低地球轨道（LEO）的大型航天器充电

CHARGING OF LARGE SPACECRAFT IN LEO

本文根据ＬＥＯ中等离子体温度低、密度高、德拜长度小的特点，采用薄鞘层近似，计算了离子收集电流；根据电流平衡方程，考虑表面二次电子发射，计算了大型航天器表面在沉降电子流辐照下的充电特性。结果表明，较大的沉降电子电流会使航天器表面达到很高的负电位，而且随着航天器尺度的增大，充电电位也相应地增高。

On the basis of the plasma conditions in LEO. We adopt plasma thin sheath model and calculate ion collection current.By solving local current balance equation including secondary electron emission of spacecraft surface. We computer the charging characteristics of large spacecraft by the energetic precipitating electron beam. The results indicate that precipitating electrons can induce large negative voltage.The larger the spacecraft's size. the higher voltage the charging potential.