Volumes and Issues  Contents of Issue 8  Special Issue

Ann. Geophys., 23, 2813-2823, 2005
www.ann-geophys.net/23/2813/2005/
© European Geosciences Union 2005

Spacecraft potential control for Double Star

K. Torkar¹, H. Arends², W. Baumjohann¹, C. P. Escoubet², A. Fazakerley³, M. Fehringer², G. Fremuth¹, H. Jeszenszky¹, G. Laky¹, B. T. Narheim⁴, W. Riedler¹, F. Rüdenauer⁵, W. Steiger⁵, K. Svenes⁴, and H. Zhao^6
1Space Research Institute, Austrian Academy of Sciences, A-8042 Graz, Austria
²ESA/ESTEC, NL-2200 AG Noordwijk, The Netherlands
³Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, UK
⁴Norwegian Defence Research Establishment (FFI), N-2007 Kjeller, Norway
⁵Austrian Research Centers Seibersdorf, A-2444 Seibersdorf, Austria
⁶Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, P. R. China

Abstract. The spacecraft potential of Double Star TC-1 is positive in large parts of the orbits due to the photo-effect from solar EUV irradiation. These positive potentials typically disturb low energy plasma measurements on board. The potential can be reduced, and thereby the particle measurements improved, by emitting a positive ion beam. This method has successfully been applied on several other spacecraft and it has also been chosen for TC-1. The instrument TC-1/ASPOC is a derivative of the Cluster/ASPOC instruments, from which it has inherited many features. The paper describes the adaptations and further developments made for the ion emitters and the electronics. The instrument performs very well and can support higher beam currents than on Cluster. The expected significant improvement of the low energy particle measurements on board was indeed observed. The modifications of the electron distributions are analysed for a one-time interval when the spacecraft was located in the magnetosheath. The change in the potential due to the ion beam was determined, and first studies of the 3-D electron distributions in response to the spacecraft potential control have been performed, which indicate that the method works as expected.

Full Article (PDF, 5957 KB)

Citation: Torkar, K., Arends, H., Baumjohann, W., Escoubet, C. P., Fazakerley, A., Fehringer, M., Fremuth, G., Jeszenszky, H., Laky, G., Narheim, B. T., Riedler, W., Rüdenauer, F., Steiger, W., Svenes, K., and Zhao, H.: Spacecraft potential control for Double Star, Ann. Geophys., 23, 2813-2823, 2005.   Bibtex   EndNote   Reference Manager