Regensburg 2007 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 11: Heliosphäre

EP 11.3: Vortrag

Donnerstag, 29. März 2007, 10:15–10:30, H46

Analytic relations between the upstream and downstream distribution functions of an ion plasma crossing an MHD shock — •Mark Siewert and Hans Jörg Fahr — Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn

MHD shocks dominate the vast majority of models aiming to describe physical processes in astrophysical plasmas. Usually, these shocks are described using a set of MHD jump conditions as functions of a few low-order velocity moments of the distribution function. However, in the presence of a magnetic field, these jump conditions are underdetermined, with the downstream pressure anisotropy usually taking the part of the missing parameter. Amining to arrive at a more precise description of the MHD shock, we have recently developed a Boltzmann-kinetic model of the shock transition region. Fully analytic relations between the upstream and the downstream plasma distribution functions are presented, as well as physical implications following from these results.