海底原位PGNAA探测含水率对中子分布影响研究  

Research of the Effect of Water Content on the Distribution of Neutron by Using PGNAA for In-Situ Measurement

作　　者：徐阳 张庆贤[1] 葛良全[1] 张罡 白海涛 赵剑锟[1] 

机构地区：[1]成都理工大学地学核技术四川省重点实验室,成都610059

出　　处：《核电子学与探测技术》2017年第4期435-440,共6页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金(41374136);四川省科技支撑计划项目(2015RZ0010)资助

摘　　要：运用MC法模拟14 MeV快中子进入沉积物后的物理过程,得到了不同深度下沉积物中子能谱分布,分析了0~1 eV中子在沉积物中横、纵向分布规律以及含水率与Cl^-浓度对中子分布的影响,探讨了模拟条件下0~1 eV中子扩散的最大深度范围。结果表明:沉积物含水率对中子能谱分布和0~1 eV中子横、纵向分布均有显著影响,进行中子活化的最佳深度为2 cm处;0~1 eV中子扩散的最大深度范围为20~40 cm;海水中Cl^-浓度对中子吸收有影响但影响不显著。Monte Carlo method was used to simulate the physical process of 14 MeV fast neutrons after entering the sediments. The work obtained the neutron spectrums in different depths and the distribution of 0 ～ 1 eV neutrons in sediments, the influence of water contents and concentration of Cl^- on the distribution was analyzed and the range of maximum depth of 0～ 1 eV neutrons diffusion was discussed. The results show that water content has a significant influence on neutron energy spectrums, and the transverse and longitudinal distribution of 0 ～ 1 eV neutrons can also be affected. The optimum depth of neutron activation is 2 cm and the range of maximum depth of 0 ～ 1 eV neutrons diffusion is 20 cm ～ 40 cm. The concentration of Cl-in sea water has influence on neutron absorption, but the influence is not significant.

关 键 词：PGNAA 原位测量 海底沉积物 MC模拟 中子分布 

分 类 号：TL816[核科学技术—核技术及应用]