球型高压电离室壁厚对光子能量响应的蒙特卡罗优化设计

Monte Carlo Method based Optimal Design of Wall Thickness Response of Spherical Ionization Chamber to Photon Energy

采用EGS5蒙特卡罗程序模拟计算了一种球型高压电离室的室壁厚度。计算给出了多种不同室壁厚度下,单位光子注量沉积在球型高压电离室氩气中的能量;分析归纳出用于计算球型高压电离室对特定范围内室壁厚度和光子能量的响应因子的公式;依据国家相关检定规范和归纳公式,给出了球型高压电离室的最佳室壁厚度。

In this study,we use Fluka Monte Carlo code to optimize the wall thickness of a spherical ionization chamber.The energy deposited in the argon gas per photon for photon energy from 48 keV to 3 MeV,and corresponding wall thickness,d,for 1.0 mm≤d≤4.0 mm were given respectively.Our result of Monte Carlo simulation was used to present the formulae for calculate the normalized energy response.The optimal wall thickness of the spherical ionization chamber was recommended according to the verification regulations.