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Design and implementation of the monochromator shielding for the cold neutron spectrometers XINGZHI and BOYA
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作者 汪晋辰 刘娟娟 +6 位作者 徐大业 Florian Grünauer 郝丽杰 刘蕴韬 张红霞 程鹏 鲍威 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期96-102,共7页
An innovative monochromator shielding is designed and implemented for the cold neutron spectrometers XINGZHI and BOYA operated by Renmin University of China at China Advanced Research Reactor.Via Monte Carlo simulatio... An innovative monochromator shielding is designed and implemented for the cold neutron spectrometers XINGZHI and BOYA operated by Renmin University of China at China Advanced Research Reactor.Via Monte Carlo simulations and careful mechanical designs,a shielding configuration has been successfully developed to satisfy safety requirements of below 3μSv/h dose rate at its exterior,meanwhile fulfilling space,floor load and nonmagnetic requirements.Composite materials are utilized to form the sandwich-type shielding walls:the inner layer of boron carbide rubber,the middle layer of steel-encased lead and the outer layer of borated polyethylene.Special-shaped liftable shielding blocks are incorporated to facilitate a continuous adjustment of the neutron energy while preventing radiation leakage.Our work has demonstrated that by utilizing composite shielding materials,along with the sandwich structure and liftable shielding blocks,a compact and lightweight shielding solution can be achieved.This enables the realization of advanced neutron scattering instruments that provide expanded space of measurement,larger energy and momentum coverage,and higher flux on the sample.This shielding represents the first of its kind in neutron scattering instruments in China.Following its successful operation,it has been subsequently employed by other neutron instruments across the country. 展开更多
关键词 neutron scattering cold neutron spectrometer monochromator shielding sandwich shielding structure
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Simulation of Gamma-Ray and Neutron Spectrometers for Microsatellite Missions
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作者 Masayuki Naito Nobuyuki Hasebe +4 位作者 Junya Ishii José A.Matias-Lopes Valery V.Dmitrenko Christian Wohler Kyeong Ja Kim 《Journal of Geoscience and Environment Protection》 2018年第8期105-132,共28页
Microsatellites have recently opened windows of frequent and low cost missions for planetary exploration. The performance of gamma-ray and neutron spectrometers on future microsatellite missions is simulated to assess... Microsatellites have recently opened windows of frequent and low cost missions for planetary exploration. The performance of gamma-ray and neutron spectrometers on future microsatellite missions is simulated to assess the possibility of observation of hydrogen and major elements, given their concentration on the observation target. The measured elemental abundance will provide important geological constraints, and some of them may serve as space resources. Four different types of target bodies with various hydrogen concentrations in the range of 0 - 20,000 ppm are assumed as target compositions;Earth’s core, C-type, S-type and Martian meteorites. Gamma-ray and neutron emission rates show unique footprints that are related to the different elemental compositions. The starting point is the solid angle subtended between observation target and spectrometers that allow estimating the gamma-ray and neutron count rates emitted by the celestial bodies. In this work, three types of gamma-ray detectors;high-purity germanium (HPGe), CeBr3 and LaBr3(Ce), a neutron spectrometer combining a lithium glass scintillator with a boron loaded plastic scintillator and a dual mode spectrometer Cs2LiYCl6(Ce) (CLYC) are simulated, focusing on their observation backgrounds as a model case for microsatellite based measurements. The background count level of both gamma-ray (except for the LaBr3 detector) and neutron count rates was negligible under these particular conditions. The gamma-ray detectors were compared by the figure of merit, which was determined by their efficiency and energy resolution. It was found that each detector has unique advantages. The HPGe detector has the highest figure of merit due to its excellent energy resolution, whereas the CLYC detector is low in weight and power consumption due to its dual sensitivity to gamma-ray and neutron. The CeBr3 detector is an intermediate choice. The neutron count rates are calculated separately in three energy ranges, i.e. , thermal (<0.5 eV), epithermal (0.5 eV - 500 keV), and fast (>500 keV), as a function of the hydrogen concentration in the 0 - 20,000 ppm range. The thermal and epithermal neutron count rates are found to decrease with hydrogen concentration, while the fast neutron count rate increases with the target average atomic mass. The optimal detector should be decided by the mission restraints on mass, power consumption, and heat thermal design. 展开更多
