基于Geant4的α粒子能谱模拟研究及软件设计实现

Research and software design ofαparticle energy spectrumsimulation based on Geant4

为进一步发展基于蒙特卡罗模拟方法的α粒子能谱探测参数优化技术,利用PyQt5设计一款调用蒙特卡罗模拟程序包Geant4进行α粒子能谱模拟研究的软件。一方面,建立了测量α粒子的钝化离子注入平面硅探测器(Passivated Implanted Planar Silicon)物理模型,根据实际α粒子测量条件对模拟的物理过程、模型材料及粒子源几何形状、成分等参数进行校正,结合PyQt5界面开发平台将粒子源参数、探测器参数修改等功能可视化。在多个探源距和不同真空压强条件下进行模拟实验,得到该模型的探测效率,并将获取的能量沉积成谱后,通过EMG-Landau响应函数模型展宽。另一方面,为验证该探测器模型的准确性,将模拟结果与实测结果的探测效率进行对比,实验结果表明,两者探测效率误差均在5%之内,且EMG-Landau响应函数模型展宽效果良好。本文研究结果验证了该Geant4模拟软件在α粒子能谱研究方面的可靠性,该软件可直观修改α粒子能谱测量条件,简化了模拟步骤,提高了模拟效率,为基于蒙特卡罗模拟方法的α粒子能谱探测参数优化技术提供了有力工具。

To further develop the optimization technology of alpha particle energy spectrum detectionparameters based on Monte Carlo simulation method,this paper uses PyQt5 to design a software that calls MonteCarlo simulation package Geant4 for alpha particle energy spectrum simulation research.On the one hand,a physicalmodel of the Passivated Implanted Planar Silicon detector for measuringαparticles is established,and the simulatedphysical process,model materials,particle source geometry,composition and other parameters are corrected accordingto the actualαparticle measurement conditions,combined with the PyQt5 interface.The development platformvisualizes functions such as particle source parameters and detector parameter modification.The detection efficiencyof the model is obtained by performing simulation experiments under multiple detection distances and differentvacuum pressure conditions,and after the acquired energy is deposited into a spectrum,it is broadened by the EMG-Landau(Exponentially Modified Gaussian and Landau)response function model.On the other hand,to verify theaccuracy of the detector model,the detection efficiency of the simulation results and the measured results arecompared.The experimental results show that the detection efficiency errors of both are within 5%,and the EMG-Landau response function model broadened works well.The research results of this paper verify the reliability of theGeant4 simulation software in the study ofα-particle energy spectrum.The software can directly modify themeasurement conditions ofα-particle energy spectrum,simplify the simulation steps,and improve the simulationefficiency,thus provides a powerful tool forα-particle energy spectrum detection parameter optimization technology.