不同厚度ST401中子能谱响应测量与分析  

Measurement and analysis of neutron spectrum responses of ST401 scintillators with different thickness

作　　者：李阳[1] 张艳红[1] 盛亮[1] 张美[1] 姚志明[1] 段宝军[1] 赵吉祯[1] 郭泉 严维鹏 李国光 胡佳琦 李豪卿 李郎郎 Li Yang;Zhang Yan-Hong;Sheng Liang;Zhang Mei;Yao Zhi-Ming;Duan Bao-Jun;Zhao Ji-Zhen;Guo Quan;Yan Wei-Peng;Li Guo-Guang;Hu Jia-Qi;Li Hao-Qing;Li Lang-Lang(State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi’an 710024,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]西北核技术研究所,强脉冲辐射模拟与效应全国重点实验室,西安710024 [2]清华大学工程物理系,北京100084

出　　处：《物理学报》2024年第23期89-96,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12175183);国防科技卓越青年科学基金(批准号:JQZQ021901)资助的课题.

摘　　要：在MeV能段脉冲中子测量中,塑料闪烁体是应用最为广泛的一种材料,其中子能谱响应是脉冲中子能谱测量所需的关键数据.基于中国散裂中子源白光中子束线,使用飞行时间法测量了0.5—10 mm共5种不同厚度塑料闪烁体ST401对0.5—100 MeV能段的中子能谱响应曲线,分析了束内伽马、伽马闪产生的闪烁体慢成分和中子源脉宽对中子能谱响应的影响.受有限体积闪烁体边界效应影响,不同厚度中子能谱响应曲线形状接近对数曲线,质子逃逸是闪烁体能谱响应曲线偏离线性的主要原因,闪烁体越厚,偏离线性的中子能量越高.In the measurement of pulsed neutrons in the MeV energy range,plastic scintillators are one of the most widely used materials,and their neutron energy spectrum responses are key data of pulsed neutron energy spectrum measurement.The neutron energy spectrum responses of ST401 plastic scintillators with 5 different thickness values ranging from 0.5 to 10 mm in an energy range from 0.5 MeV to 100 MeV are measured by using the time-of-flight(TOF)method on the white neutron source(WNS)beamline of the China Spallation Neutron Source(CSNS).The effects of in-beam gamma rays,the gamma flash produced slow component of scintillator,and the pulse width of the neutron source on the measurement of neutron spectrum response are analyzed.Owing to the boundary effect of the finite volume of the scintillator,the neutron energy spectrum response curves of ST401 with different thickness values present approximately logarithmic shape,and proton escape is the main reason for the deviation of the curve from linearity.The thicker the scintillator,the higher the neutron energy deviates from linearity.

关 键 词：塑料闪烁体 中子能谱响应 边界效应 

分 类 号：TL812[核科学技术—核技术及应用] O571.54[理学—粒子物理与原子核物理]