屏栅电离室是一种测量带电粒子的常用探测器。本工作利用蒙特卡罗模拟计算方法,理论计算不同能量的α粒子在电离室不同填充气体条件下的能损分布及电子-离子对数,优化选择合适的填充气体。计算不同能量α粒子在电离室填充气体中的最大射程,确定电离室阴极与阳极的合适距离,为优化设计电离室结构、设定合适的充气种类和工作气体压力提供理论计算依据。计算3种能量的α粒子在不同电离室填充气体的最大射程和电子离子对数,结果列于表1,分析可得,α粒子在不同电 Screen ionization chamber is a commonly used detector to measure charged particles. In this work, Monte Carlo simulation method was used to calculate the energy loss and electron-ion logarithm of different energy α particles under different filling gas conditions in the ionization chamber to optimize the selection of appropriate filling gas. Calculate the maximum range of different energy α particles in the ionization chamber filling gas to determine the appropriate distance between the cathode and the anode of the ionization chamber to provide the theoretical basis for optimizing the design of the ionization chamber structure, setting appropriate types of aeration and working gas pressure. Calculate the energy of the three kinds of α particles in different ionization chamber filled with the maximum range of gas and electron ion pairs, the results are shown in Table 1, we can see that α particles in different electricity