造钚率实验中γ射线自吸收修正研究  

Study on γ-ray self-absorption correction in plutonium production rates experiment

作　　者：韩子杰[1] 朱通华[1] 鹿心鑫[1] 安力[1] HAN Zijie;ZHU Tonghua;LU Xinxin;AN Li(Institute of Nuclear Physics and Chemistry,China Academy of Engineering,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所

出　　处：《核技术》2019年第10期65-69,共5页Nuclear Techniques

基　　金：国家自然科学基金(No.11775200、No.11575165);国家磁约束核聚变能发展研究专项(No.2015GB108006)资助~~

摘　　要：造钚率实验研究中需要测量贫化铀活化片发射的277.6 keVγ射线,活化片对此γ射线具有一定自吸收作用,需要对其进行修正。用面源法和体源法开展了自吸收理论的蒙德卡罗模拟计算,结果显示:探测距离为9 cm时,两种方法的偏差小于1.3%。用243Am面源、贫化铀活化片和HPGe探测器开展了277.6 keVγ射线自吸收实验研究,得到了不同厚度贫化铀活化片对277.6 keVγ射线自吸因子,实验结果与理论模拟偏差小于2.5%。[Background]γ-ray of 277.6 keV needs to be measured in plutonium production pates experiment.Selfabsorption effect of depleted uranium activated foils will affect the accuracy of the measuring results.[Purpose]This study aims to correct theγ-ray self-absorption effect of the activation foils in the plutonium production rates experiment.[Methods]First of all,plane source method and substance method were applied to MCNP(Monte Carlo N Particle Transport Code)to simulate the self-absorption theory,and results at various detection distance were obtained.Then experiments using 243Am plane radioactive source,depleted uranium foils and the HPGe detector were carried out to obtain self-absorption factors of 277.6 keV gamma-ray for depleted uranium activated foils with different thickness.[Results]The deviation of these two methods for simulation calculation of self-absorption factor is less than 1.3%at detection distance of 9 cm.The deviation between experimental measurement and simulation computation is less than 2.5%for depleted uranium foils with different thickness.[Conclusion]The reliability of theoretical simulation is proved by the verification between experiment and theory in this study.Hence the selfabsorption correction factors of samples under different measurement models can be obtained by theoretical simulation in the plutonium production rates experiment.

关 键 词：面源法 体源法 自吸收修正因子 

分 类 号：TL99[核科学技术—核技术及应用] O571.32[理学—粒子物理与原子核物理]