基于Geant4的慢正电子束注入金属材料的模拟研究

Simulation of the implantation of slow positron beams into metallic materials based on Geant4

用Geant4软件对慢正电子束注入金属材料的过程进行了模拟,模拟计算了正电子垂直入射与倾斜入射金属材料的背散射系数,得到了倾斜入射条件下正电子深度分布曲线及入射倾角与正电子背散射系数的关系曲线,同时进一步分析了不同入射倾角条件下正电子在材料中的横向扩散行为,模拟结果表明金属材料原子序数越小,慢正电子束倾斜入射样品后其横向扩散越显著.该模拟研究为慢正电子束对金属材料的实验和理论研究提供了参考数据.

The processes of slow positron beam implantation into metals were studied by employing the Geant4 software.The backscattering coefficients of two patterns(i.e.normal incidence and oblique incidence)were calculated,and the distribution curves of positron implantation depth at oblique incidence and the relations between the backscattering coefficient and the incident angle were obtained.Further analysis of lateral diffusions of positrons at different angles was conducted.Simulations indicate that the lateral diffusions of slow positrons become more significant obliquely implanting into metals with smaller atomic numbers.The simulation can provide some useful referential data for the research of metals using slow positron beam technology.