films with improved performance, focusing on large-area flexible scintillator films and the coupling with microstructures. Finally, it discusses current challenges and opportunities for enhancing X-ray imaging using lead-free metal halide scintillator materials. [ABSTRACT FROM AUTHOR]

Background: The application of semi-conductor detectors such as cadmium–zinc–telluride (CZT) in nuclear medicine improves extrinsic energy resolution and count sensitivity due to the direct conversion of gamma photons into electric signals. A 3D-ring pixelated CZT system named StarGuide was recently developed and implemented by GE HealthCare for SPECT acquisition. The system consists of 12 detector columns with seven modules of 16 × 16 CZT pixelated crystals, each with an integrated parallel-hole tungsten collimator. The axial coverage is 27.5 cm. The detector thickness is 7.25 mm, which allows acquisitions in the energy range [40–279] keV. Since there is currently no performance characterization specific to 3D-ring CZT SPECT systems, the National Electrical Manufacturers Association (NEMA) NU 1-2018 clinical standard can be tailored to these cameras. The aim of this study was to evaluate the performance of the SPECT/CT StarGuide system according to the NEMA NU 1-2018 clinical standard specifically adapted to characterize the new 3D-ring CZT. Results: Due to the integrated collimator, the system geometry and the pixelated nature of the detector, some NEMA tests have been adapted to the features of the system. The extrinsic measured energy resolution was about 5–6% for the tested isotopes (99mTc, 123I and 57Co); the maximum count rate was 760 kcps and the observed count rate at 20% loss was 917 kcps. The system spatial resolution in air extrapolated at 10 cm with 99mTc was 7.2 mm, while the SPECT spatial resolutions with scatter were 4.2, 3.7 and 3.6 mm in a central, radial and tangential direction respectively. Single head sensitivity value for 99mTc was 97 cps/MBq; with 12 detector columns, the system volumetric sensitivity reached 520 kcps MBq−1 cc−1. Conclusions: The performance tests of the StarGuide can be performed according to the NEMA NU 1-2018 standard with some adaptations. The system has shown promising results, particularly in terms of energy resolution, spatial resolution and volumetric sensitivity, potentially leading to higher quality clinical images. [ABSTRACT FROM AUTHOR]

The ability to distinguish multiple forms of plutonium from one another, such as oxide and metal, is paramount in areas of nuclear nonproliferation and international safeguards. In its metal form, plutonium can be readily used in a nuclear weapon, while oxide forms are associated with nuclear reactor fuel. Oxide-based plutonium forms emit neutrons with an energy spectrum that is significantly different from the fission neutrons that are emitted from plutonium metal. Organic scintillation detectors output pulses that are proportional to the neutron energy deposited, and therefore present a means of distinguishing these plutonium forms based on their energy spectra. In this work, metal and oxide forms of plutonium were measured using a handheld detection system based on an organic glass scintillator. Monte Carlo modeling of these experiments was performed to provide insight into the origin of the features in the observed light output spectra. Through analysis of multiple regions of these spectra, in a matter of minutes we were able to unambiguously discriminate oxide and metal plutonium forms from one another and from a plutonium-beryllium neutron source, which was considered for comparison because these sources are commonly used in industrial applications. The ability to discriminate weapons-usable material from nuclear reactor fuel has applications in nuclear treaty verification and safeguards. [ABSTRACT FROM AUTHOR]

Rare earth ions with d-f transitions (Ce3+, Eu2+) have emerged as promising candidates for electroluminescence applications due to their abundant emission spectra, high light conversion efficiency, and excellent stability. However, directly injecting charge into 4f orbitals remains a significant challenge, resulting in unsatisfied external quantum efficiency and high operating voltage in rare earth light-emitting diodes. Herein, we propose a scheme to solve the difficulty by utilizing the energy transfer process. X-ray photoelectron spectroscopy and transient absorption spectra suggest that the Cs3CeI6 luminescence process is primarily driven by the energy transfer from the I2-based self-trapped exciton to the Ce-based Frenkel exciton. Furthermore, energy transfer efficiency is largely improved by enhancing the spectra overlap between the self-trapped exciton emission and the Ce-based Frenkel exciton excitation. When implemented as an active layer in light-emitting diodes, they show the maximum brightness and external quantum efficiency of 1073 cd m−2 and 7.9%, respectively. Rare-earth metal halide perovskites are promising for deep blue LEDs. Here, Yang et al. report energy transfer between self-trapped exciton and Frenkel exciton in Cs3CeI6 by adding excess CsI during thermal evaporation, resulting in deep blue LEDs with external quantum efficiency of 7.9% at 424 nm. [ABSTRACT FROM AUTHOR]

We report the photon (PL), electron (CL) and X-ray (XEL) induced luminescence characteristics of high aspect ratio ultra-long (~ 50 µm) ZnO nanorods (NRs) and discuss the potential for fast X-ray detection based on the consistent and efficient visible emission (~ 580 nm) from ZnO NRs. Nanostructured ZnO scintillators were rearranged to form a vertically well-aligned NR design in order to help light absorption and coupling resulting in luminescent and fast scintillation properties. The design of the nanorod array combines the key advantages of a low-cost growth technique together with environmentally friendly and widely available materials. A low temperature hydrothermal method was adopted to grow ZnO NRs in one cycle growth and their structural, optical and X-ray scintillation properties were investigated. The relatively short (~ 10 µm) ZnO NRs emitting in the near-band-edge region were found to be almost insensitive to X-rays. On the other hand, the higher XEL response of long ZnO NRs, which is a key parameter for evaluation of materials to be used as scintillators for high quality X-ray detection and imaging, along with a decay time response in the order of ns confirmed promising scintillation properties for fast and high-resolution X-ray detector applications. [ABSTRACT FROM AUTHOR]

This paper presents the effects of background reduction with anticoincidence logical condition between the sum of muon-sensitive large scintillator veto detectors and a germanium detector as well as the time evolution of rejected, muon-induced coincidence gamma spectra. A special attention is paid to neutron effects. The digital event-by-event registration used for data acquisition opens possibilities to study in an off-line mode the variety of effects related to the time structure of all signals registered by detectors. In our laboratory currently we use two such systems with in-house written software Veto for off-line data analysis. [ABSTRACT FROM AUTHOR]

