3次元プラズマ粒子シミュレーションによる極軌道衛星の帯電解析とその緩和手法の検討

摘要

In the present paper, we focus on the mitigation process of differential charging of spacecraft in the polar environment byplasma release from the spacecraft surface. In the presence of aurora electron beam, the absolute charging of spacecraftsometimes becomes the order of KeV and the differential charging between the conducting surface of the spacecraft andthe dielectric material on the solar panel can become several hundreds volts. To avoid the discharge due to thedifferential charging at the solar panel, plasma release from a plasma contactor onboard the spacecraft is proposed as oneof the effective methods. In the current study, we performed three-dimensional Particle-In-Cell simulations to examinethe situation of spacecraft charging and plasma release from the spacecraft surface for the charging mitigation. Weparticularly examined the transient process in terms of electron/ion flux to the spacecraft surface and the correspondingpotential variation in the charge mitigation process in cases where thermal electrons or beam electrons are emitted.