蒙特卡罗模拟-高斯重建相结合解析γ能谱
Analysis of the Gamma spectrum using Monte Carlo simulation and Gaussian reconstruction
叶二雷 1陈菲 2来永芳 1刘婧源3
作者信息
- 1. 陆军防化学院 核防护系, 北京 102205
- 2. 96765 部队,山西 长治 046000
- 3. 93671 部队,河南 南阳 474350
- 折叠
摘要
为了解决常规γ能谱解析中康普顿坪影响较大、峰面积计算不准确的问题,提高γ核素活度测量结果的准确度,本文基于蒙特卡洛方法建立了NaI(Tl)探测器物理模型,同时针对模拟谱与实测谱在康普顿坪区的差异,根据γ谱形成机理,提出比值法以修正模拟谱,并生成标准γ核素谱.再以标准γ能谱为基础,通过从高能到低能的顺序进行剥谱和确定全能峰区,以解析137 Cs和60 Co相叠加的γ实测谱,所得活度测量结果的相对误差在±3.5%以内,明显优于常规解谱方法.结果表明:采用蒙特卡罗模拟标准谱与实测谱特征峰高斯重建相结合而解析γ能谱,既能大幅降低实测谱中康普顿坪对较低能量γ射线特征峰的影响,也能较准确地确定特征峰面积,为γ能谱分析提供了一种能显著提高γ核素活度测量准确度的方法.
Abstract
In this study,to solve the problem of the large influence of the Compton plateau and inaccurate calcula-tion of the peak area in conventional γ spectrum analysis and improve the accuracy of γ nuclide activity measure-ment,a physical model of NaI(Tl)detector was established using the Monte Carlo(MC)method.Considering the difference between the simulated and measured spectra at the Compton plateau,the ratio method was established to modify the simulated spectrum according to the formation mechanism of γ spectrum,thereby generating a standard γ nuclide spectrum.Based on the standard γ spectrum,the spectrum was stripped from high to low energy,and the all-around peak regions were determined.Additionally,the measured γ spectrum of 137 Cs and 60 Co phase superpo-sition was analyzed.The result reveals that the relative error of 137 Cs and 60 Co activities is less than 3.5%,which is obviously better than conventional spectral-solving methods.This also indicates that combining the MC simulated standard spectrum and Gaussian reconstruction of the characteristic peak of the measured spectrum can significantly reduce the influence of Compton plateau to low energy γ-ray characteristic peak and accurately determine the area of the characteristic peak.Moreover,this study provides a promising method for γ spectrum analysis,which can significantly improve the accuracy of γ nuclide activity measurements.
关键词
γ能谱/蒙特卡罗模拟/准确度/高斯重建/康普顿坪/峰面积/修正/活度测量Key words
gamma spectrum/Monte Carlo simulation/accuracy/Gaussian reconstruction/Compton plateau/peak area/amendment/activity measurement引用本文复制引用
出版年
2023
国家科技期刊平台
NSTL
维普
万方数据