基于NaI(Tl)伽马谱仪的反演分析法在海水放射性探测中的应用  

Application of Inversion Analysis Method Based on NaI(Tl)Spectrometer in Seawater Radioactivity Detection

作　　者：毕海杰 张颖颖 吴丙伟 冯现东 石岩 BI Haijie;ZHANG Yingying;WU Bingwei;FENG Xiandong;SHI Yan(Qilu University of Technology(Shandong Academy of Sciences),Institute of Oceanographic Instrumentation,Qingdao 266061,China;Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology,Qingdao 266061,China;National Engineering and Technological Research Center of Marine Monitoring Equipment,Qingdao 266061,China)

机构地区：[1]齐鲁工业大学(山东省科学院)海洋仪器仪表研究所,山东青岛266061 [2]山东省海洋监测仪器装备技术重点实验室,山东青岛266061 [3]国家海洋监测设备工程技术研究中心,山东青岛266061

出　　处：《海洋科学进展》2024年第2期349-357,共9页Advances in Marine Science

基　　金：山东省自然科学基金重点项目(ZR2020KE003);国家自然科学基金项目(41606111);崂山实验室山东省专项经费“问海计划”项目(2021WHZZB0202和2022QNLM040004-1);泰山学者资助项目。

摘　　要：伴随着核能的快速发展和应用,海洋放射性环境安全监测受到了越来越多的关注。因具有成本低、功耗低、探测效率高等优点,NaI(Tl)伽马谱仪成为海洋放射性自动连续监测主要应用的仪器。但是,该谱仪探测分辨能力尚存在不足,导致核素甄别和定量检测存在困难。为了解决该困难,本研究采用理论计算、仿真模拟和实验测量等技术手段,开展基于反演分析的海水伽马能谱处理分析方法研究。研究结果表明:仿真实验中经过反演分析法计算的重构谱线的分辨率得到大幅改善,与仿真能谱中核素的道址和活度的参考值相比,重构谱线的^(134)Cs、^137Cs、^(60)Co和^(40)K核素峰的道址误差在2道以内,活度计算误差在4%以内。在位于青岛的海洋科学实验站进行的海水现场实验结果表明反演分析法对_(40)K核素的活度分析结果为1.218×10^(4) Bq·m^(-3)。该方法能够有效解决NaI(Tl)伽马谱仪探测分辨能力不足的问题,实现准确的海水放射性核素分析。With the rapid development and wide application of nuclear energy technology,more and more attention has been paid to the safety monitoring of marine radioactive environment.Due to its advantages of low cost,low power consumption,and high detection efficiency,the NaI(Tl)Gamma spectrometer has become the main application instrument for automatic and continuous monitoring of marine radioactivity.However,the detection resolution capability of this spectrometer is insufficient,which leads to difficulties in nuclide identification and quantitative detection.In order to solve this problem,this study adopts technical means such as theoretical calculation,simulation and experimental measurement to conduct research on the processing and analysis method of seawater Gamma spectrum based on inversion analysis.The results show that the resolution of the reconstructed spectral lines calculated through inversion analysis in the simulation experiment has been significantly improved.Compared with the reference values of the channel address and activity of nuclides in the simulated spectrum,the channel address errors of ^(134)Cs,^(137)Cs,^(60)Co,and 40K nuclide peaks in the reconstructed spectral lines are within 2 channels,and the calculation error of activity is within 4%.The results of in-situ seawater experiments conducted at the Marine Science Experimental Station in Qingdao showed that the activity analysis of 40K nuclides using the inversion analysis method yielded a result of 1.218×10^(4) Bq·m^(-3).This method can effectively solve the problem of insufficient detection resolution of the NaI(Tl)Gamma spectrometer and achieve accurate analysis of radionuclides analysis in seawater.

关 键 词：海水放射性监测 NaI(Tl)伽马谱仪 反演分析 响应矩阵 

分 类 号：X837[环境科学与工程—环境工程]