关键词 Gamma-Ray Spectrometer neutron Spectrometer Microsatellite.High Purity Germanium CeBr3 LaBr3(Ce) CLYC
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Application of a BC501A Liquid Scintillation Detector with a Gain Stabilization System on the EAST Tokamak 被引量:1
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作者 彭星宇 陈忠靖 +5 位作者 杜腾飞 胡志猛 葛理健 陈金象 李湘庆 樊铁栓 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第1期23-29,共7页
A 2"×2"BC501A liquid scintillation detector with a gain stabilization system is developed and applied to neutron andγ-ray measurement on the EAST tokamak.Energy calibration of a liquid scintillator using a fas... A 2"×2"BC501A liquid scintillation detector with a gain stabilization system is developed and applied to neutron andγ-ray measurement on the EAST tokamak.Energy calibration of a liquid scintillator using a fast coincidence method is presented and compared with the Monte Carlo simulation.Determination of the proton light output function of the BC501A is presented.Results from dedicated experiments with an Am-Be neutron source,γsource and quasi-monoenergetic neutron beams,and from measurements on EAST tokamak are presented and discussed. 展开更多
关键词 gain stabilization BC501A neutron spectrometer pulsed light source EAST
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Calculation of Response Function for Bonner Sphere Spectrometer Based on Geant4
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作者 曹靖 蒋小菲 +2 位作者 蒋春雨 曹宏睿 阴泽杰 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第1期80-83,共4页
In order to make further studies on fusion neutron diagnosis on HL-2A /HL-2M,we have developed and succeeded in the calculation of the Response Function for a Bonner sphere spectrometer,which consists of eight polyeth... In order to make further studies on fusion neutron diagnosis on HL-2A /HL-2M,we have developed and succeeded in the calculation of the Response Function for a Bonner sphere spectrometer,which consists of eight polyethylene spheres with ^3He proportional counters inside.The response function of the Bonner spectrometer to neutrons is of fundamental importance for its neutron spectrum unfolding procedure and is directly related to the quality of the unfolded spectrum.In this paper,we calculated the response function to neutrons from 10^-9 MeV to100 MeV by Geant4.In order to test the accuracy of the Geant4 simulation,we apply it to measure an ^241Am-Be neutron source,and the measured neutron counts of the spectrometer and simulated counts are found to be highly consistent,with a relative error up to 9.3%.This has proven the calculation of the neutron response of the Bonner sphere spectrometer by Geant4 to be quite accurate. 展开更多
关键词 Bonner sphere spectrometer response function Geant4 HL-2A HL-2M multi-sphere spectrometer Monte Carlo ^241Am-Be neutron source
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Mechanical research and development of a monocrystalline silicon neutron beam window for CSNS
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作者 周良 屈化民 《Chinese Physics C》 SCIE CAS CSCD 2015年第9期69-73,共5页
The monocrystalline silicon neutron beam window is one of the key components of a neutron spectrom- eter. Monocrystalline silicon is brittle and its strength is generally described by a Weibull distribution due to the... The monocrystalline silicon neutron beam window is one of the key components of a neutron spectrom- eter. Monocrystalline silicon is brittle and its strength is generally described by a Weibull distribution due to the material inhomogeneity. The window is designed not simply according to the mean strength but also according to the survival rate. The total stress of the window is stress-linearized into a combination of membrane stress and bending stress by finite element analysis. The window is a thin circular plate, so bending deformation is the main cause of failure and tensile deformation is secondary and negligible. Based on the Weibull distribution of bending strength of monocrystalline silicon, the optimized neutron beam window is designed to be 1.5 mm thick. Its survival rate is 0.9994 and its transmittance is 0.98447, which meets both physical and mechanical requirements. 展开更多
关键词 neutron beam window monocrystalline silicon China Spallation neutron Source the survival rate neutron spectrometers
