Variance analysis for passive neutron multiplicity counting  

作　　者：陈利高 龚建 王侃 谢奇林 刘晓波 白忠雄 鲁艺 荣茹 尹延朋 

机构地区：[1]Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics [2]Department of Engineering Physics,Tsinghua University

出　　处：《Nuclear Science and Techniques》2015年第2期54-58,共5页核技术（英文）

基　　金：Supported by the National Natural Science Foundation of China(No.11375158);Science and Technology Development Foundation of CAEP(No.2013B0103009)

摘　　要：Passive neutron multiplicity counting is widely used as a nondestructive assay technique to quantify mass of plutonium material. One goal of this technique is to achieve good precision in a short measurement time. In this paper, we describe a procedure to derive mass assay variance for multiplicity counting based on the threeparameter model, and analytical equations are established using the measured neutron multiplicity distribution.Monte Carlo simulations are performed to evaluate precision versus plutonium mass under a fixed measurement time with the equations. Experimental data of seven weapons-grade plutonium samples are presented to test the expected performance. This variance analysis has been used for the counter design and optimal gate-width setting at Institute of Nuclear Physics and Chemistry.Passive neutron multiplicity counting is widely used as a nondestructive assay technique to quantify mass of plutonium material. One goal of this technique is to achieve good precision in a short measurement time. In this paper, we describe a procedure to derive mass assay variance for multiplicity counting based on the threeparameter model, and analytical equations are established using the measured neutron multiplicity distribution.Monte Carlo simulations are performed to evaluate precision versus plutonium mass under a fixed measurement time with the equations. Experimental data of seven weapons-grade plutonium samples are presented to test the expected performance. This variance analysis has been used for the counter design and optimal gate-width setting at Institute of Nuclear Physics and Chemistry.

关 键 词：方差分析 计数 中子 多重数分布 无源 质量测定 测定技术 测量时间 

分 类 号：TL272[核科学技术—核燃料循环与材料]