航空γ能谱全谱数据的高斯分解方法
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摘要
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NaI(Tl)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合方法研究。对铀源、钍源和铯源实验数据用单高斯拟合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合方法仍需进一步深入研究。
The radioactive concentrations of 137Cs source and other man-made radionuclides are important data for estimating environment radiation level in nuclear emergence. In order to extract the data of energy peak of 137Cs from full spectra measured by NaI(Tl) 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 relative 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.
The radioactive concentrations of 137Cs source and other man-made radionuclides are important data for estimating environment radiation level in nuclear emergence. In order to extract the data of energy peak of 137Cs from full spectra measured by NaI(Tl) 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 relative 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.
引文
[1]IAEA.Airborne gamma ray spectrometer surveying,IAEA Technical Reports[R].Vienna:Austria,1991(323).
[2]ICRU.International Commission on Radi-ological Units and Measurements,ICRU report53[R].Bethesda,Maryland:U.S.A.
[3]SANDERSON D C,CRESSWELL A J,et al.An airborne gamma-ray spectrometry survey of nuclear sites in Belgium[J].Journal of Environmental Radioactivity,2004,72(1-2):213-224.
[4]GUILLOT L.Extraction of full abstraction peaks in airborne gamma-spectrometry by filtering techniques coupled with a study of the derivatives Comparison with the window method[J].Journal of Environ-mental Radioactivity,2001,53(3):381-398.
[5]ALLYSON J D,SANDERSON D C W.Monte carlo simulation of environmental airborne gamma-spectrometry[J].Journal of Environmental Radioactivity,1998,38(3):259-282.
[6]王南萍,熊盛青,周锡华,等.航空伽玛能谱仪对137Cs点源响应特征及全谱数据的提取技术[J].核技术,2005,28(4):313-318.
[7]中国地球物理学会.中国地球物理学会年刊2002[C].北京:地震出版社,2002:190.
[8]DUBOIS G,DE CORT M.Mapping137Cs deposition:data validation methods and data interpretation[J].Journal of Environmental Radioactivity,2001,53(3):271-289.
[2]ICRU.International Commission on Radi-ological Units and Measurements,ICRU report53[R].Bethesda,Maryland:U.S.A.
[3]SANDERSON D C,CRESSWELL A J,et al.An airborne gamma-ray spectrometry survey of nuclear sites in Belgium[J].Journal of Environmental Radioactivity,2004,72(1-2):213-224.
[4]GUILLOT L.Extraction of full abstraction peaks in airborne gamma-spectrometry by filtering techniques coupled with a study of the derivatives Comparison with the window method[J].Journal of Environ-mental Radioactivity,2001,53(3):381-398.
[5]ALLYSON J D,SANDERSON D C W.Monte carlo simulation of environmental airborne gamma-spectrometry[J].Journal of Environmental Radioactivity,1998,38(3):259-282.
[6]王南萍,熊盛青,周锡华,等.航空伽玛能谱仪对137Cs点源响应特征及全谱数据的提取技术[J].核技术,2005,28(4):313-318.
[7]中国地球物理学会.中国地球物理学会年刊2002[C].北京:地震出版社,2002:190.
[8]DUBOIS G,DE CORT M.Mapping137Cs deposition:data validation methods and data interpretation[J].Journal of Environmental Radioactivity,2001,53(3):271-289.
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