We present the development of a dual-detector system designed for investigating the spectral shape of forbidden non-unique beta decays. Two PbMoO 4 scintillating crystals were carefully prepared for heat and light detection at milli-Kelvin (mK) temperatures. Notably, one crystal was synthesized using archaeological lead, while the other was composed of natural modern lead. The significance of employing two crystals lies in their identical dimensions and proximity, resulting in similar environmental background exposure. Their distinct internal radioactivities, particularly associated with 210 Pb, introduce a distinguishing factor between the spectra measured in the two detectors. Our detection method includes achieving clear particle identification through the relative amplitudes of light and heat signals for both crystals. This report compares the electron-induced spectra within energy regions both below and above the endpoint of 210 Bi beta decay. This comparative study provides valuable insights into an exact measurement of the 210 Bi decay spectrum, forbidden non-unique beta decay. [ABSTRACT FROM AUTHOR]

This study delves into investigating the influence of pH on the scintillation characteristics of YAG: Ce3+ nanoscintillators. Six sample detectors were fabricated using cerium-activated YAG powder synthesized via the sol–gel method at different pH levels. The aim is to identify the optimal pH for designing efficient radiation detectors, thus advancing radiation detection technologies. Results underscore pH's role in optimizing YAG: Ce3+ nanoscintillator performance. Synthesis at pH = 4 exhibited superior performance, with a scintillation light yield of 26384 ± 3500 ph/MeV and a fast component decay of 82 ns. These findings inform the synthesis and optimization of YAG: Ce3+ nanoscintillators, benefiting applications such as radiation detection and medical imaging. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of cerium-doped lanthanum fluoride (La(1−x)CexF3) nanocrystals have been carried out. The surfaces of La(1−x)CexF3 nanocrystals were modified with oleic acid using the co-precipitation technique, and then doped with cerium with various mole fractions (x) = 0.05, 0.10, 0.15, 0.20, and 0.25. The nanocrystals produced were characterized for their crystal structure using x-ray diffraction (XRD), their morphology by transmission electron microscopy (TEM), their functional group identification using Fourier-transform infrared (FTIR), and Raman spectroscopy, and their photoluminescence behavior using photoluminescence (PL) spectroscopy. Detailed investigations revealed that, based on the XRD data and TEM images, La(1−x)CexF3 exhibits trigonal-structured nanocrystals with the symmetry space group P-3c1. Among the samples, La0.75Ce0.25F3 exhibited the sharpest PL peak. The PL spectra for La0.75Ce0.25F3 nanocrystals excited at 370 nm and showed an intense emission peak at 495 nm with a lifetime τ = 1.523 × 10−10 s. This emission was assigned to the 5d → 4f (2F5/2 and 2F7/2) transitions of Ce3+ energy levels, indicating a luminescence center mechanism. These results indicate that the synthesized La0.75Ce0.25F3 is a promising phosphor material for detector scintillators. [ABSTRACT FROM AUTHOR]

The thickness of the scintillation films in indirect X−ray detectors can significantly influence their luminescence intensity. However, due to the scattering and attenuation of incoherent photons, thick scintillation films tend to reduce light yield. Herein, a highly transparent perovskite glass−ceramic scintillation film, in which the CsPbBr3 nanocrystals are in-situ grown inside a transparent amorphous polymer structure, is designed to achieve ultrastable and efficient X-ray imaging. The crystal coordination−topology growth and in−situ film formation strategy is proposed to control the crystal growth and film thickness, which can prevent light scattering and non−uniform distribution of CsPbBr3 nanocrystals while providing sufficient film thickness to absorb X−ray, thus enabling a high−quality glass−ceramic scintillator without agglomeration and Ostwald ripening. This glass−ceramic scintillation film with a thickness of 250 μm achieves a low detection limit of 326 nGyair s−1 and a high spatial resolution of 13.9 lp mm−1. More importantly, it displays remarkable scintillation stability under X−ray irradiation (radiation intensity can still reach 95% at 278 μGyair s−1 for 3600 s), water soaking (150 days), and high−temperature storage (150 days at 60 °C). Hence, this work presents a approach to construct ultrastable and flexible scintillation films for X−ray imaging with reduced light scattering and improved resolution. [ABSTRACT FROM AUTHOR]

Autonomous nuclear reactor monitoring is a key aspect of the International Atomic Energy Agency's strategy to ensure nonproliferation treaty compliance. From the rise of small modular reactor technology, decentralized nuclear reactor fleets may strain the capacities of such monitoring and requires new approaches. We demonstrate the superior capabilities of a gamma detection system to monitor the criticality of a zero power nuclear reactor from beyond typical vessel boundaries, offering a powerful alternative to neutron-based systems by providing direct information on fission chain propagation. Using the case example of the research reactor CROCUS, we demonstrate how two bismuth germanate scintillators placed outside the reactor vessel can precisely observe reactor criticality using so called noise methods and provide core status information in seconds. Our results indicate a wide range of applications due to the newly gained geometric flexibility that could find use in fields beyond nuclear safety. [ABSTRACT FROM AUTHOR]

The luminescence and scintillation characteristics of cerium-doped yttrium aluminum garnet crystals grown from melts in vacuum have been analyzed. Absorption and X-ray luminescence spectra, X-ray luminescence decay kinetics, and scintillation specific light yield in a wide range of activator concentrations (from 0.0036 to 1.175 at % with respect to substitution for yttrium at the c sites of the garnet structure) have been studied. Effective quenching of the intrinsic luminescence of antisite and vacancy defects of the base crystal in the UV region with an increase in the activator concentration has been found. The optimal activator concentration has been determined in order to increase the X-ray luminescence intensity and the scintillation light yield of Ce3+ ions, with allowance for the technological features of growth of single crystals of high optical quality with a high Ce3+ concentration by the horizontal directional crystallization in vacuum. The dependences of the X-ray luminescence kinetics on the activator concentration have been analyzed. It is shown that crystals with the specific light yield up to 25 000 ph/MeV can be grown. [ABSTRACT FROM AUTHOR]

