摘要
非破坏分析方法γ能谱法测量238U是通过测量它的子体^(214)Pb、^(214)Bi、^(234)Th或其他子体的活度含量来实现的,其测量准确度取决于238U系列是否处于放射性平衡状态。然而,某些特殊铀矿地质样品或其他样品中^(238)U系列并不一定处于平衡状态,这就使得γ能谱法测定此类样品存在测定结果偏离真值的风险。通过研究铀衰变系列总α放射性比活度和各个γ核素放射性比活度的关系,建立了铀系列放射性平衡的判断模型,探索了总α-γ能谱法和两次γ测量法,提高了测定的准确度,两次γ测量法与化学法相比,测量结果相对偏差小于20%。
Nondestructive assay(NDA)like gamma spectrometry is used to measure ^(238)U by measuring the activity content of its daughters such as ^(214)Pb or ^(214)Bi or ^(234)Th or other daughters.The accuracy of the measurement depends on whether the radioactivity of the 238U series is in equilibrium.However,238U Series in some special uranium geological samples or other samples are not always in equilibrium,which makes the determination results of such samples deviate from the true value.This paper studied the relationship between the grossαspecific activity of uranium decay series and the specific activity of eachγnuclide,established the judgment model of radioactive equilibrium of uranium series,explored the grossα-γspectrometry method and two-stepγspectrometry measurement method,and have improved the accuracy of the measurement.Compared with chemical method,the relative deviation of two-stepγspectrometry measurement method is less than 20%.
作者
刘立坤
李多宏
周志波
王岚
武朝辉
李伯平
初泉丽
LIU Likun;LI Duohong;ZHOU Zhibo;WANG Lan;WU Zhaohui;LI Boping;CHU Quanli(State Nuclear Security Technology Center,Beijing 102401,China;Beijing Research Institute of Uranium Geology,Beijing 100029,China)
出处
《铀矿地质》
CAS
CSCD
2021年第4期728-735,共8页
Uranium Geology
关键词
非平衡体系
平衡判断法
两次γ测量法
总α-γ能谱法
disequilibrium series
equilibrium judgment method
two-step measurement method
grossα-γ-spectrometry method
