Active spacecraft potential control for Cluster - implementation and first results

	Active spacecraft potential control for Cluster - implementation and first results
	Torkar, K. ; Riedler, W. ; Escoubet, C. P. ; Fehringer, M. ; Schmidt, R. ; Grard, R. J. L. ; Arends, H. ; Rudenauer, F. ; Steiger, W. ; Narheim, B. T. ; Svenes, K. ; Torbert, R. ; Andre, M. ; Fazakerley, A. ; Goldstein, R. ; Olsen, R. C. ; Pedersen, A. ; Whipple, E. ; Zhao, H.
刊名	Annales Geophysicae
	2001
卷号	19 期号:40463 页码:1289-1302
关键词	space plasma physics spacecraft sheaths instruments and techniques active perturbation experiments metal ion-source photoelectron sheath electric-field magnetosphere photoemission mission wakes charging
ISSN号	0992-7689
通讯作者	北京8701信箱
英文摘要	Electrostatic charging of a spacecraft modifies the distribution of electrons and ions before the particles enter the sensors mounted on the spacecraft body. The floating potential of magnetospheric satellites in sunlight very often reaches several tens of volts, making measurements of the cold (several eV) component of the ambient ions impossible. The plasma electron data become contaminated by large fluxes of photoelectrons attracted back into the sensors. The Cluster spacecraft are equipped with emitters of the liquid metal ion source type, producing indium ions at 5 to 9 keV energy at currents of some tens of microampere. This current shifts the equilibrium potential of the spacecraft to moderately positive values, The design and principles of the operation of the instrument for active spacecraft potential control (ASPOC) are presented in detail. Experience with spacecraft potential control from the commissioning phase and the first two months of the operational phase are now available. The instrument is operated with constant ion current for most of the time, but tests have been carried out with varying currents and a "feedback" mode with the instrument EFW which measures the spacecraft potential. That has been reduced to values according to expectations. In addition, the low energy electron measurements show substantially reduced fluxes of photoelectrons as expected. The flux decrease in photoelectrons returning to the spacecraft, however, occurs at the expense of an enlarged sheath around the spacecraft which causes problems for boom-mounted probes.
收录类别	SCI
原文出处	://000173873200009
语种	英语
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/1553]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Torkar, K.,Riedler, W.,Escoubet, C. P.,et al. Active spacecraft potential control for Cluster - implementation and first results[J]. Annales Geophysicae,2001,19(40463):1289-1302.
APA	Torkar, K..,Riedler, W..,Escoubet, C. P..,Fehringer, M..,Schmidt, R..,...&Zhao, H..(2001).Active spacecraft potential control for Cluster - implementation and first results.Annales Geophysicae,19(40463),1289-1302.
MLA	Torkar, K.,et al."Active spacecraft potential control for Cluster - implementation and first results".Annales Geophysicae 19.40463(2001):1289-1302.