Si(Li)探测器低能区的效率刻度

通过测量19keV电子束轰击厚碳靶产生的韧致辐射能谱，在低能区（>1keV）对Si(Li)探测器进行了探测效率刻度。厚碳靶的理论韧致辐射能谱由Monte-Carlo程序PENELOPE计算，并用²⁴¹Am标准放射源确定出效率刻度曲线的绝对值。采用本工作的刻度方法确定的效率刻度曲线误差主要来源于用标准放射源绝对化的误差，约为5%。将所得初步实验结果与理论计算值进行了比较，并采用最小二乘法对探测器各厚度参数进行了拟合，除Au接触层厚度外，拟合的各厚度值与探测器生产商提供的数据较为吻合。

Efficiency Calibration of Si(Li) Detector in Low-Energy Region

The detection efficiency calibration of Si(Li) detector in low-energy region down to 1 keV was carried out by measuring the bremsstrahlung spectrum of thick-carbon-target bombarded by 19 keV electron beam.The coupled electron-photon transport Monte-Carlo computer code PENELOPE was employed for theoretical calculation of thick-carbon-target bremsstrahlung spectrum.The absolute value of the efficiency calibration was determined from the use of ~(241)Am radioactive standard source.The uncertainty for the efficiency calibration with present method is mainly stemmed from the use of ~(241)Am radioactive standard source and it was estimated to be about 5%.The preliminary experimental efficiency calibration values were also compared with calculation values based on a simple model.The detector thickness parameters were also determined by a nonlinear least-squares fit.Except the Au-contact layer,the other thickness parameters are in acceptable agreement with that provided by detector manufacturer.