The article describes a prototype device for monitoring the level of phase separation, which can be used for operational control of the delayed coking process in the petrochemical industry. A scheme and design of an experimental device developed by the authors, consisting of an organic plastic scintillator and an array of silicon photomultipliers, is presented. A computer simulation of the response of a scintillation detector under conditions of the actual geometry of the coke drum is presented. Experimental results demonstrating the performance of the device are presented. [ABSTRACT FROM AUTHOR]

The temperature effect plays an important role in the response function and efficiency of detectors. In this study, the behavior of doped NaI (Tl) and plastic scintillators was evaluated and compared with temperature changes, in a similar condition, for the first time. The detection system uses an experimental setup consisting of a 60Co source, NaI (Tl) detector, and a plastic scintillation detector. The results show that the recorded count rates from NaI (Tl) detector have a direct relation with temperature and lead to a 0.15%/°C error in the count rate. But in the same condition, the acquired count rates from the plastic scintillator detector were reduced with temperature increasing with a 0.57%/°C error in the count rate (inverse relation). Also, in this work, Linear and second-order polynomial regression were implemented on the recorded count rates from scintillators to compensate temperature effect. Finally, the acquired results were evaluated using the relative error (%) and diagram slope which expressed the superiority of the polynomial regression. Using this correction technique, the count rate changes reached to least and are stable with temperature fluctuations. The results of this research can be suitable for the industrial application of NaI (Tl) and plastic scintillators in level gauging, thickness gauging, and other nuclear gauging systems. [ABSTRACT FROM AUTHOR]

A diagnostic system has been developed on the gas dynamic trap (GDT) for detecting deuterium fusion products as well as X rays and γ rays produced by interactions of superheated electrons with structural elements of GDT and by capture of neutrons by nuclei of surrounding materials. The diagnostic system consists of the following three subsystems. The first subsystem is used to measure the longitudinal intensity profile of the dd-fusion reaction. It is based on diode detectors of 3.02-MeV protons and preamplifiers capable of operating with large-area diodes mounted in specially developed detector modules. The detectors are located inside the vacuum chamber of the GDT; they operate in the counting mode, which allows absolute measurements of the reaction-product flux with a time resolution of ~100 μs. Such detectors were created taking into account the operating experience of a proton detector based on an experimental diode in the GDT experiment. The second subsystem is composed of detectors developed earlier on the basis of SPM-5 plastic scintillator and a photomultiplier tube (PMT). These detectors are operated in the current mode and are intended to measure the neutron-generation intensity with a time resolution as high as 25 μs. These detectors are used jointly with the proton detectors in experiments with the additional heating to determine the contribution of γ rays and hard X rays. The third subsystem is a new neutron and γ-ray spectrometer based on a stilbene scintillator and a PMT, which was used for the first time in the experiment with deuterium plasma at the GDT facility. The detector is capable of separating particles of different types, in particular, under the operating conditions of the facility when superheated electrons are generated. [ABSTRACT FROM AUTHOR]

The characteristics of neutron scintillation detectors built on monolithic and heterogeneous scintillators containing 6Li were studied. The detectors were tested on a thermal neutron beam and on a stand with a source of γ-quanta 60Co. To process the signals received from the detector with a monolithic scintillator, three different γ-radiation discrimination algorithms were used: registration of pulses at a constant threshold and selection according to the pulse shape using two digital signal separation methods: charge integration and pulse duration measurement. For a homogeneous scintillator, pulse shape selection methods work approximately the same when separating thermal neutrons and γ-quanta and are significantly inferior to the method of registration at a constant threshold. In this case, the quality of the n/γ separation is worse than the result obtained with a heterogeneous scintillator when recording at a constant threshold. The purpose of the work is to compare the results of using digital methods for discrimination of gamma-quanta with the results obtained using heterogeneous scintillators. [ABSTRACT FROM AUTHOR]

For the first time, a bimetallic metal–organic framework of (MOF) La3+ and Ce3+ (Ce, La-MOF) was synthesized using a new solvothermal route. Also, monometallic MOFs La3+ (La-MOF) and Ce3+ (Ce-MOF) were synthesized using the mentioned method. To identify, and analyze the synthesized nanostructures, field emission scanning microscopy (FSEM), energy dispersive X-ray mapping (MAP), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal gravity curve (TGA), differential scanning calorimetry (DSC) analysis, Fourier transforms infrared (FT-IR) spectroscopy and Brunauer–Emmt–Teller surface area (BET) were used. According to the XRD diffraction patterns of Ce–La-MOF nanostructure, no additional peaks are derived from La species, which confirms that the addition of La does not change the crystalline phase structure of Ce-MOF. The size of La-MOF, Ce-MOF, and Ce, La-MOF nanostructures was calculated by the Williamson-Hall method and reported as 72.97, 55.46, and 81.55 nm, respectively. The specific surface area (BET) results for La-MOF, Ce-MOF, and Ce, La-MOF nanostructures were reported as 140, 200, and 260 m2 g−1 respectively, and the mean pore volumes of the nanostructures were reported as 0.019, 0.022 and 0.030 cm3 respectively. These values allow the use of these versatile nanostructures in various applications such as biosensing, separation and purification, medicine field, and catalysts. In addition, in this study, modified electrodes for synthesized nanostructures were tested for the electrooxidation of acetaminophen. And the obtained results show better electrocatalytic behavior of bimetallic Ce, La-MOF nanostructures than monometallic La-MOF, Ce-MOF nanostructures against acetaminophen. [ABSTRACT FROM AUTHOR]

First-principles calculations using Density Functional Theory (DFT) and the Wien2k package are used to analyze the structural, electrical, optical, and elastic characteristics of Li-based chloride perovskites LiXCl3 (X = Ca, Ba). The structural analysis demonstrates that these compounds are stable and have the space group pm-3m (no. 221). The calculations show that these materials possess an indirect band gap. For elastic properties, the Pugh's ratio (compound ductility), elastic constants, anisotropy factor, Poisson's ratio, and bulk modulus are analyzed. In 0–30 eV energy range, optical parameters such as dielectric function, extinction coefficient, reflectivity, absorption coefficient, refractive index, and optical conductivity, are measured. Optical properties, i.e. dielectric function, extinction coefficient, refractive index, absorption coefficient, reflectivity and optical conductivity, are evaluated in 0–30 eV energy range. The calculations show that these materials possess large band gap and are structurally anisotropic, making these better candidates for scintillator applications. [ABSTRACT FROM AUTHOR]

