g因子的蒙特卡罗模拟计算

在电离辐射空气比释动能基准量值复现过程中, g因子作为关键组成部分之一,参与量值复现和不确定度计算,其量值的确定需要通过光子的质能传输系数和质能吸收系数计算得到。采用不同的软件,在不同参数设置条件下模拟计算并对结果进行比较。结果显示采用EGSnrc计算结果更为合理,而且对于低能光子来说,尽管g因子相对较小,但在不同的参数设置条件下所得到的数值差异较大。因此在涉及到低能光子的质能传输系数和质能吸收系数的计算和使用过程中,需对有关的相互作用的物理机制予以重视。

Monte Carlo Simulation Method for g Factor

In the process of establishing the primary standards of air kerma, the g factor is one of the key components,which is involved in the value recurrence and uncertainty calculation, and the calculation of g factor required the mass energy transfer coefficient and mass energy absorption of the photon. The results were got and compared by using different software to simulate with different parameter settings. The results show that the calculation results from EGSnrc are more reasonable, especially for low-energy photons, although the g factor is relatively small. The values obtained under different parameter setting conditions are quite different. Therefore, attention should be paid to the physical mechanism of the relevant interactions in the process of the calculation and the use of the mass-energy transmission coefficient and the mass-energy absorption coefficient for low-energy photons.