空间材料二次电子发射过程的理论研究

STUDY OF SECONDARY ELECTRON EMISSION OF SPACE MATERIALS

航天器充放电效应故障大多都会引起卫星灾难性事故,对航天器在轨安全运行产生较大的影响。空间材料的二次电子发射系数是决定卫星表面带电速率和充电平衡电位水平的重要材料特征参数,对于卫星表面带电的预测及卫星带电设计选材具有重要的意义。基于蒙特卡洛方法,从理论上分析了材料二次电子的产生、转移及逃逸过程,获得了材料二次电子发射系数的计算方法。实验结果表明该方法能较好地拟合材料二次电子发射系数随入射电子能量的变化趋势,为航天器充放电效应数值模拟和防护设计提供数据支持。

Spacecraft charging due to irradiation by radioactive rays and plasma environment can cause serious problems to the safety and reliability of spacecraft on the orbit. The secondary electron emission （ SEE ）yield of space materials is one of important parameters relative to the spacecraft surface charging level, it is also important for prediction of satellite surface charging and selection of surface materials in the design against spacecraft charging. Based on Monte Carlos simulation method, this paper investigates the theoretical process of generation, transfer and escape of secondary electrons as a function of the surface potential of the spacecraft, and finally the paper present a mathematical model to calculate the secondary electron emission yield. The results indicate that this calculation method can preferably fit the trend of secondary electron emission yield varies with primary electron energy, and the work can provide the perspective of the spacecraft charging problem.