^137Cs等人工放射性核素的活度浓度是核应急环境电离辐射水平评价中的重要数据。为了提取Nal(TI)航空γ能谱仪(GR-820)实测全谱数据的^137Cs信息,采用高斯最小二乘拟合算法对实验谱线的低能重叠峰进行了单高斯和双高斯峰的拟台方法研究。对铀源、钍源和铯源实验数据用单高斯拟台的最大相对误差小于±15%,对铀和铯混合源的双高斯峰拟合峰面积的平均误差为21.84%。对3个重叠峰以上的高斯拟台方法仍需进一步深入研究。
The radioactive concentrations of ^137Cs source and other man-made radionuelides are important data ibr estimating environment radiation level in nuclear emergence. In order to extract the data of energy peak of ^137Cs from lull spectra measured by NaI (TI) airborne gamma-ray spectrometer (GR-820), the overlapped peaks at lower energy bands are deconvolved by Gauss function fitting by least square (single peak and double peaks). The maximum relative error of single peak area is less than ±15% due to only uranium, thorium or cesium sources. And the average rclative error of overlapping peak (double peaks) is 21.84%, which are produced by uranium and cesium sources, A research of deconvolving overlapped peaks of more than three peaks is needed.