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Development of a solid-state position sensitive neutron detector prototype based on ?6Li-glass scintillator and digital SiPM arrays
摘要： Photomultiplier tubes (PMT) have been used extensively as the photodetector of choice in scintillation based detectors for cold and thermal neutrons. However, the limitations of PMT based scintillation neutron detectors such as their sensitivity to magnetic fields or their high operating voltages (> 1 kV) have triggered the search for alternative photodetectors for these applications. Silicon photomultipliers (SiPM) operate in the single photon regime, have lower operating voltages (~ 20 - 70 V) than PMTs and are insusceptible to magnetic field. Additional features of the SiPMs like their low production cost, compactness and higher readout rates make them a potential candidate to replace the photodetector part in these developments. Therefore, we are developing a scintillation neutron detector based on SiPM technology. The detector prototype with an active detection area of 13 cm × 13 cm is aimed to be used in the future at the TREFF instrument of the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany, for neutron reflectometry experiments. In this paper, we report the detector concept, its development and the simulation results for design optimization.
关键词： Geant4,Neutron scintillation detectors,Cold and thermal neutrons,Silicon Photomultipliers (SiPM)
更新于2025-09-23 15:23:52
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Study of energy and timing characteristics of 38.1mm?×?38.1mm CeBr3 scintillator detectors
摘要： We report the results of measurements and GEANT4 simulation for the performance of two 38.1mm × 38.1mm CeBr3 detectors. The linearity and energy resolution of both the detectors have been measured using low energy gamma sources in the range from 121.8 keV to 4.44 MeV. Maintaining the energy linearity condition, the best time resolution value of 423 ± 14 ps was measured for 1173–1332 keV photon pair from a 60Co source. A GEANT4 simulation was performed to reproduce the measured experimental spectrum and to estimate the absolute photopeak efficiencies at several energies up to 4.44 MeV.
关键词： Time resolution,GEANT4 simulation,Energy resolution,Scintillator,CeBr3
更新于2025-09-23 15:22:29
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G4Linac_MT, an easy-to-use Geant4-based code for modeling medical linear accelerator
摘要： In this paper, we present G4Linac_MT, a simple-to-use open source code developed to facilitate the use of the Geant4 C++ toolkit for the simulation of a medical linear accelerator (linac). This multithreaded code encapsulates several well-developed C++ modules serving to handle the complexity of coding geometry and material, to easy plot histograms of various physics quantities, to auto-merge output data created by all working threads into a single file, to well-estimate the number of simulated primary particles required to achieve data with a statistical uncertainty < 1% and also the CPU time required for, to use a set of variance reduction techniques as bremsstrahlung splitting, particle recycling, particle rotational splitting and stacking mechanism, to use a new format of phase space file based on HDF5-C++ scientific library which has been developed specially for this code. In order to minimize human effort required by Geant4 coding and validating of a linac, the code comes with a Java-based GUI application which contains separated GUI modules for linac head simulation, dose calculation, data analysis, geometry modeling and gamma index calculation. Results from Monte Carlo simulations of linac head of a Saturne 43 12 MV configuring a 10 × 10 cm2 radiation field are showed in order to demonstrate the G4Linac_MT capabilities. Thus, comparisons between simulated dosimetric functions and measured ones in a water phantom have been established by using a gamma index method and the results show a good agreement within 2.6%-1 mm accuracy. In addition, after optimizing variance reduction techniques, the overall CPU time spent by this multithreaded code has been decreased by a factor of 7.
关键词： Multi-threading,G4Linac_MT,Monte Carlo,Geant4,Linac
更新于2025-09-23 15:22:29
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SET Sensitivity of Tri-Gate Silicon Nanowire Field-Effect Transistors
摘要： The SET response of SOI tri-gate silicon nanowires is investigated using direct measurements of current transients. Resulting collected charge distributions are compared to simulations in two steps: Monte-Carlo simulations of deposited energy and TCAD simulation of collected charge, using detailed description of charge generation. Good agreement with experimental data is obtained. Current simulation tools can thus be used, with minor optimization, to simulate such integrated devices. The analysis of SETs show collected charge values lower than both the charge estimated from the LET and the charge actually generated in the nanowire, revealing a limited sensitivity of nanowire devices to high LET ions.
关键词： Nanowire,SEE,Single-Event Transient,Ultra-Thin SOI,Particle-matter interaction,Single-Event Effect,Geant4,FinFET,TCAD,Multiple-gate,Simulation,SET,Experiments
更新于2025-09-23 15:21:01
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - A 220 GHz GaN HEMT Power Amplifier
摘要： Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Problems observed in electron backscattering simulation in previous publications have been addressed by evolutions in the Geant4 geometry domain.
关键词： Electrons,Monte Carlo,simulation,Geant4
更新于2025-09-23 15:19:57
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Photonic-crystal Lasers with Extremely Short Embedded Active-regions
摘要： Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Problems observed in electron backscattering simulation in previous publications have been addressed by evolutions in the Geant4 geometry domain.