The basic structural, optical, elastic, and electronic properties are investigated in this research for QZnCl3 (Q = Li and Na) ternary centrosymmetric chloroperovskites compounds utilizing the DFT approach. The integrated TB-mBJ exchange–correlation potential within the WIEN2K computational simulation package serves for precise outcomes. The structural optimization is done by fitting the Birch-Murnaghan equation of state (EOS) for the primitive unit cell energy versus primitive unit cell volume. The parameters from the optimized fitted curves, Goldsmith's tolerance factor (tG), and octahedral coefficient predict the stable cubic structure of QZnCl3 (Q = Li and Na) centrosymmetric ternary chloroperovskites compounds. The elastic parameters which include cubic elastic constants (ECs), elastic moduli (E), Poisson's ratio (v), anisotropy factor (A), and the Pugh ratio (B/G) investigated through IRelast code display the mechanical stability, ductility, and toughness of interested centrosymmetric compounds. Predicted electronic band structures and densities of states (DOS) display that LiZnCl3 and NaZnCl3 possess an indirect (R-Γ) band gap of 3.82 eV and of 3.91 eV respectively, confirming that both the materials are wide band gap semiconductors. In optical properties, the spectral curves of several parameters are observed from 0 eV up to 15 eV incident photons energy, and it is revealed that the centrosymmetric chloroperovskites QZnCl3 (Q = Li and Na) are optically effective at high absorption coefficients (α(ω)), optical conductivity (σ(ω)), optical reflectivity (R(ω)), and energy loss (L(ω)) functions. The potential energy applications can be deemed for these materials, influencing electromagnetic radiation in the ultraviolet (UV) spectrum ranges. In a nutshell, the research on QZnCl3 (Q = Li and Na) demonstrate that these centrosymmetric materials are noteworthy and can be applied as energy storage systems, scintillators, and many other components of present electronic devices. [ABSTRACT FROM AUTHOR]

Fast neutron beams (E n > 1 MeV) are of relevance for many scientific and industrial applications. This paper explores fast neutron production using a TANDEM accelerator at the Legnaro National Laboratories, via an energetic ion beam (90 MeV 14 N ) onto a lithium target. The high energy models for nuclear collision of FLUKA foresee large neutron yields for reactions of this kind. The experiment aimed at validating the expected neutron yields from FLUKA simulations, using two separate and independent set-ups: one based on the multi-foil activation technique, and the other on the time of flight technique, by using liquid scintillator detectors. The results of the experiment show clear agreement of the measured spectra with the FLUKA simulations, both in the shape and the magnitude of the neutron flux at the measured positions. The neutron spectrum is centered around the 8 MeV range with mild tails, and a maximum neutron energy spanning up to 50 MeV. These advantageous results provide a starting point in the development of fast neutron beams based on high energy ion beams from medium-sized accelerator facilities. [ABSTRACT FROM AUTHOR]

Purpose: A solid-state PET/CT system uses bismuth germanium oxide (BGO) scintillating crystals coupled to silicon photomultipliers over an extended 32 cm axial field-of-view (FOV) to provide high spatial resolution and very high sensitivity. Performance characteristics were determined for this digital-BGO system, including NEMA and EARL standards. Methods: Spatial resolution, scatter fraction (SF), noise equivalent count rate (NECR), sensitivity, count rate accuracy, and image quality (IQ) were evaluated for the digital-BGO system as per NEMA NU 2-2018, at 2 sites of first clinical install. System energy resolution was measured. Bayesian penalized-likelihood reconstruction (BPL) was used for IQ. EARL Standards 2 studies were reconstructed by BPL combined with a contrast-enhancing deep learning algorithm. An Esser PET phantom was evaluated. Three patient examples were obtained with low-dose radiotracer activity: 2 MBq/kg of [18F]FDG ([18F]-2-fluoro-2-deoxy-d-glucose), 2.3 MBq/kg [68Ga]Ga-DOTA-TATE ([dodecane tetra-acetic acid,Tyr3]-octreotate), and 14.5 MBq/kg [82Rb]RbCl ([82Rb]-rubidium-chloride). Total scan times were ≤ 8 min. Results: NEMA sensitivity was 47.6 cps/kBq at the axial center. Spatial resolution at 1 cm from the center axis was ≤4.5 mm (filtered back projection) and ≤3.8 mm (ordered subset expectation maximization). SF was 35.6%, count rate accuracy was 2.16%, and peak NECR was 485.2 kcps at 16.9 kBq/mL. Contrast for IQ was 61.1 to 90.7% (smallest to largest sphere) with background variations from 7.6 to 2.1%, and a "lung" error of 4.7%. The average detector energy resolution was 9.67%. Image quality for patient scans was good. EARL Standards 2 criteria were robustly met and Esser phantom features ≥4.8 mm were resolved at 2 min per bed position. Conclusion: A solid-state 32 cm axial FOV digital-BGO PET/CT system provides good spatial and energy resolution, high count rates, and superior NEMA sensitivity in its class, enabling fast clinical acquisitions with low-dose radiotracer activity. [ABSTRACT FROM AUTHOR]

The average energy and multiplicity of prompt γ -rays from slow neutron-induced fission of 235 U have been measured using the STEFF spectrometer at the neutron time-of-flight facility n_TOF. The individual responses from 11 NaI scintillators were corrected for multiple γ -ray interactions, prompt fission neutrons and background counts before being deconvolved to estimate the emitted spectrum of prompt fission γ -rays. The results give an average γ -ray energy E ¯ γ of 1.71(5) MeV and multiplicity ν ¯ γ of 2.66(18) considering γ -rays emitted within the energy range 0.8–6.8 MeV. The n_TOF data has a slightly larger E ¯ γ and smaller ν ¯ γ than other recent measurements, however the product of the two is in agreement within quoted uncertainties. [ABSTRACT FROM AUTHOR]

