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P: Fachverband Plasmaphysik
P 11: Helmholtz Graduate School II
P 11.1: Vortrag
Dienstag, 14. März 2017, 14:00–14:25, HS 1010
Kinetic waves in non-Maxwellian plasmas — •Patrick Astfalk1,2, Seth Dorfman2, and Frank Jenko1,2 — 1Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, 85748 Garching, Germany — 2Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA
Due to low collisionality, particle velocity distributions in space plasmas can develop and maintain nonthermal features. This makes linear wave analysis particularly challenging since it invalidates the use of simple Maxwell-Boltzmann distributions and necessitate the use of sophisticated numerical tools. Nonthermal deviations from an isotropic Maxwell-Boltzmann distribution can, on the other hand, provide a source of free energy and drive a rich variety of velocity space instabilities. We use a recently developed fully kinetic dispersion relation solver which can process arbitrary distributions obtained from spacecraft measurements and simulation data to carry out a realistic investigation of velocity space instabilities in the solar wind and Earth's magnetosphere such as the ion firehose instability and the right-hand resonant ion beam instability. We compare the results to other solvers based on bi-Maxwellian and anisotropic kappa distributions, and we extend the analysis to quasilinear theory to study the instabilities' saturation due to resonant pitch-angle scattering.