Asymmetric electrostatic environment around spacecraft in weakly streaming plasmas
Asymmetric electrostatic environment around spacecraft in weakly streaming plasmas
复制标题
弱流等离子体中航天器周围的不对称静电环境
DOI：
10.1002/2015ja021064
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Y. Kasaba
中科院分区：
文献类型：
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作者：
Y. Miyake;Y. Nishimura;Y. Kasaba
在漂移等离子体中进行的双探针电场测量会受到科学航天器附近不对称静电结构所导致的虚假效应影响。在等离子体层外侧的一些原位观测发现，即使在跨磁力线的亚声速离子流中，由于这种环境不对称也会检测到虚假电场。我们进行了三维粒子模拟，该模拟能够包含又长又极细的丝状伸展结构以及航天器底盘，并对能解释观测结果的静电环境进行了研究。目前的模拟显示，即使是亚声速离子流也能在航天器的上游和下游侧之间产生明显的电势差，并且该电势差会被检测为几毫伏/米的虚假电场。产生虚假电场的必要条件是航天器具有相对较高（几十伏）的电势，并且航天器电势凸起需要通过偏置在航天器电势的细丝状伸展结构来扩展。分析还表明，重离子流和沿场方向的离子上升流的存在可将虚假电场进一步增强至5毫伏/米。
The double‐probe electric field measurements in drifting plasmas are subject to spurious effects caused by asymmetric electrostatic structure near scientific spacecraft. Some in situ observations just outside the plasmasphere detected spurious electric fields due to such environmental asymmetry even in subsonic ion flows across the magnetic field line. We have performed three‐dimensional particle‐in‐cell simulations, which allow us to include long and extremely thin wire booms as well as a spacecraft chassis, and investigated an electrostatic environment that accounts for the observations. The present simulations reveal that even subsonic ion flows can produce an appreciable potential difference between the upstream and downstream sides of the spacecraft, and the potential difference would be detected as a spurious field of a few mV/m. The necessary condition for the spurious field is a relatively high (a few tens of V) spacecraft potential, and also the spacecraft potential hump needs to be expanded by thin wire booms biased at the spacecraft potential. The analysis also reveals that the presence of a heavy ion flow and a field‐aligned ion upflow can further enhance the spurious field up to 5 mV/m.
航天器-等离子体相互作用
DOI：
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发表时间：
2009
期刊：
影响因子：
--
作者：
原良太郎;野澤あい;木野邦器;岡佑一;臼井英之
通讯作者：
臼井英之