自然γ测井中MC法模拟探测器探测深度  

The Calculation of the Detection Depth in Natural Gamma Logging:A MCNP Study

作　　者：刘珉强 杜川华[1] 赵洪超[1] 汪宏年[2] LIU Min-qiang;DU Chuan-hua;ZHAO Hong-chao;WANG Hong-nian(Institute of electrical engineering,China Academy of Engineering Physics,Mianyang Sichuan 621999,China;College of Physics,Jilin University,Changchun Jilin 130012,China)

机构地区：[1]中国工程物理研究院电子工程研究所,四川绵阳621999 [2]吉林大学物理学院,吉林长春130012

出　　处：《核电子学与探测技术》2020年第1期167-173,共7页Nuclear Electronics & Detection Technology

基　　金：装备预研领域基金(6140A24020105,6140A24010301);中国科学院战略性先导科技专项(XDA14020102)资助。

摘　　要：采用MCNP模拟计算了不同γ射线能量或矿层密度下探测器的探测深度,研究γ射线能量或矿层密度的变化对探测器探测深度的影响.模拟结果表明:探测器探测深度与γ射线能量成正比,与矿层密度成反比;当矿层厚度小于探测器探测深度时,采取放射性成像分析地层信息的方法存在较大误差.并且通过对模型井进行放射性成像的方式阐释了此方法的可靠性.对于实验井或模型井的矿层厚度选择,可以用MCNP模拟的方法计算探测深度作为参考.The detection depths for different γ-ray energies or mineral layer densities,for a one and the same detector,have been calculated using MCNP code.The simulation results show that the detection depth is directly proportional to the γ-ray energy and inversely proportional to the density of the mineral layer;When the thickness of mineral layer is less than the depth of the detector,there is a big error in using the method of radioactive imaging to analyze the formation information.And the reliability of the method,which is used to calculate the detection depth,is illustrated by radiographically imaging the model well.Therefore,the detection depth calculated by MCNP,as a reference,can be used to select the thickness of the mineral layer in the experimental or model Wells.

关 键 词：MCNP 探测器探测深度 γ射线强度 矿层厚度 γ射线能量 矿层密度 

分 类 号：O571.33[理学—粒子物理与原子核物理]