关键词： Electrons,Monte Carlo,simulation,Geant4
更新于2025-09-19 17:13:59
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Spectroscopy of High-Intensity Bremsstrahlung Using Compton Recoiled Electrons
摘要： Recoiled Compton electrons of 180 deg have been utilized to measure the energy distribution of high-intensity bremsstrahlung. An optimized detector-collimator configuration was used for detection and spectrum measurement of recoiled electrons. The spectrum has been reconstructed using Compton cross sections retrieved from the ENDF/B.VIII.0 library. The measured spectrum has been further validated using theoretical simulation by the Geant4 code with incorporating ENDF/B-VIII.0–recommended cross sections. The simulated spectrum matches the measured spectrum if the spatial spread and energy spread of the electron beam are accounted for in the simulations.
关键词： Bremsstrahlung spectroscopy,Compton scattering,Geant4,nuclear instrumentation
更新于2025-09-11 14:15:04
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[IEEE 2018 2nd International Conference on Biomedical Engineering (IBIOMED) - Bali, Indonesia (2018.7.24-2018.7.26)] 2018 2nd International Conference on Biomedical Engineering (IBIOMED) - Could Water Replace Muscle Tissue Used in Electron and Photon Beams?: A Monte Carlo Study
摘要： This study was conducted to evaluate the use of different phantom materials (muscle_ICRP, muscle_ICRU, and water) using Geant4-GAMOS Monte Carlo method. GAMOS which based on the Geant4 toolkit developed by European Organization for Nuclear Research (CERN) is a Monte Carlo simulation software. The material composition and density of muscle skeletal (ICRP), muscle striated (ICRU), and water (ICRU) used in this simulation were provided by Geant4 cross section data. Simulation objects consist of world, detector, source, and phantom. The phantom material used was distinguished. The source was placed inside a tube while detector was placed inside phantom. The detector was separated 2 cm from source in +x direction. The photon and electron beam with varied energies 0.5, 1.0, 1.5, and 2.0 MeV was used as source. The simulation time for each simulation was different depend on the incident particle type, particle energy, and phantom material composition. Electron beam takes longer time simulation than photon beam for varied phantom materials. The Rayleigh scattering, Compton scattering, and the photo-electric effect were occurred in each simulation but gamma conversion into electron and positron pairs only discovered in 1.5 and 2.0 MeV photon beam. The positron was produced because of pair production interaction. The energy histogram collected in this simulation shows that the muscle (ICRP and ICRU) material can be replaced by water if the muscle depth from the skin surface is not more than 2 cm. This results also were confirmed by comparing the mass coefficient attenuation and stopping power ratio curves between muscle (ICRP and ICRU) and water material extracted using other Monte Carlo software, EGSnrc.
关键词： stopping power,Monte Carlo,mass attenuation coefficient,Geant4,GAMOS,muscle
更新于2025-09-10 09:29:36
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Simulation of the ELIGANT-GN array performances at ELI-NP for gamma beam energies larger than neutron threshold
摘要： Performance of the ELIGANT-GN array being developed at ELI-NP was evaluated using dedicated GEANT4 simulation code. The array is designed to consist of 17 LaBr3:Ce and 17 CeBr3 detectors as well as 33 BC501A and 29 6Li-glass detectors. The energy and time responses of the detectors were studied giving information on gamma and neutron absolute detection efficiencies of the array. A planned day-one experiment regarding the gamma and neutron decay from GDR in 208Pb is discussed and, based on simulations, the data analysis procedure is proposed. The detection efficiencies as well as the count rates estimations are presented.
关键词： gamma-ray detection,neutron detection,GEANT4 simulations,gamma beam
更新于2025-09-10 09:29:36
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<i>Ab initio</i> response functions for Cherenkov-based neutron detectors
摘要： Neutron time-of-?ight diagnostics at the NIF were recently out?tted with Cherenkov detectors. A fused silica radiator delivers sub-nanosecond response time and is optically coupled to a microchannel plate photomultiplier tube with gain from ～1 to 104. Capitalizing on fast time response and gamma-ray sensitivity, these systems can provide better than 30 ps precision for measuring ?rst moments of neutron distributions. Generation of ab initio instrument response functions (IRFs) is critical to meet the <1% uncertainty needed. A combination of Monte Carlo modeling, benchtop characterization, and in situ comparison is employed. Close agreement is shown between the modeled IRFs and in situ measurements using the NIF’s short-pulse advanced radiographic capability beams. First and second moments of neutron spectra calculated using ab initio IRFs agree well with established scintillator measurements. Next-step designs offer increased sensitivity and time-response.
关键词： instrument response functions,neutron time-of-flight,NIF,Cherenkov detectors,Geant4 modeling
更新于2025-09-10 09:29:36