Stuttgart 2012 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 19: Komplexe und staubige Plasmen
P 19.5: Vortrag
Donnerstag, 15. März 2012, 15:25–15:40, V57.02
Spacecraft-plasma interactions in Saturn's magnetosphere — •Victoria Yaroshenko1, Wojciech Miloch2, Hubertus Thomas1, and Gregor Morfill1 — 1Max-Planck-Institut for Extraterrestial Physics, Garching, Germany. — 2Department of Physics and Technology, University of Tromsø,
Three-dimensional particle-in-cell self-consistent code has been employed to model spacecraft-plasma interactions in the regime relevant for Cassini during the Saturn orbit insertion (SOI) flyby. Plasma parameters derived from Cassini plasma spectrometer measurements at the SOI flyby are used as input data. Modeling includes photoemission due to the solar UV radiation, two populations of ions, plasma flows and the flyby geometry. It is found that in the outer magnetosphere the positive spacecraft potential is primary due to the photoelectron production on the Sun-exposed surface of the orbiter. In the inner plasmasphere the SC charges to a negative potential up to a few electron temperatures. Simulations display different spatial structures of the plasma particle densities and the self-consistent potential surrounding the SC at different distances from Saturn. Three plasma constituents (electrons, water group ions and protons) produce a new kind of plasma wake with a self-consistent separation between the plasma components in the electric field of the orbiter. The obtained results are of importance for studies of the dust-plasma interactions in the planetary rings, and for reliable interpretations of the electric field and plasma parameter measurements.