基于Bulk MicroMegas探测器的高能中子束空间分布测量  

Measurement of ultrafast neutron beam spatial distribution based on Bulk MicroMegas detector

作　　者：智宇 李沛玉 陈雷 宋金兴 孙鹏飞 周静[1] 赵明锐 贾世海 吝守龙 卢志永 邓桂华 靳尚泰 焦听雨 李世垚 秦茜 李玮[1] 胡守扬[1] 李笑梅[1] ZHI Yu;LI Peiyu;CHEN Lei;SONG Jinxing;SUN Pengfei;ZHOU Jing;ZHAO Mingrui;JIA Shihai;LIN Shoulong;LU Zhiyong;DENG Guihua;JIN Shangtai;JIAO Tingyu;LI Shiyao;QIN Qian;LI Wei;HU Shouyang;LI Xiaomei(Key Laboratory of Nuclear Data,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院核数据重点实验室,北京102413

出　　处：《航天器环境工程》2023年第3期276-282,共7页Spacecraft Environment Engineering

基　　金：国家重点研发计划项目(编号:2018YFE0104800);国家自然科学基金项目(编号:11875163);财政部稳定支持研究经费资助项目(编号:WDJC-2019-7,WDJC-2019-16)。

摘　　要：为验证中国原子能科学研究院(CIAE)自研的100 MeV回旋加速器中的高能中子束是否符合设计要求,利用自研的Bulk MicroMegas微结构气体探测器对该加速器中子场的空间分布进行了首次试验测量。首先通过模拟计算得到不同厚度聚乙烯(PE)转化膜对不同能量高能中子的转化效率、反冲质子的动能谱与角通量谱、反冲质子在Bulk MicroMegas气体探测器内的沉积能量谱以及中子与探测器结构物质反应产物占比等;然后利用Bulk MicroMegas探测器测量该回旋加速器产生的高能中子场在不同能量和距离处28个点位的中子通量分布,并根据通量分布计算中子束斑半径。结果表明,Bulk MicroMegas微结构气体探测器可以实现对高能中子场束斑边界成像,中子通量随束斑半径的变化关系符合常见束斑边界拟合函数;束斑半径测量结果与模拟计算结果接近。To verify whether the ultrafast neutron beam radii of the 100 MeV cyclotron developed by China Academy of Atomic Energy(CIAE)consists with the design requirements,the spatial distributions of the neutron field were measured experimentally for the first time using the self-developed Bulk MicroMegas micro-structured gaseous detector.Firstly,the transfer efficiencies of polyethylene(PE)converters with different thicknesses to ultrafast neutrons with different energies,the kinetic energy spectra and angular distributions of recoil protons,the deposition energy spectra of recoil protons in Bulk MicroMegas detector and the proportion of reaction products induced by incident neutrons reacted with detector structural materials were obtained through simulation calculations.Subsequently,the neutron flux distributions of the ultrafast neutron fields generated by the cyclotron at 28 positions were experimentally measured at different energies and distances using Bulk MicroMegas detector,and the beam radii profile was calculated according to the flux distribution.It is shown that the Bulk MicroMegas micro-structured gas detector can achieve the imaging of ultrafast neutron beam field boundary.The distribution of neutron flux at different distances to the beam center is in accordance with the commonly used beam boundary fitting functions.The measurement of beam radii is close to the simulation result.

关 键 词：中子束斑测量 Bulk MicroMegas气体探测器 聚乙烯转化膜 回旋加速器 模拟计算 

分 类 号：O572.2[理学—粒子物理与原子核物理] O242.2[理学—物理]