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First neutron spectrometry measurement at the HL-2A Tokamak 被引量:2
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作者 袁熙 张兴 +8 位作者 谢旭飞 陈忠靖 彭星宇 樊铁栓 陈金象 李湘庆 袁国梁 杨青魏 杨进蔚 《Chinese Physics C》 SCIE CAS CSCD 2013年第12期52-57,共6页
A compact neutron spectrometer based on the liquid scintillator is presented for neutron energy spectrum measurements at the HL-2A Tokamak. The spectrometer was well characterized and a fast digital pulse shape discri... A compact neutron spectrometer based on the liquid scintillator is presented for neutron energy spectrum measurements at the HL-2A Tokamak. The spectrometer was well characterized and a fast digital pulse shape discrimination software was developed using the charge comparison method. A digitizer data acquisition system with a maximum frequency of 1 MHz can work under an environment with a high count rate at HL-2A Tokamak. Specific radiation and magnetic shielding for the spectrometer were designed for the neutron spectrum measurement at the HL-2A Tokamak. For pulse height spectrum analysis, dedicated numerical simulation utilizing NUBEAM combined with GENESIS was performed to obtain the neutron energy spectrum. Subsequently, the transportation process from the plasma to the detector was evaluated with Monte Carlo calculations. The distorted neutron energy spectrum was folded with the response matrix of the liquid scintillation spectrometer, and good consistency was found between the simulated and measured pulse height spectra. This neutron spectrometer based on a digital acquisition system could be well adopted for the investigation of the auxiliary heating behavior and the fast-ion related phenomenon on different tokamak devices. 展开更多
关键词 compact neutron spectrometer digital signal processing beam-thermal neutron
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Design and performance analysis of a compact magnetic proton recoil spectrometer for DT neutrons 被引量:1
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作者 祁建敏 周林 蒋世伦 《Chinese Physics C》 SCIE CAS CSCD 2011年第4期374-380,共7页
A magnetic proton recoil (MPR) spectrometer is a novel instrument with superior performance, including high energy resolution, high count rate and good signal-to-noise ratio (SNR) for measurements of neutron spect... A magnetic proton recoil (MPR) spectrometer is a novel instrument with superior performance, including high energy resolution, high count rate and good signal-to-noise ratio (SNR) for measurements of neutron spectra from inertial confinement fusion (ICF) experiments and high power Tokomaks. In this work, the design of a compact MPR spectrometer (cMPR) was evaluated for deuteron-tritium (DT) neutron spectroscopy. The characteristics of the spectrometer were analyzed using 2-D beam transport simulations, 3-D particle transport calculations and Monte-Carlo simulations. Based on the theoretical results, an instrument design that satisfies special experimental requirements is proposed. The energy resolution and efficiency of the spectrometer are also evaluated. The results indicate that the proposed cMPR spectrometer would achieve a detection efficiency and energy resolution of approximately 10?8 and 4%, respectively, for DT neutrons. 展开更多
关键词 magnetic proton recoil (MPR) COMPACT neutron spectrometer DT neutron
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Simulation of the response functions of an extended range neutron multisphere spectrometer using FLUKA 被引量:1
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作者 王攀峰 丁亚东 +3 位作者 王庆斌 马忠剑 郭思明 李冠稼 《Chinese Physics C》 SCIE CAS CSCD 2015年第7期37-41,共5页
In this paper, the distribution of radiation field in the CSNS spectrometer hall at Dongguan, China, was simulated by the FLUKA program. The results show that the radiation field of the high energy proton accelerator ... In this paper, the distribution of radiation field in the CSNS spectrometer hall at Dongguan, China, was simulated by the FLUKA program. The results show that the radiation field of the high energy proton accelerator is dominated by neutron radiation, with a broad range of neutron energies, spanning about eleven orders of magnitude.Simulation and calculation of the response functions of four Bonner spheres with a simplified model is done with FLUKA and MCNPX codes respectively, proving the feasibility of the FLUKA program for this application and the correctness of the calculation method. Using the actual model, we simulate and calculate the energy response functions of Bonner sphere detectors with polyethylene layers of different diameters, including detectors with lead layers, using the FLUKA code. Based on the simulation results, we select eleven detectors as the basic structure for an Extended Range Neutron Multisphere Spectrometer(ERNMS). 展开更多
