体源样品γ自吸收修正因子的蒙卡方法研究  

Gamma-ray self-attenuation correction for bulk samples by Monte-Carlo method

作　　者：秦超[1] 王德忠[1] 于文丹[2] 张适[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]核工业240研究所,沈阳110032

出　　处：《核技术》2011年第6期437-441,共5页Nuclear Techniques

基　　金：教育部科技创新工程重大项目培育基金(708036)资助

摘　　要：采用相对法测量环境辐射样品的γ能谱时,待测样品与标准样品对γ射线的自吸收程度差异会导致测量结果不准确,需对待测样品进行自吸收修正。本文通过点源试验方法得到HPGe探测器晶体的实际结构参数,在此基础上使用蒙特卡罗方法寻找体源自吸收率与同能量外置点源透射率间的函数关系。该方法综合考虑了体源基质成份和密度对自吸收修正因子的影响,可用于计算复杂基质体源样品的自吸收修正因子。When comparative method is adopted in gamma-ray spectrometry measurements of environmental samples,self-attenuation correction of under test samples is necessary,because of different self-attenuation coefficients of the reference and test samples.In this work,we investigate the self-attenuation correction by finding the relationship between the transmissivity and self-attenuation at the same photo-peak.The parameters of HPGe detector crystal were obtained by point source experiments.Based on these parameters,the relationship between the transmissivity and self-attenuation were studied by using the MCNP code.The differences of density and chemical composition were taken into account.This results show that method can be used to estimate the self-attenuation correction of complicated matrix samples.

关 键 词：环境体源样品 自吸收修正 透射率 γ能谱分析 

分 类 号：TL817[核科学技术—核技术及应用]