【作者】 张佳媚； 倪建忠； 何小兵； 凡金龙；

【Author】 ZHANG Jia-mei,NI Jian-zhong,HE Xiao-bing,FAN Jin-long (Northwest Institute of Nuclear Technology,Xi’an.710024,China)

【机构】 西北核技术研究所；

【摘要】 描述了一种对含多种低比活度人工放射性核素的质量为1 g左右的粉末样品进行γ无损分析的方法。样品装在特制的塑料盒中,形成φ26 mm×3 mm的小圆盘状,在距HPGe探测器1 cm的位置测量。主要解决了多种核素的全能峰绝对效率准确标定问题,包括自吸收校正。用多种放射性核素溶液制成的相同源盒的平面源,经过多个位置多个测量步骤,计算得到小圆盘测量样品的峰效率。对测量结果分析讨论,这种无损分析方法的相对不确定度为2%～4%。经与部分样品其中两种核素的放化分析结果比对,验证了两者的一致性。更多还原

【Abstract】 A nondestructive method for determination of several low-level activity radionuclides in samples of one gram powder by gamma-ray spectrometry is described.Each sample is loaded by a custom-made plastic box,forming a small disk ofφ26mm×3mm.Sample box are measured in a lower position,about 1cm far from the HPGe detector.The main problem of calibration of absolute full-energy peak efficiencies for those nuclides has been resolved,including self-absorption correction. Planar sources using same boxes are prepared with radionuclides solution to measure on several different positions in order to calculate the efficiencies of disk samples.The relative uncertainties of radioactivity by this method are between 2%to 4%by discussing measurement results and confirmed by radiochemical analyses of two nuclides with partial samples.更多还原