摘要
^(6)LiF/ZnS(Ag)闪烁屏是闪烁体型中子探测器的重要组成部分,其性能优劣会直接影响着探测器的应用,为了筛选出满足中国散裂中子源(CSNS)上工程材料中子衍射谱仪和能量分辨中子成像谱仪的中子探测器需求的高性能闪烁屏,利用中国散裂中子源的20号中子束线,系统研究了AST公司的多种^(6)LiF/ZnS(Ag)闪烁屏样品的相对热中子探测效率和中子信号积分谱,并通过刻度光测试系统中的光电倍增管得到这些样品的出射光产额,选取出用于闪烁体中子探测器的最佳闪烁屏材料。研究结果表明,^(6)LiF∶ZnS(Ag)质量分数比为1∶2,基底材料为塑料,闪烁屏厚度为300μm的AST-26139闪烁体样品性能较高,满足中子谱仪的中子探测器需求。
The^(6)LiF/ZnS(Ag)scintillation screen is key component of the scintillation neutron detector,and its performance will directly affect the application of the detector.In order to improve the performance of scintillator neutron detector and screen out a high-performance scintillator screen that meets the requirements of neutron detector for the engineering material diffraction and the energy resolution neutron imagining diffractometer on the China Spallation Neutron Source(CSNS),the No.20 neutron beam line of Chinese Spallation Neutron Source was used to systematically study the neutron detection efficiency and the light yield of different^(6)LiF/ZnS(Ag)scintillation screen samples with different thicknesses and different mass ratios from Britain’s Applied Scintillation Technologies(AST)manufacture.According to the results of neutron detection efficiency for these samples,the effects of^(6)LiF/ZnS(Ag)mass fraction ratio,thickness and substrate material type on the thermal neutron detection efficiency of^(6)LiF/ZnS(Ag)scintillator screen were analyzed by controlling variables.It is found that when the^(6)LiF∶ZnS(Ag)mass fraction ratio is 1∶2,the thickness is 300μm,the substrate material type is plastic,and the thermal neutron detection efficiency of the^(6)LiF/ZnS(Ag)scintillator screen is the highest.Theoretically,increasing the 6Li score or increasing the thickness of the scintillation screen can improve the thermal neutron detection efficiency of the^(6)LiF/ZnS(Ag)scintillator.According to the charge spectra of the emitted light of these samples,the calibrated photomultiplier tube was used to estimate the output light yield of the samples.The output light yield was compared with the number of scintillation photons generated by the scintillator.It is found that most of the photons generated by the scintillator are self-absorbed by the scintillator.For PMT,the output light yield difference between the sample and the sample is not large.On the basis of giving priority to the thermal neutron detection efficiency of the detector and taking into account the performance of the output light yield,a high-performance scintillation screen was comprehensively selected.The results show that the AST-26139 scintillation sample with^(6)LiF/ZnS(Ag)mass fraction ratio of 1∶2,plastic substrate and thickness of 300μm has the highest thermal neutron detection efficiency.The light yield from the surface of this screen is about 4.558×103.The AST-26139 was chosen as the best screen for the scintillation neutron detection.In engineering application,the“oblique incidence”structure for the^(6)LiF/ZnS(Ag)scintillation screen was designed to further improve the thermal neutron detection efficiency to meet the physical requirements of the scintillator neutron detector.
作者
蒋俊杰
黄畅
魏亚东
唐彬
于潜
周诗慧
蔡小杰
邓强
JIANG Junjie;HUANG Chang;WEI Yadong;TANG Bin;YU Qian;ZHOU Shihui;CAI Xiaojie;DENG Qiang(Dongguan University of Technology,Dongguan 523808,China;South China Normal University,Guangzhou 510006,China;Spallation Neutron Source Science Center,Dongguan 523803,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Lanzhou University,Lanzhou 730000,China;Zhengzhou University,Zhengzhou 450001,China;Southwest University of Science and Technology,Mianyang 621010,China;Shenzhen University,Shenzhen 518060,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2023年第8期1650-1657,共8页
Atomic Energy Science and Technology
基金
广东省基础与应用基础研究基金(2020B1515120025)。
