NaI(Tl)就地探测器测量海水中^(137)Cs与^(131)I的蒙特卡罗模拟研究  

Monte Carlo Modeling of NaI(Tl)Detectors for Nuclides ^(137)Cs and ^(131)I in Seawater

作　　者：潘孝兵[1,2] 朱养妮[1] 余小任[1] 全林[3] 曲广卫 

机构地区：[1]西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室,西安710024 [2]西安交通大学核科学与技术学院,西安710049 [3]北京跟踪与通信技术研究所,北京100094 [4]陕西卫峰核电子有限公司,西安710118

出　　处：《现代应用物理》2014年第3期177-181,共5页Modern Applied Physics

摘　　要：利用蒙特卡罗模拟程序MCNP研究了NaI(Tl)探测器对海水中137Cs、131I的比计数率响应情况;计算了NaI(Tl)探测器对不同半径海水球体源中137 Cs与131I的比计数率响应曲线;分析了探测器防水套筒、NaI(Tl)晶体尺寸与结构、射线能量等因素对比计数率响应的影响;拟合了3R3型、5R5型NaI(Tl)探测器最大比计数率ymax及有效探测距离D。防水套筒模型与裸晶体简化模型的计算结果对比表明,裸晶体模型会给计算带来明显的偏差,应在模型设计时,考虑探测器结构,构建更精确的模型。A NaI（Tl）detector with waterproof sleeve used for in-situ measurement of specif-ic activity of artificial radionuclides of 137 Cs and 131 I in seawater was modeled with MCNP, and the specific counting rate curves of the detector with and without waterproof sleeve were calculated with different source radii.The effects of the detector structure,the size of the NaI（Tl） crystal,and the γ-ray energy were investigated.The maximum specific counting rate and effective detection range were calculated and compared for the detectors of 3×3 in-ches and 5×5 inches with and without waterproof sleeve,and the results show that the sim-plified naked crystal model would bring more deviation from the true results.

关 键 词：MCNP NAI(TL)探测器 137Cs 131I 就地测量 

分 类 号：P631[天文地球—地质矿产勘探]