Extraction of full energy peak of Cs-137 from in situ NaI (Tl) gamma-ray spectrum
Extraction of full energy peak of Cs-137 from in situ NaI (Tl) gamma-ray spectrum
复制标题
从原位 NaI (Tl) 伽马射线谱中提取 Cs-137 的全能峰
DOI：
10.1007/s41365-016-0090-x
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发表时间：
2016
影响因子：
2.8
通讯作者：
Li Bao-Chuan
中科院分区：
文献类型：
--
作者：
Zhang Le-Le;Wang Nan-Ping;Li Bao-Chuan
用Levenberg-Marquardt高斯拟合算法分析了NaI（Tl）闪烁谱仪上208 Tl的583 keV峰、214 Bi的609 keV峰和137 Cs的662 keV峰的重叠。此外，该算法与用于多次反褶积的遗传算法进行了比较。三个拟合峰面积（583，609，和662 keV）计算从模拟实验中，a137 Cs源埋在不同的土壤深度（从18至38厘米）获得的测量γ射线光谱。Levenberg-Marquardt算法的应用产生了类似的结果相比，遗传算法。一个缺乏的拟合检验表明，拟合是好的，当仪器噪声水平估计从重复分析。总净面积的相对拟合误差和残差标准差分别在5%和0. 04以内，拟合优度优于0. 98。虽然本文中使用的方法提供了高性能，但当信噪比小于−30 dB时，结果可能导致不正确的估计。本研究为现场能谱法测定~（137）Cs的放射性比活度提供了依据。
A Levenberg–Marquardt Gaussian fitting algorithm has been used for analyzing the overlap of three peaks (the 583-keV peak of208Tl, the 609-keV peak of214Bi, and the 662-keV peak of137Cs) using an in situ NaI (Tl) scintillation spectrometer. The algorithm, in addition, was compared with a genetic algorithm used for multiple deconvolution. The three fitted peak areas (583, 609, and 662 keV) were calculated from the measured gamma-ray spectra obtained from a simulation experiment in which a137Cs source was buried at different soil depths (from 18 to 38 cm). The application of the Levenberg–Marquardt algorithm yielded similar results compared to the genetic algorithm. A lack-of-fit test showed that the fitting is good when the instrumental noise levels were estimated from replicated analyses. The relative fitting error of the total net area and the residual standard deviation were within 5 % and 0.04, respectively, and the goodness of the fitting was better than 0.98. While the methods used in this paper give high performance, the results may lead to incorrect estimation when the signal-to-noise ratio is smaller than −30 dB. This study is useful for the determination of radioactive specific activity of137Cs by in situ spectrometry.