Levenberg-Marquardt高斯拟合法在NaI(Tl)γ谱分析中的应用  

The Application of the Levenberg-Marquardt Gaussian Fitting Method in NaI(Tl) γ Spectrum Analysis

作　　者：杨志辉[1] 李跃忠[1] 余倩[1] 瞿诗涛[1] 

机构地区：[1]东华理工大学机械与电子工程学院,江西南昌330013

出　　处：《核电子学与探测技术》2013年第10期1271-1273,1277,共4页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金项目(61064013);核技术应用教育部工程研究中心开放基金项目(HJSJYB2010-10)

摘　　要：为提高γ谱法测定核素活度的准确性,采用高斯函数对除本底后的峰区进行峰形拟合,并根据Levenberg-Marquardt法对拟合方程进行求解得出峰形参数。该方法是以预处理所得峰高、峰位和峰宽为初值,并自适应计算步长进行迭代直至迭代完毕。根据计算仿真结果分析,该方法能够将单能峰拟合到最佳状态,且能将重叠峰分离成多干单峰并拟合。实验表明,该方法可快速准确地计算特征峰峰面积,所得核素特征峰面积与HPGe谱仪所测峰面积相对误差小于8%。In gamma spectroscopy analysis, in order to improve the accuracy of the radionuclide activity, the net count of the radionuclide characteristic peaks is particularly important. The paper adopted the Gaussian function fitting the peak shape of the peak area after subtracting the background of the peak area, and the paper gets the peak shape parameters by solving the fitting equation according to the Levenberg - Marquardt method, this method takes the pretreatment resultant peak height, peak position and peak width as the initial value, and adap- tive computes step size to iterate until the iteration is completed. Analyzing according to the computational sim- ulation results, this method can fit mono - energetic peak to the best state, and the overlapped peaks can be separated into multiple single peak then do fitting. Through the experiment, the relative error between the above method measured nuclides characteristic peak area and the HPGe spectrometer measured peak area is less than 8 %, the experimental results show that this method can rapidly and accurately calculate the characteristic peak area,

关 键 词：Levenberg—Marquardt 高斯拟合法 特征峰 

分 类 号：TL817.2[核科学技术—核技术及应用]