反冲质子磁谱仪的性能模拟与分析  

Performance Simulation and Analysis of Magnetic Proton Recoil Neutron Spectrometer

作　　者：张建福 张小东[1,2] 张显鹏 刘金良[1,2] ZHANG Jian-fu;ZHANG Xiao-dong;ZHANG Xian-peng;LIU Jin-liang(State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Xi’an710024,China;Northwest Institute of Nuclear Technology,Xi’an710024,China)

机构地区：[1]强脉冲辐射环境模拟与效应国家重点实验室,西安710024 [2]西北核技术研究所,西安710024

出　　处：《现代应用物理》2018年第4期54-60,共7页Modern Applied Physics

基　　金：国家自然科学基金资助项目(11175141)

摘　　要：采用蒙特卡罗和束流光学方法,对反冲质子磁谱仪系统的中子-反冲质子输运及反冲质子在磁场中的偏转和聚焦的全过程进行了物理建模,基于Matlab平台,开发了带电粒子输运模拟计算程序,模拟了反冲质子磁谱仪系统的性能参数,获得了不同参数条件下反冲质子在焦平面上的空间分布、中子能量分辨率及中子探测效率。结果表明,反冲质子磁谱仪的中子能量分辨率和中子探测效率是对立性较强的2个性能参数,主要决定于反冲聚乙烯靶尺寸和反冲质子准直器尺寸,二极分析磁铁的磁感应强度对中子能量分辨率和中子探测效率的影响不大,但会影响反冲质子磁谱仪的紧凑性。对能量为14MeV的氘氚聚变中子,磁谱仪的中子能量分辨率小于1%时,中子探测效率可达10^(-8)cm^2。A model of Monte Carlo simulation is set up to determine the performance of the magnetic proton recoil(MPR)neutron spectrometer by using Matlab toolkit.The performance characteristics of the MPR spectrometer,including the recoil proton distribution,the neutron detection efficiency,and the neutron energy resolution,are calculated by using the Monte Carlo model.The neutron detection efficiency and the energy resolution of the MPR spectrometer are mainly determined by the combination of the parameters,including the proton energy loss in the polyethylene foil,the proton collimator,and the performance of the dipole magnet.The neutron detection efficiency and the energy resolution are the interrelated performance characteristics.The dipole magnetic field strength has little effects on the neutron detection efficiency and the energy resolution,but it is closely related with the dimension of the MPR spectrometer.The MPR spectrometer can achieve neutron detection efficiency about 10-8 cm 2 at the energy resolution less than 1%for measuring DT neutrons with the energy of 14 MeV.

关 键 词：反冲质子磁谱仪 蒙特卡罗模拟 中子探测效率 中子能量分辨率 氘氚中子 

分 类 号：O571[理学—粒子物理与原子核物理]