ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-21-915-2003 Spacecraft potential during an active experiment: a comparison of experimental results with a simple model Žilavý P. 1 Přech L. 1 Nĕmeček Z. 1 Šafránková J. 1 Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, 180 00 Praha 8, Czech Republic 30 04 2003 21 4 915 922 Copyright: © 2003 P. Žilavý et al. 2003 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/21/915/2003/angeo-21-915-2003.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/21/915/2003/angeo-21-915-2003.pdf

The Active Plasma Experiment (APEX) used intensive electron beam and/or a release of the low-energy Xenon plasma to study dynamic processes in the magnetosphere and upper ionosphere. It was shown by Prech et al. (1999) that the release of the Xe plasma increases the spacecraft potential when the ambient plasma density is low, but decreases it when the density is high enough. In the present paper, a simple computer model of the dust particle charging has been adapted for a calculation of the potential difference between a planar probe and a spherical satellite moving in the ionospheric plasma. The influence of a quasineutral plasma emission on the measured spacecraft potential difference is discussed and the calculated results are compared with experimental data from the APEX project.<br><br><b>Key words. </b>Ionosphere (active experiments)