The long-term stability of counters consisting of extruded-scintillator strips and wavelength-shifting fibers was studied. The aging study was carried out for scintillators and wavelength-shifting fibers before starting the mass production of counters. Aging at a higher rate and higher temperatures was used in the study, which was then continued as an interesting R&D work. The decrease in the light yield was at a level of 3% per year during an initial 5–6 years. The aging then proceeds slower and nearly ceases after a 26% decrease over 20 years. The study of preliminarily aged samples was repeated after a 2.5-year pause; it showed that the aging rate for these scintillators was less than 0.5% per year at 20°C. The results obtained over 4.5 years by direct measurements and by using a faster-aging technology were in good agreement. [ABSTRACT FROM AUTHOR]

The first results from the development of previously unknown tellurium-loaded plastic scintillators based on polystyrene, poly(methyl methacrylate), and their copolymers for detectors for the search and study of neutrinoless double beta decay are reported herein. A complex compound of diphenyltellurium oxide with di-(2-ethylhexyl)phosphoric acid and diphenyltellurium di-2-ethylhexanoate were used as tellurium-containing additives. The conditions for obtaining samples have been described and their light yield and transparency has been characterized. [ABSTRACT FROM AUTHOR]

Radiation detection plays an important role in diverse applications, including medical imaging, security, and display technologies. Scintillators, materials that emit light upon exposure to radiation, have garnered significant attention due to their exceptional sensitivity. Previous research explored polymer dots (P-dots) doped with iridium complexes as nano-sized scintillators for radiation detection, but these were constrained to emitting specific colors like red, green, and blue, limiting their utility. Recently, there has been a breakthrough in the development of white light emitters stimulated by UV–visible light. These emitters exhibit a broad spectral range in the visible wavelength, enhancing contrast and simplifying detection by visible-light sensors. Consequently, the quest for white color scintillators in radiation detection has emerged as a promising avenue for enhancing scintillation efficiency. In this study, we present a novel approach by applying P-dots doped with two iridium complexes to create white light-emitting nano-sized scintillators. These scintillators offer a wider spectral coverage within the visible-light wavelength range. Under UV light (365 nm) excitation, our synthesized P-dots exhibited remarkable white light emission. Moreover, when excited by electron beam irradiation, we observed the clear emission close to white emission which is valuable for improving the detection of radiation. [ABSTRACT FROM AUTHOR]

The B1133+16 pulsar was observed at a frequency of 111 MHz with the BSA radio telescope of the Pushchino Radio Astronomy Observatory from October 2022 to March 2023. Observations were conducted twice a week for two consecutive days. In total, 38 measurements of the scintillation parameters were carried out with a high frequency resolution (up to 65 Hz). We used continuous signal recording in the frequency band of 2.5 MHz. The signal was reconstructed using the coherent dedispersion method. The pulsar's dynamic spectra (DSP) were analyzed using the two-dimensional autocorrelation function (2DACF). The fine frequency structure of the pulsar's scintillation was investigated both through the analysis of time and frequency sections of 2DACF from DSP and through the spectra of individual pulses. The analysis of the frequency sections of the 2DACF showed that the true form of diffractive frequency distortions can be represented by a generalized exponential function with a characteristic frequency width of 1.2 kHz and an index of 0.57. Comparison of scintillation parameters separately for two components of the average profile showed that they are identical for both components. [ABSTRACT FROM AUTHOR]

The possibilities of engineering energy losses, created in the cascade process of electron-electron scattering during the interaction of multilayer dielectric structures with ionizing radiation, are considered. It is shown that the contribution of surface plasmons associated with layer boundaries to electron energy losses is significant only for nanometer layer thicknesses and increases with increasing electron energy. At the same time, surface states associated with longitudinal optical phonons in ionic crystals significantly change energy losses during electron thermalization and can lead to an increase in the efficiency and rise rate of scintillation in nanostructured systems. [ABSTRACT FROM AUTHOR]

As a part of radiation emergency response, a rapid method for estimation of gross-α and gross-β activities in urine samples using liquid scintillation counting technique was standardized and validated using spiked urine samples. Effect of various storage conditions such as temperature, storage time and use of preservatives on estimation of gross-α and gross-β activities was investigated systematically. Measurement results revealed that urine samples either should be stored at lower temperatures (≤ 5 °C) or should be acidified with 1% v/v HCl for quantification of gross-α and gross-β activities with bias ≤ 10%. [ABSTRACT FROM AUTHOR]

Rare-event search experiments located on-surface, such as short-baseline reactor neutrino experiments, are often limited by muon-induced background events. Highly efficient muon vetos are essential to reduce the detector background and to reach the sensitivity goals. We demonstrate the feasibility of deploying organic plastic scintillators at sub-Kelvin temperatures. For the NUCLEUS experiment, we developed a cryogenic muon veto equipped with wavelength shifting fibers and a silicon photo multiplier operating inside a dilution refrigerator. The achievable compactness of cryostat-internal integration is a key factor in keeping the muon rate to a minimum while maximizing coverage. The thermal and light output properties of a plastic scintillation detector were examined. We report first data on the thermal conductivity and heat capacity of the polystyrene-based scintillator UPS-923A over a wide range of temperatures extending below one Kelvin. The light output was measured down to 0.8 K and observed to increase by a factor of 1.61 ± 0.05 compared to 300 K. The development of an organic plastic scintillation muon veto operating in sub-Kelvin temperature environments opens new perspectives for rare-event searches with cryogenic detectors at sites lacking substantial overburden. [ABSTRACT FROM AUTHOR]

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There is a growing demand for materials for detecting ionizing radiation, which has led to the expansion of research and development of new scintillators. Typically, scintillators are synthesized by crystallizing materials at high temperatures, and their photoluminescence (PL) is difficult to tune in the visible spectral range. Therefore, composite materials based on CsPbBr3 perovskite nanocrystals (PNCs), which have a high average atomic number and a long charge-carrier diffusion length, are of particular interest and may be used for detecting ionizing radiation. Unlike bulk scintillators, PNCs are synthesized in solution at relatively low temperatures, with the PL tunable throughout the visible spectrum. The main problem limiting the widespread use of PNCs is their low stability upon contact with the environment. This study presents the results of experiments on the encapsulation of PNCs in a polystyrene matrix, the evaluation of the changes in the luminescence quantum yield (QY) over time, and the development of a technique for studying the amplitude characteristics of signals recorded during the interaction of α-particles with composite materials based on CsPbBr3 PNCs and polystyrene. The study has shown that composite samples based on PNCs and polystyrene retain a stable luminescence QY for two weeks. Using a 241Am source with a characteristic α-particle energy of about 4.6 MeV and γ-ray energy of 60 keV, the light output values were calculated for the samples studied. The maximum light output was 20% of that of the standard "fast" plastic scintillator (POPOP) at a volume fraction of PNCs in the composite of less than 1%, which indicates the prospect of PNCs as a basis for composite scintillators and their further use in X-ray diagnosis. [ABSTRACT FROM AUTHOR]

