面向个人剂量计校准的小尺度伽玛参考辐射模拟研究  

Personal dosimeter calibration based on minitype reference radiation

作　　者：钱易坤 冯鹏[2] 刘易鑫[1] 朱亚地 黄宇晨 张颂 何鹏[2] 魏彪[2] 毛本将[1] Qian Yikun;Feng Peng;Liu Yixin;Zhu Yadi;Huang Yuchen;Zhang Song;He Peng;Wei Biao;Mao Benjiang(China Academy of Engineering Physics,Mianyang 621900,China;College of Optoelectronics Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900 [2]重庆大学光电工程学院,重庆400044

出　　处：《强激光与粒子束》2021年第4期151-158,共8页High Power Laser and Particle Beams

基　　金：重庆大学中央高校基本科研业务费资助项目(2018CDGFGD0008);国家自然科学基金青年基金项目(11805111);国防科工局研究课题。

摘　　要：针对伽玛射线个人剂量计基于标准伽玛参考辐射进行校准时检定效率低、校准工作复杂和需要远程送检的关键技术问题,建构了1 Ci ^(137)Cs放射源小尺度参考辐射场物理模型,采用蒙特卡罗方法,研究了小尺度参考辐射场内的剂量分布、装置结构和待检剂量计变化导致散射射线对剂量场的影响,获得了待检剂量计形状、数量、类型和装置结构产生的散射伽玛射线对小尺度参考辐射量值定度的影响结果。研究结果表明,1 Ci ^(137)Cs可以为小尺度参考辐射辐射场检验点提供1.5 mSv/h的伽玛遂行剂量率,辐照个人剂量计载台直径30 cm束斑上的剂量率相对标准偏差约为0.48%。当载台厚度为20 mm时,散射射线对小尺度参考辐射检验点处剂量率值的影响率为3.27%,高于剂量计尺寸(1.62%)和剂量计数量(0.56%)的影响。Gamma-ray personal dosimeters are important tools for the radiation protection for workers.However,the current calibration method based on standard reference radiation has low verification efficiency,large calibration workload,and requires remote inspection.To solve the above problems,this paper attempts to apply the minitype reference radiation to the calibration of gamma-ray personal dosimeters.The Monte Carlo method is used to simulate the dose distribution in the minitype reference radiation field,the influence of scattering rays which are caused by the device structure and dosimeters in the dose field.The results show that 1 Ci ^(137)Cs can provide a dose rate of 1.5 mSv/h for the point of test,and the relative standard deviation of the dose rate at the point of test is about 0.48%.When the thickness of the stage is 20 mm,the influence rate of scattered rays on the dose rate value at the minitype reference radiation inspection point is 3.27%,which is higher than the influence of the size of the dosimeter(1.62%)and the number of dosimeters(0.56%).This paper provides a theoretical basis for in situ calibration to calibrate gamma-ray personal dosimeters.

关 键 词：个人剂量计 剂量量值定度 小尺度参考辐射 蒙特卡罗方法 遂行校准 

分 类 号：TL72[核科学技术—辐射防护及环境保护]