关键词 neutron multisphere spectrometer neutron spectrum energy response FLUKA 3He-filled spherical proportional counter
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Prototype of a large neutron detector based on MWPC 被引量:1
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作者 TIAN LiChao QI HuiRong +11 位作者 SUN ZhiJia WANG YanFeng ZHANG Jian LIU RongGuang ZHAO YuBin ZHANG HongYu ZHAO DongXu DONG Jing XIE Wan YANG GuiAn OUYANG Qun CHEN YuanBo 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第11期2049-2053,共5页
A prototype of large-area position sensitive neutron detector was designed and constructed according to the requirements of the Small-Angle Scattering spectrometer of China Spallation Neutron Source(CSNS).The detector... A prototype of large-area position sensitive neutron detector was designed and constructed according to the requirements of the Small-Angle Scattering spectrometer of China Spallation Neutron Source(CSNS).The detector was based on the 3He neutron convertor and MWPC with an effective area of 650 mm×650 mm.A prototype was completed and tested with 55Fe X-ray.The high-pressure vessel was designed and constructed with high-strength aluminum alloy.A position resolution of about 4.6mm×2.3 mm(FWHM)and efficiency>65%for neutrons with wavelength of 1.8?was determined after the operational gas filled. 展开更多
关键词 neutron prototype operational spectrometer completed readout proton filled chamber FWHM
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Experimental validation of a Tokamak neutron spectrometer based on Bonner spheres
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作者 曹靖 蒋春雨 +1 位作者 曹宏睿 阴泽杰 《Chinese Physics C》 SCIE CAS CSCD 2015年第8期62-65,共4页
In order to realize real-time fusion neutron spectrum diagnosis for the HL_2A Tokamak, a Bonner Sphere Spectrometer (BSS) array has been developed, consisting of eight polyethylene spheres (PS) with embedded aHe p... In order to realize real-time fusion neutron spectrum diagnosis for the HL_2A Tokamak, a Bonner Sphere Spectrometer (BSS) array has been developed, consisting of eight polyethylene spheres (PS) with embedded aHe proportional counters. To validate its spectrometric capability, spectrum measurement of an 241Am-Be neutron source was carried out and is described. The Monte Carlo code Geant4 was used to calculate the response functions, taking this interference into consideration. Finally, the neutron spectrum was unfolded in the energy range from 10-9 MeV to 20 MeV. The unfolded spectrum has remarkable consistency with the ISO 8529-1 standard 2alAm-Be neutron spectrum which is a preliminary demonstration that this BSS is reliable and practical. 展开更多
关键词 neutron spectrometer 241Am-Be source GEANT4 TOKAMAK Bonner sphere HL_2A multi-sphere
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Performance study of the neutron-TPC
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作者 黄孟 李玉兰 +8 位作者 牛莉博 邓智 程晓磊 何力 章洪燕 傅楗强 闫洋洋 蔡一鸣 李元景 《Chinese Physics C》 SCIE CAS CSCD 2017年第2期136-142,共7页
Fast neutron spectrometers will play an important role in the future of the nuclear industry and nuclear physics experiments, in tasks such as fast neutron reactor monitoring, thermo-nuclear fusion plasma diagnostics,... Fast neutron spectrometers will play an important role in the future of the nuclear industry and nuclear physics experiments, in tasks such as fast neutron reactor monitoring, thermo-nuclear fusion plasma diagnostics,nuclear reaction cross-section measurement, and special nuclear material detection. Recently, a new fast neutron spectrometer based on a GEM(Gas Electron Multiplier amplification)-TPC(Time Projection Chamber), named the neutron-TPC, has been under development at Tsinghua University. It is designed to have a high energy resolution,high detection efficiency, easy access to the medium material, an outstanding n/γ suppression ratio, and a wide range of applications. This paper presents the design, test, and experimental study of the neutron-TPC. Based on the experimental results, the energy resolution(FWHM) of the neutron-TPC can reach 15.7%, 10.3% and 7.0% with detection efficiency higher than 10^-5 for 1.2 Me V, 1.81 Me V and 2.5 Me V neutrons respectively. 展开更多
关键词 fast neutron spectrometer time projection chamber track reconstruction
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Measurements of neutron energy spectra of 9Be(d,n)10B reaction with a thick beryllium target