The analysis of amplitude spectra from a thin polystyrene-based scintillation counter on muon-enriched and hadron beams of channel 18 of the U-70 accelerator complex in Protvino has been presented. On the basis of statistics of 150 million events on the Hyperon-M setup, the contribution of the -fragmentation processes are highlighted and the cross sections of these processes on hadron and pion beams with a momentum of 7 GeV/c have been measured. In the future, the obtained result may be of interest for the method of analyzing the age of gas fields based on the concentration of helium in natural gas, the formation of which is possible in the reaction of fragmentation of carbon nuclei in interactions induced by high-energy cosmic muons. [ABSTRACT FROM AUTHOR]

Yttrium oxide doped with cerium ions (Ce4+:Y2O3) is a promising material for ceramic scintillators, while the use of nanosized particles can reduce optical losses in the obtained ceramics during its sintering. The method of solution combustion synthesis for the synthesis of nanoparticles, has the following advantages: organic compounds are usually used as fuel, which are easily oxidized and introduce minimal pollution into the product, and gaseous products are released during the combustion, which makes it possible to obtain ceramic substances in a finely dispersed state. Experiments were carried out to obtain nanopowders of yttrium oxide doped with cerium ions by combustion in solutions using glycine/(glycine and citric acid) as a reducing agent/fuel. Yttrium nitrates were the initial components for the preparation of aqueous solutions. The characteristics of the synthesized particles of yttrium oxide doped with cerium ions are presented. X-ray phase analysis of the obtained materials after annealing at t = 600°C have shown that all samples are powders with a single-phase structure. In accordance with the data of scanning electron microscopy and particle size distribution of aggregates, the distribution peak of Ce4+:Y2O3 particle aggregates is at 10–12 nm. It has been shown that the method of combustion in solutions can be successfully used for the synthesis of metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Alpha particle detection performances of a Hamamatsu R1828-01 model and a RCA 6342A model photomultiplier tubes (PMT) were tested. For the sensitivity of the PMTs to alpha particles, an Eljen AJ-440 model ZnS(Ag) scintillator material in sheet form was used in front of their windows. To test their performances, the alpha peaks of an 241Am source and the energy resolution values of the detectors that composed of these PMTs were compared. It has been showed that R1828-01 model PMT utilized for fast timing measurements in radiation detection could be used in alpha particle detection efficiently. This work revealed its another advantageous feature in addition to existing specifications. [ABSTRACT FROM AUTHOR]

POLAR-2, a plastic scintillator based Compton polarimeter, is currently under development and planned for a launch to the China Space Station in 2025. It is intended to shed a new light on our understanding of Gamma-Ray Bursts by performing high precision polarization measurements of their prompt emission. The instrument will be orbiting at an average altitude of 383 km with an inclination of 42° and will be subject to background radiation from cosmic rays and solar events. In this work, we tested the performance of plastic scintillation bars, EJ-200 and EJ-248M from Eljen Technology, under space-like conditions, that were chosen as possible candidates for POLAR-2. Both scintillator types were irradiated with 58 MeV protons at several doses from 1.89 Gy(corresponding to about 13 years in space for POLAR-2) up to 18.7 Gy, that goes far beyond the expected POLAR-2 life time. Their respective properties, expressed in terms of light yield, emission and absorption spectra, and activation analysis due to proton irradiation are discussed. Scintillators activation analyses showed a dominant contribution of β + decay with a typical for this process gamma-ray energy line of 511 keV. [ABSTRACT FROM AUTHOR]

Present work focuses to investigate the impact of rare earth ions (Ce and Gd) on the structural and magnetic properties of nanocrystalline nickel-zinc ferrite. The nanoparticles of Ni0.5Zn0.5Fe2O4, Ni0.5Zn0.5Ce0.02Fe1.98O4, and Ni0.5Zn0.5Gd0.02Fe1.98O4 were synthesized by citric acid–assisted sol–gel method. The formation of cubic spinel structure without additional impurity peaks was confirmed by X-ray diffraction (XRD) pattern. The crystallite size of Ni0.5Zn0.5Fe2O4 (R = 0) and Ni0.5Zn0.5R0.02Fe1.98O4 (R = Ce and Gd) nanoparticles was observed less than ~ 35 nm at sintering temperatures of ~ 300 to ~ 500 ℃. From magnetic measurements, the value of room temperature saturation magnetization of superparamagnetic Ni0.5Zn0.5Fe2O4 (R = 0) was found to be reduced with the doping of Ce and Gd ions from 44.19 ± 0.02 to 39.33 ± 0.03 emu/g and 35.18 ± 0.02 emu/g, respectively, at 300 ℃ and from 60.69 ± 0.04 to 54.11 ± 0.03 emu/g and 55.72 ± 0.04 emu/g, respectively, at 500 ℃. The detailed study of superparamagnetic relaxation in pure and rare earth-doped samples was performed by the thermal magnetization measurements under zero field cool (ZFC) and field cool (FC) processes. Mossbauer spectra revealed the absence of the quadrupole splitting for Ni0.5Zn0.5Ce0.02Fe1.98O4 at tetrahedral (A-site) and octahedral (B-site) sites which indicated cubic symmetry in the crystal structure. Although, the presence of negative asymmetry was observed in Ni0.5Zn0.5Gd0.02Fe1.98O4-doped ferrite sample. Magnetic materials with superparamagnetic properties are desirable in various biomedical applications. [ABSTRACT FROM AUTHOR]

