PGNAA系统中D-T中子管的慢化装置优化设计  

Optimal and Design of D-T Neutron Generator Moderation Setup in PGNAA System

作　　者：黄红[1,2] 李锐[2] 王琦标 庹先国[1,2,3] 杨剑波[1,2] 王旭[2] 

机构地区：[1]成都理工大学地球探测与信息技术教育部重点实验,成都610059 [2]成都理工大学地学核技术四川省重点实验室,成都610059 [3]四川理工学院,四川自贡643000

出　　处：《原子核物理评论》2016年第1期77-81,共5页Nuclear Physics Review

基　　金：四川省青年科技创新研究团队项目(2015TD0020);国家自然科学基金资助项目(41374112);国家高新技术研究发展计划资助项目(2012AA063501)~~

摘　　要：为了提高PGNAA系统中D-T中子管的中子慢化效率,获得更高的热中子产额,借助蒙特卡罗模拟,确定了以铅为中子反射层、5个聚乙烯层和铅层相互交替作为中子慢化层、碳化硼含量为5%的含硼聚乙烯作为中子吸收层以及铅作为γ屏蔽层的中子慢化装置模型。针对中子产额为3×107n/s的D-T中子管,该慢化装置出射方向低于5 e V的中子产额可达5.28×106n/s,占总中子产额的30.8%,有效提高了中子慢化效率。经过验证模拟结果能够满足实验要求。To improve the moderating efficiency of D-T Neutron Generator in PGNAA system, and get higher thermal neutron yield, the Monte Carlo code MCNP was used to optimize the moderation setup. The lead was selected as neutron reflector and gamma absorber, 5 polyethylene layers and 4 lead layers constituted the neutron moderator and 3% boron-doping polyethylene was selected as neutron absorber. For the yield of 3× 10^7 n/s D-T Neutron Generator, this moderation setup can provide a yield of lower than 5 eV of 5.28×10^6 n/s, accounting for 30.8% of total neutron yield, dramatically improves the moderating efficiency. It is proved that the simulation results can satisfy the requirement of PGNAA system by preliminary experimental verification.

关 键 词：PGNAA D—T中子管 中子慢化 蒙特卡罗 

分 类 号：TL84[核科学技术—核技术及应用]