Heidelberg 2006 – wissenschaftliches Programm
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EP: Extraterrestrische Physik
EP 6: Poster
EP 6.12: Poster
Dienstag, 14. März 2006, 14:00–16:30, C
Charging of dust grains within Saturn’s magnetosphere — •Uwe Beckmann1, Sascha Kempf1, Ralf Srama1, Georg Moragas-Klostermeyer1, Stefan Helfert1, and Eberhard Grün1,2 — 1MPI für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg — 2University of Hawaii, 1680 East West Road POST 512c, Honolulu, HI 96822, USA
Saturn’s huge E ring is composed of submicron grains and extends from three to at least nine Saturnian radii (Saturnian radius RS = 60330 km). Since the ring particles are exposed to an ambient plasma the particles rapidly get charged up. Knowing the electrostatic potentials of the grains is important to describe the interaction of the charged grains with Saturn’s strong magnetic field correctly.
Since July 2004, the Cassini spacecraft orbits Saturn, and traversed several times through the E ring. The Cosmic Dust Analyser (CDA) onboard of the spacecraft allows to measure the charge simultaneously with the mass and speed of the grains what in turn allows to determine the corresponding electrostatic potentials.
Here we present a comparison of grain potentials based on in-situ measurements with model calculations of the grain charging within the E ring based on the most recent plasma data. Our results suggest that the CDA mass calibration is applicable for the ring particles.