Monte Carlo simulation of exposure factor

In this paper, we simulate the exposure factor by a simple model of a free-air ionization chamber with the Monte Carlo programme Geant4. Special emphasis is placed on the discussion of the exposure factor related to parameters of the chamber model. The reason for the variation in exposure factor with incident ray energy is also analysed in terms of reaction cross section for different types of reactions. The obtained results indicate that our simulation is accurate in the calculation of the exposure factor and can serve as a reference in designing air ionization chambers.     

康普顿效应散射装置简介

本文从X射线研究的发展史出发,简述了康普顿效应原理．分别以分光技术和多道能谱技术,分析了X射线、γ射线散射装置的结构及实现原理．文章最后总结了康普顿效应的物理意义,同时指出了反康普顿效应在能谱仪研制中的重要性．