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作者 Shuang-Jiao Zhang Zhi-Jie Hu +15 位作者 Zhi-Ming Hu Chao Han Xiao-Hou Bai Chang-Qi Liu Chang Huang Qin Xie Dong-Ying Huo Kang Wu Yang-Bo Nie Yan-Yan Ding Kai Zhang Yu Zhang Zhi-Yong Deng Rui Guo Zheng Wei Ze-En Yao 《Chinese Physics C》 SCIE CAS CSCD 2021年第2期398-405,共8页
Novel measurements of the neutron energy spectra of the 9Be(d,n)10B reaction with a thick beryllium target are performed using a fast neutron time-of-flight(TOF)spectrometer for the neutron emission angles θ=0°a... Novel measurements of the neutron energy spectra of the 9Be(d,n)10B reaction with a thick beryllium target are performed using a fast neutron time-of-flight(TOF)spectrometer for the neutron emission angles θ=0°and 45°,and the incident deuteron energies are 250 and 300 keV,respectively.The neutron contributions from the 9Be(d,n)10B reaction are distributed relatively independently for the ground state and the first,second,and third excited states of 10B.The branching ratios of the 9Be(d,n)10B reaction for the different excited states of 10B are obtained for the neutron emission angles θ=0°and 45°,and the incident deuteron energies are 250 and 300 keV,respectively.The branching ratio of the 9Be(d,n)10B reaction for the third excited state decreases with increase in the incident deuteron energy,and the branching ratios for the ground state and the second excited state increase with increase in the neutron emission angle. 展开更多
关键词 neutron energy spectrum branching ratio 9Be(d n)10B reaction neutron time-of-flight spectrometer
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Design of a neutron-TPC prototype and its performance evaluation based on an alpha-particle test
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作者 黄孟 李玉兰 +7 位作者 牛莉博 李金 邓智 何力 章红燕 程晓磊 傅楗强 李元景 《Chinese Physics C》 SCIE CAS CSCD 2015年第8期73-80,共8页
A neutron-TPC (nTPC) is being developed for use as a fast neutron spectrometer in the fields of nuclear physics, nuclear reactor operation monitoring, and thermo-nuclear fusion plasma diagnostics. An nTPC prototype ... A neutron-TPC (nTPC) is being developed for use as a fast neutron spectrometer in the fields of nuclear physics, nuclear reactor operation monitoring, and thermo-nuclear fusion plasma diagnostics. An nTPC prototype based on a GEM-TPC (Time Projection Chamber with Gas Electron Multiplier amplification) has been assembled and tested using argon-hydrocarbon mixture as the working gas. By measuring the energy deposition of the recoil proton in the sensitive volume and the angle of the proton track, the incident neutron energy can be deduced. A Monte Carlo simulation was carried out to analyze the parameters affecting the energy resolution of the nTPC, and gave an optimized resolution under ideal conditions. An alpha particle experiment was performed to verify its feasibility, and to characterize its performance, including energy resolution and spatial resolution. Based on the experimental measurement and analysis, the energy resolution (FW-HM) of the nTPC prototype is predicted to be better than 3.2% for 5 MeV incident neutrons, meeting the performance requirement (FWHM〈5%) for the nTPC prototype. 展开更多
关键词 fast neutron spectrometer Monte Carlo simulation neutron energy resolution
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Track reconstruction based on Hough-transform for nTPC
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作者 牛莉博 李玉兰 +2 位作者 黄孟 何彬 李元景 《Chinese Physics C》 SCIE CAS CSCD 2014年第12期50-54,共5页
A GEM-TPC prototype, which will be used as a fast neutron spectrometer based on the recoil proton method, is designed and being constructed in Tsinghua University. In order to derive the recoil angle of the recoil pro... A GEM-TPC prototype, which will be used as a fast neutron spectrometer based on the recoil proton method, is designed and being constructed in Tsinghua University. In order to derive the recoil angle of the recoil proton, tracks of recoil proton in the TPC sensitive volume must be reconstructed. An algorithm based on Houghtransform for track finding and least square method for track fitting was developed in this paper. Based on the Monte Carlo simulation data given by Geant 4, a detailed track reconstruction process was introduced and the spectrum of induced fast neutron was derived here. The results show that the algorithm was effective and high-performance.With the recoil angle of the proton less than 30°, a 4.4% FWHM neutron energy resolution was derived for 5 Me V induced fast neutron, and the detection efficiency was about 2×10^-4. 展开更多
关键词 fast neutron spectrometer GEM-TPC Hough-transform track reconstruction GEANT4
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