高能γ探测系统中的光耦合部件参数优化

建立了Geant4软件粒子输运模拟平台，完成了核聚变高能射线能量-时间联合谱探测系统的探测效率计算数值建模；提出了遗传算法调用Geant4软件的射线探测系统参数优化方法。以自聚焦透镜前端与塑料闪烁体后端面的距离、自聚焦透镜后端面的长度及自聚焦透镜与通信光纤前端的距离为自变量，以耦合效率为适应度函数，实现了高能探测系统中由塑料闪烁体-自聚焦透镜-通信光纤组成的光耦合部件参数的优化算法。优化结果表明，该算法可以提高塑料闪烁体发出的荧光由自聚焦透镜耦合到通信光纤中的效率，最大可达4.77%。

Optical coupling structure parameter optimization for high energy gamma-ray detection system

Geant4 software can not only simulate the interaction processes of rays and material but also the following transportation of optical photons produced by these processes. In this study, the Geant4 particle transport simulation platform was established. The optical coupling efficiency calculation model of the nuclear fusion γ-ray energy-time joint spectrum detection system was constructed. The optimization method employing the genetic algorithm to call Geant4 code was proposed. The parameters of optical coupling structure were optimized by the genetic algorithm using the gap length in the front of the grid lens, the length of the grin lens, and the gap length at the rear of the grin lens as the independent variables and using the coupling efficiency as the fitness function. Optimization results show that the coupling efficiency between the scintillator and optical fiber could be improved with this method, which is about 4.77%.