基于γ能谱反演的弱峰检测方法探讨  

Exploration of Weak Peak Detection Method Based on Gamma Spectra Deconvolution

作　　者：宋一鸣 周倩倩 陈晔 刘大海 周红召 肖无云 SONG Yiming;ZHOU Qianqian;CHEN Ye;LIU Dahai;ZHOU Hongzhao;XIAO Wuyun(State Key Laboratory of NBC Projection for Civilian,Beijing 102205,China)

机构地区：[1]国民核生化灾害防护国家重点实验室,北京102205

出　　处：《原子能科学技术》2024年第10期2228-2238,共11页Atomic Energy Science and Technology

摘　　要：为了改善低分辨率γ谱仪的分析性能,本文提出了一种通过基于能谱反演提升弱峰检测能力的新方法。利用SuperMC蒙特卡罗模拟计算,构建了NaI(Tl)谱仪响应矩阵;模拟了弱^(137)Cs源被^(60)Co康普顿散射连续坪干扰的能谱,实测了弱^(137)Cs能谱以及弱源^(137)Cs、^(152)Eu被^(60)Co康普顿散射连续坪干扰的能谱;采用L-R反演算法与对称零面积变换法相结合的方法检测弱峰。结果表明:经过反演后,^(137)Cs和^(152)Eu弱峰的显著度都明显改善,寻峰成功率也得到有效提升。这证明基于能谱反演的弱峰检测方法能有效提升低分辨率谱仪的弱峰检测能力。To improve the analytical performance of low resolution gamma spectrometers,a new method based on spectrum deconvolution to detect weak peaks was put forward.First of all,with SuperMC Monte Carlo simulation code,a geometric model matching the measured conditions was established,and then the system response matrices of a NaI(Tl) spectrometer was constructed Secondly,in order to ensure the accuracy of the gamma spectrum deconvolution,the nonlinear least square spectrum stabilization technique was applied to stabilize the measured spectra.Thirdly,the long time measured background spectrum was used for background deduction.And then the L-R deconvolution algorithm based on the system response matrices was used to improve the saliency of weak peaks.Finally,the symmetric zero-area transformation method was used to detect the weak peaks To verify the feasibility and applicability of the method,the gamma spectra of weak source ^(137)Cs disturbed by the Compton scattering continuum of high activity ^(60)Co were simulated,and the gamma spectra of weak ^(137)Cs and ^(152)Eu sources disturbed by the Compton scattering continuum of high activity^(60)Co were measured,as well as the gamma spectra of weak source ^(137)Cs.The simulated and measured results show that the significance of the weak peaks of ^(137)Cs and ^(152)Eu is markedly improved after deconvolution,and the peak-finding success rate increases greatly.Specifically,the peak-finding success rate of the weak peak ^(137)Cs increases from 25.9%to 42.0%,73.4%to 90.8%,and 61.4%to75.2%when it is overwhelmed by the environmental background,the Compton scattering of ^(60)Co and the statistical fluctuation,respectively.The peak-finding success rate of all weak peaks of ^(152)Eu disturbed by the Compton scattering continuum of different degrees,are improved to varying degrees with an increase of 6.0%to 97.0%.Especially,the peak-finding success rate of 295.9 keV weak peak of^(152)Eu is significantly elevated from 3.0%to 100%,as well as 1 528.1 keV weak peak of ^(152)Eu from6.1%t

关 键 词：弱峰检测 γ能谱反演 对称零面积变换法 

分 类 号：TL817[核科学技术—核技术及应用]