【摘要】 采用源对探测器窗口的投影重叠面积法计算了特定条件下的几何因子,并对其进行了实验验证。实验验证部分是利用日本原子力研究所大洗研究所的设备,在日本STA资助的科技交流计划中完成的。探测器为半导体探测器,其面积为450mm²。放射源为²⁴¹Am,²³⁸U,²³³U,²³⁹Pu和²⁴⁴Cmα标准源,此外,在真空室内的样品盘和探测器之间的距离是精确可调的。当对源和探测器之间距离的读数值重新刻度和对²⁴¹Am源重新校正,并对多道的ADC零点修正后,计算的几何因子与实验测得的探测效率的相对误差对薄源在6％以内。此外,为了验证α粒子受射程限制时的几何因子,用2000mm²的探测器,在不对样品室抽真空的条件下做了验证实验。结果表明:当作了甄别阈和窗口厚度修正以后,理论和实验值符合很好,其相关系数近似为0.9999,经X²检验和F检验亦未见显著性差异。更多还原

【Abstract】 The calculation of geometry factors under special conditions through a method based on the overlapping area of the source and the projection of the detector and experimental verification are introduced. The experimental verification was done in Oarai Institute of Japan Atomic Energy Institute under Japan STA Scientist Exchange Program. The sample chamber can be pumpped and the distance between sample disk and detector is accurately adjustable. Semiconductor detector with the area of 450 mm2 and alpha standard sources 241Am,238U,233U,239Pu and 244Cm were used for experiment. After the recalibration for the indication and actual separation between sample disk and detector, the activity of 241Am source and the ADC zero point of multichannel, calculation values conform with experiment within 6%. When sample chamber is not vacuum , the experimental verification of geometry factors affected by alpha range is done with 2000 mm2 detector, and the theoretical values meet the experimental values very well after the revision of discriminating threshold and the thickness of detector windows. The relative coefficient is about 0. 9999 and there aren’t significant differences after X2 and F check.更多还原