极大似然法反演γ特征峰位的能力研究  

Study on the ability of maximum likelihood method to retrieve the position of γ characteristic peaks

作　　者：陈伟[1] 苏川英[1] 冯天成[1] 刘文彪[1] 田自宁[1] CHEN Wei;SU Chuanying;FENG Tiancheng;LIU Wenbiao;TIAN Zining(Northwest Institute of nuclear Technology, Xi'an 710024, China)

机构地区：[1]西北核技术研究所,西安710024

出　　处：《核技术》2018年第12期66-71,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.11405134)资助~~

摘　　要：极大似然法反演γ能谱可有效提高γ能谱能量分辨率,为观察该方法反演γ特征峰位的能力,使用蒙特卡罗模拟程序MCNP (Monte Carlo N Particle Transport Code)计算了一台10.16 cm×10.16 cm×40.64 cm NaI(Tl)探测器的能量响应矩阵,采用极大似然法和该能量响应矩阵对包含10种不同能量特征峰的MCNP模拟能谱、铅屏蔽室和实验室自然环境中测得的152Eu点源的γ能谱进行反演。结果显示:对模拟的γ能谱,反演后特征峰中心道址相对参考值最大偏差为1道;对铅屏蔽室中的152Euγ能谱,反演后特征峰中心道址与实测值偏差小于2道;对实验室自然环境中152Euγ能谱,反演后特征峰中心道址与实测值偏差小于4道。[Background] The inversion of gamma spectrum by maximum likelihood method can effectively improve the energy resolution of gamma spectrum.[Purpose] This study aims to observe the ability of maximum likelihood method to retrieve the central channel of γ characteristic peaks.[Methods] Monte Carlo simulation program MCNP (Monte Carlo N Particle Transport Code) was used to calculate the energy response matrix of a 10.16 cm×10.16 cm×40.64 cm NaI(Tl) detector. Energy response matrix, the simulated spectra contained 10 different peaks, and the 152Eu γ spectra obtained by the experiment were retrieved.[Results & Conclusions] The results showed that the maximum deviation of the peak center channel between the retrieved spectra and the simulated spectra was 1 channel, deviation between the retrieved spectrum and 152Eu γ spectrum measured in the lead shielding room was less than 2 channels, the deviation between the retrieved spectrum and 152Eu γ spectrum measured in the laboratory's natural environment was less than 4 channels.

关 键 词：极大似然法 Γ能谱 反演 峰中心 

分 类 号：TL81[核科学技术—核技术及应用]