长方体废物箱测量中探测效率刻度的抽样算法

The Sampling Algorithm of the Detection Efficiency Calibration for the Measurement of Rectangular Waste Container

建立了一种蒙特卡罗积分算法和以BECK公式为基础的数值计算方法相结合的抽样算法,该算法用于长方体废物箱测量中探测效率的刻度。该算法用实验测得的探测器角响应函数和有效前面积作为探测器的响应参数,用线衰减系数表征γ射线穿透介质的衰减属性,并根据BECK公式建立被积函数的表达式。在样品的几何空间内均匀抽样,并计算得到射线的衰减路径后,用蒙特卡罗积分算法计算得到探测器对长方体废物箱的活度浓度转换系数。在相同测量条件下,使用本抽样算法和基于BECK公式的数值计算方法分别计算了探测器对样品的活度浓度转换系数。结果表明,两种方法在±2.01%的相对误差范围内相符,说明所建立的抽样算法是正确的。该算法原理简单、计算速度快,且能够被用于复杂几何情况下探测效率的计算。

It presented a sampling algorithm for the efficiency calibration of rectangular waste container which was combined with the integral method using Monte Carlo and one numeric method based on the Beck formula. The angular response function and effective frontier area（EFA）were seen as the response parameters of detector, and the linear attenuation coeffients（μ）was used to characterize the attenuation attributes that the gamma ray penetrated from the substances between sample and detector.And the expression of integrated funtion was gained which is based on the BECK formula.After the uniform sampling was completed in the geometrical space of sample and the attenuation paths of gamma-ray were calculated,the Monte Carlo integral method was utilized to calculate the activity concentration transform coefficients of detector for the rectangular waste container. Under the same measurement conditions,the activity concentration transform coefficients of detector for the sample have been calculated with sampling algorithm and numerical calculation method based on the BECK formula. The results indicated that both methods was in agreement in the range of 2.01%for the relative deviation error,it proved that the algorthm built is accurate.The algorithm whose principle is simple,that its computation velocity is quick,which can be used to calculate the detection efficiency in the case of complicated geometrical structure.