点源模型刻度就地谱仪角度修正因子影响研究  

The Study on the Effect of Angle Correction Factor of in Situ Spectrometer by Point Source Model

作　　者：杜云武[1] 朱杰[1] 王茜[1] 王亮[1] 欧阳均[1] 舒奕嘉 张红帆 李元东 DU Yunwu;ZHU Jie;WANG Qian;WANG Liang;OU Yang Jun;SHU Yijia;ZHANG Hongfan;LI Yuandong(Sichuan Provincial Radiation Environment Management and Monitoring Center Station,Chengdu,610031,China)

机构地区：[1]四川省辐射环境管理监测中心站,成都610031

出　　处：《核电子学与探测技术》2023年第5期964-974,共11页Nuclear Electronics & Detection Technology

基　　金：四川省生态环境厅2022年度生态环境保护科研课题:821厂核设施外围辐射环境监督性监测数据分析及评价,项目编号:2022HB17。

摘　　要：对于核与辐射事故应急,就地谱仪现场监测辐射事故污染的程度和范围,利于现场指挥快速科学决策。应急准备的一项重要工作是就地谱仪准确校准角度修正因子及其相对偏差及其海拔高度适宜性。采用MCNP模拟计算和试验校准,建立一种就地P型高纯锗谱仪探测器模型。根据就地谱仪校准角度修正因子的点源模型,理论计算其初级γ射线注量率和MCNP模拟计算探测器高度1 m、2 m、3 m、11种入射角和11种γ能量的点源探测效率,以及500 m、2 261 m、3 650 m海拔高度,探测器高度1 m、11种入射角、3种γ能量的点源探测效率和初级γ射线注量率,进而分析其角响应因子、角度修正因子和相对标准偏差。研究结果表明,点源距离大于1 m情况下,其角响应因子和角度修正因子相对标准偏差小于4.35%;海拔高度500~3 650 m情况下,其角响应因子和角度修正因子相对标准偏差小于1.2%;其角度修正因子是能量的自然对数的分段函数,在120~3 000 keV为线性函数,在45~120 keV为指数函数。According to the point source model of the calibration angle correction factor of the local spectrometer,the primary ray injection rate was calculated theoretically and the detection efficiency of the point source with the detector height of 1,2,3 m,11 kinds of incidence angles and 11 kinds of energy was calculated by MCNP simulation.And the point source detection efficiency and primary gamma ray fluence rate of 500,2261,3650 m altitude,detector height 1 m,11 kinds of incidence angles,3 kinds of energy.Then the angular response factor,angle correction factor and relative standard deviation are analyzed.The results show that the relative standard deviation of angular response factor and angle correction factor is less than 4.35%when the point source distance is greater than 1 m.At altitudes ranging from 500 to 3650 m,relative standard deviation of angular response factor and angle correction factor is less than 1.2%.The angle correction factor is a piecewise function of the natural logarithm of energy,a linear function from 120 keV to 3000 keV,and an exponential function from 45 keV to 120 keV.

关 键 词：就地谱仪 角响应因子 角度修正因子 相对标准偏差 

分 类 号：TL99[核科学技术—核技术及应用]