Plastic scintillation microsphere (PSm) is a micron-sized plastic scintillator, and it is an organic scintillation material with good application prospects in the field of radioactivity analysis. However, the lack of simple industrial synthesis methods could limit bulk production of PSm with a reasonable cost. In this study, PSm materials were prepared via suspension polymerization and the repeatability of both the synthesis conditions and the radioactivity measurement performance were evaluated. Results indicated that PSm with a particle size distribution ranged around 90–200 μm can be reproducibly synthesized under certain conditions. Consistent counting efficiency for the 14C measurement in liquid samples using PSm has been obtained as long as sufficient PSm was added into the scintillation vial to completely cover the liquid volume. By comparing the spectral widths of samples with different concentrations of fluors, optimal PPO concentration of 1.5% and bis-MSB concentration of 0.015% was chosen to obtain a good light yield and a counting efficiency of up to 43.3% for 14C in water. Furthermore, it was observed that the 14C counting efficiency of PSm would be significantly affected by the quenching of the solution. [ABSTRACT FROM AUTHOR]

Strontium-90 emits beta-particles and decays into yttrium-90. At this time, the beta-particles released affect a human body, and liquid scintillation counting is used to detect such beta-particles. In general, cocktail method that mixes samples and liquid scintillators is used in conventional liquid scintillator counters. In the cocktail method, the degree of miscibility or solubility between samples and scintillators, precipitation phenomena, etc. reduce the reproducibility of the experiment. A new method for measuring beta-particles after separating samples and scintillators from each other is presented. In addition, several experiments are conducted to investigate the efficiency and tendency of the new method. [ABSTRACT FROM AUTHOR]

To minimize the environmental burden of the disposal of spent nuclear fuel, nuclide management process is one of good candidates to separate and collect major nuclides in the spent nuclear fuel. After high heat load nuclides, high mobile nuclides, and long-lived nuclides are separated, collected, and fabricated as the waste form for the disposal. From safeguards perspective, nuclear material of the TRU/RE waste form should be verified. The amount of Plutonium can be estimated by Cm/Pu ratio using burnup code calculations and Cm-244 measurement. In this study, a fast neutron coincidence counter for Cm-244 neutron measurement of the TRU/RE waste form was designed with EJ-276 plastic scintillation detectors using PTRAC of MCNP6.2. The preliminary experimental performance evaluation using one EJ-276 plastic scintillation detector was conducted. And total and coincidence counting efficiency using a Cf-252 neutron source was calculated with respect to the number of detectors. [ABSTRACT FROM AUTHOR]

The work describes features of the procedure for obtaining a response matrix to neutron radiation with energies from 1 to 19 MeV for a single-crystal stilbene scintillation detector. This response matrix is subsequently used in solving the problem of unfolding the neutron energy distribution at the detector location. The procedure for obtaining the matrix includes both experimental work and simulations of nuclear physics processes. In order to carry out the simulations, the Geant4 library package with the connected optical physics accounting module was used. The resulting matrix can be used as part of the amplitude method for unfolding the spectra of neutrons with energies in the range of 1–19 MeV with a step of 0.1 MeV. The obtained response matrix takes into account the main physical processes and instrumental effects of detectors based on organic scintillators, including the dependence of the light yield in the scintillator on the type and energy of charged particles, as well as the energy resolution of the detector depending on the energy of detected particles. In comparison with earlier results obtained using response matrices that do not take into account the above formation features of hardware spectra, it was possible to reduce the lower limit of the detected neutron energy from 1.5 to 1.0 MeV, as well as to increase the reliability of unfolded neutron energy distributions at the measurement point. The error in determining the neutron energy in the range of 1–15 MeV was not more than 200 keV. [ABSTRACT FROM AUTHOR]

We present the status of research and development of a new highly efficient liquid scintillator based on linear alkylbenzene and organosilicon scintillation fluor, so called NOL (Nanostructured Organosilicon Luminophore). The measurements of the emission kinetics under irradiation by gamma-quanta and alpha-particles were performed. The results of long term stability measurements are decribed. [ABSTRACT FROM AUTHOR]

Ageing of the plastic scintillators plays a significant role in the degradation of detectors' performance. Several effects are considered responsible for this process such as mechanical stresses, water penetration and oxidation due to exposure to ultraviolet radiation. The DANSS detector core consists of 2500 polystyrene based scintillation plates with wavelength shifting fiber readout (strips). The detector is located just below an industrial nuclear reactor of Kalininskaya NPP. The room housing the detector is air conditioned and has very low humidity. The temperature of about 20 C was maintained at the detector core. The performance of the strips is permanently monitored with atmospheric muons passing through the detector. Six years of measurements since April 2016 till March 2022 are reported. We observe the average light yield degradation of the strips at the level /year. The decrease of the wavelength shifting fiber attenuation length is /year. [ABSTRACT FROM AUTHOR]

Metal-loaded liquid organic scintillators (MeLS) are discussed from the point of view of light yield at high metal loading (Gd, Nd, Zr, In). It is shown that, when metal -diketonates are introduced into the scintillator, its light yield is always lower than when carboxylates are used, which is explained by the structural difference between these complexes. The nature of the metal in some cases (Nd) also affects the light attenuation length and, consequently, the MeLS light yield. The composition of the solvent (the fraction of aromatics in the main solvent) and the degree of purification of the introduced metal complex also have a significant effect on the light yield. [ABSTRACT FROM AUTHOR]

Laboratory observations of enhancements of energetic-electron population are presented during magnetic reconnection associated with strong tearing mode in non-disruptive tokamak plasmas. The hard X‑ray (HXR) spectrum detected by cadmium-telluride (CdTe) scintillator detectors and the non-thermal radiation measured by the electron cyclotron emission (ECE) are used to analyze the behaviors of energetic electrons on HL-2A. A population of energetic electrons is generated by parallel electric fields during magnetic reconnection, which is evidenced by the production of hard X-rays with energy 10 keV < Eγ < 200 keV. The results could assist to better understand the acceleration mechanism of electrons in the parameter-regime of tokamak plasma. It is observed that the energetic-electrons jointly accelerated by Ohmic electric fields and parallel electric fields have significant effects on the behaviors of low frequency MHD modes, namely, which excite Alfvénic and acoustic type instabilities during strong tearing modes (TMs). [ABSTRACT FROM AUTHOR]

