地球同步轨道航天器在地磁亚暴环境下处于向光面和背光面的两侧会产生电位差。本文利用高能电子和高能离子的双麦克斯韦分布拟合同步轨道环境等离子体并加入二次电子和光电子的影响,建立了航天器的三维计算模型,利用基于PIC(Particle In Cell)方法的仿真程序,计算了航天器表面各材料的充电电位及其附近的等离子体的电位分布,以及低能电子、高能电子、二次电子和光电子的密度分布和充电电流分布,最后探讨了航天器不同表面材料电势随时间的变化情况。
In order to further understand the characteristics of the floating potential of low earth orbit spacecraft,the effects of the electron current collection area,background electron temperature,photocurrent emission,spacecraft wake,and the shape of spacecraft on spacecraft floating potential were studied here by particle-in-cell simulation in the low earth orbit.The simulation results show that the electron current collection area and background electron temperature impact on the floating potential by changing the electron current collection of spacecraft.By increasing the electron current collection area or background electron temperature,the spacecraft will float at a lower electric potential with respect to the surrounding plasma.However,the spacecraft wake affects the floating potential by increasing the ion current collected by spacecraft.The emission of the photocurrent from the spacecraft surface,which compensates for the electrons collected from background plasma,causes the floating potential to increase.The shape of the spacecraft is also an important factor influencing the floating potential.
