靶室散射对ICF中子产额用铅活化法测量准确性的影响  

Effect of target chamber-scattered neutrons on ICF neutron yield measurement accuracy by Pb activation

作　　者：徐家云[1] 白立新[1] 张一云[1] 吴丽萍[1] 冯杰[2] 杨存榜[2] 

机构地区：[1]四川大学物理科学与技术学院,四川成都610064 [2]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《强激光与粒子束》2004年第9期1143-1147,共5页High Power Laser and Particle Beams

基　　金：国家863计划项目资助课题

摘　　要：　通过用MCNP4B程序计算在铅样品中的来源于靶室散射中子的注量和来源于未经靶室散射的源中子注量,结合由ENDF/B Vi评价数据库给出的中子铅活化核反应截面,得到了在铅样品周围存在不同屏蔽材料时,神光Ⅱ靶室散射对聚变中子产额用铅活化法测量准确性影响小于1‰的结果。Measuring ICF neutron yield by Pb activation is performed in the target chamber, but calibrating the Pb detect system using an accelerator neutron source is not performed in the target chamber. The difference between the measuring environment and the calibrating environment will affect the measurement accuracy, for the neutrons scattered by the target chamber will contribute to the production of radionuclide 207mPb which emits detectable γ radiations. In this paper, by Monte-Carlo method, the effect on the measurement accuracy is calculated and the result is less than 1‰. This effect is defined as the ratio of the number of 207mPb(Ns) generated from the target chamber-scattered neutron activation to the number of 207mPb(N) generated without target chamber existing. The target chamber used in the calculation is the Shengguang II chamber in China. The calculated result shows that the effect is very small and negligible.

关 键 词：ICF中子产额 铅活化法 靶室散射 Γ射线 蒙特卡罗方法 

分 类 号：TL816.3[核科学技术—核技术及应用] TL822.3