Next-generation large-scale neutrino detectors, from Eos, at the 1 t scale, to Theia, at the 10 s-of-kt scale, will utilize differences in both the scintillation and Cherenkov light emission for different particle species to perform background rejection. This manuscript presents measurements of the scintillation light yield and emission time profile of water-based liquid scintillator samples in response to α radiation. These measurements are used as input to simulation models used to make predictions for future detectors. In particular, we present the timing-based particle identification achievable in generic water-based scintillator detectors at the 4 t, 1 kt, and 100 kt scales. We find that α / β discrimination improves with increasing scintillation concentration and we identify better than 80% α rejection for 90% β acceptance in 10% water-based liquid scintillator, at the 4 t scale. [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]

Purpose: Long axial field-of-view (LAFOV) systems have a much higher sensitivity than standard axial field-of-view (SAFOV) PET systems for imaging the torso or full body, which allows faster and/or lower dose imaging. Despite its very high sensitivity, current total-body PET (TB-PET) throughput is limited by patient handling (positioning on the bed) and often a shortage of available personnel. This factor, combined with high system costs, makes it hard to justify the implementation of these systems for many academic and nearly all routine nuclear medicine departments. We, therefore, propose a novel, cost-effective, dual flat panel TB-PET system for patients in upright standing positions to avoid the time-consuming positioning on a PET-CT table; the walk-through (WT) TB-PET. We describe a patient-centered, flat panel PET design that offers very efficient patient throughput and uses monolithic detectors (with BGO or LYSO) with depth-of-interaction (DOI) capabilities and high intrinsic spatial resolution. We compare system sensitivity, component costs, and patient throughput of the proposed WT-TB-PET to a SAFOV (= 26 cm) and a LAFOV (= 106 cm) LSO PET systems. Methods: Patient width, height (= top head to start of thighs) and depth (= distance from the bed to front of patient) were derived from 40 randomly selected PET-CT scans to define the design dimensions of the WT-TB-PET. We compare this new PET system to the commercially available Siemens Biograph Vision 600 (SAFOV) and Siemens Quadra (LAFOV) PET-CT in terms of component costs, system sensitivity, and patient throughput. System cost comparison was based on estimating the cost of the two main components in the PET system (Silicon Photomultipliers (SiPMs) and scintillators). Sensitivity values were determined using Gate Monte Carlo simulations. Patient throughput times (including CT and scout scan, patient positioning on bed and transfer) were recorded for 1 day on a Siemens Vision 600 PET. These timing values were then used to estimate the expected patient throughput (assuming an equal patient radiotracer injected activity to patients and considering differences in system sensitivity and time-of-flight information) for WT-TB-PET, SAFOV and LAFOV PET. Results: The WT-TB-PET is composed of two flat panels; each is 70 cm wide and 106 cm high, with a 50-cm gap between both panels. These design dimensions were justified by the patient sizes measured from the 40 random PET-CT scans. Each panel consists of 14 × 20 monolithic BGO detector blocks that are 50 × 50 × 16 mm in size and are coupled to a readout with 6 × 6 mm SiPMs arrays. For the WT-TB-PET, the detector surface is reduced by a factor of 1.9 and the scintillator volume by a factor of 2.2 compared to LAFOV PET systems, while demonstrating comparable sensitivity and much better uniform spatial resolution (< 2 mm in all directions over the FOV). The estimated component cost for the WT-TB-PET is 3.3 × lower than that of a 106 cm LAFOV system and only 20% higher than the PET component costs of a SAFOV. The estimated maximum number of patients scanned on a standard 8-h working day increases from 28 (for SAFOV) to 53–60 (for LAFOV in limited/full acceptance) to 87 (for the WT-TB-PET). By scanning faster (more patients), the amount of ordered activity per patient can be reduced drastically: the WT-TB-PET requires 66% less ordered activity per patient than a SAFOV. Conclusions: We propose a monolithic BGO or LYSO-based WT-TB-PET system with DOI measurements that departs from the classical patient positioning on a table and allows patients to stand upright between two flat panels. The WT-TB-PET system provides a solution to achieve a much lower cost TB-PET approaching the cost of a SAFOV system. High patient throughput is increased by fast patient positioning between two vertical flat panel detectors of high sensitivity. High spatial resolution (< 2 mm) uniform over the FOV is obtained by using capable monolithic scintillators. [ABSTRACT FROM AUTHOR]

The LHCb Upgrade phase II conditions require a significant change of the detector systems including the electromagnetic calorimeter (ECAL), which must be capable to sustain high radiation doses in the innermost region and provide good time resolution. The central part of the ECAL will be substituted by spaghetti calorimeter (SPACAL). This paper presents the results of the first cast lead–polystyrene SPACAL prototypes studies performed at the CERN SPS and DESY test beam areas. [ABSTRACT FROM AUTHOR]

The implementation of a density functional theory framework, specifically the full potential linearized augmented plane wave method, has been utilized to predict the electronic, structural, magnetic, and optical properties of Cs2LiCeBr6, a scintillating bromo-elpasolite material. The optimized lattice parameter "ao" is reported to be in reasonable accordance with the experimental value, and the lowest energy in the spin-polarized approach is observed. As per the Tran and Blaha modified Becke-Johnson potential approximation, the optimized results reveal that the band gap of the material is indirect at the momentum points from Γ-X. The calculated values for the band gap in the spin-up and down channels are 2.77 eV and 3.12 eV, respectively. The verification of ferromagnetic behavior is confirmed by the asymmetric densities of states in both spin schemes. Furthermore, based on the values of the band gap, the substance is classified as a ferromagnetic semiconductor. The optical properties are analyzed within the energy range spanning from 0 eV to 20 eV, and the Perdew-Burke-Ernzerhof generalized gradient approximation and the Tran and Blaha modified Becke-Johnson approximations are compared. The material being investigated demonstrates valuable characteristics, including absorption in the extreme ultraviolet range, reduced reflectivity, and elevated optical conductivity values. These properties make it suitable for various applications, including radiation detection in particle physics, medical instrument construction, security applications, and high-frequency devices that rely on ultraviolet radiation. [ABSTRACT FROM AUTHOR]