Regensburg 2007 – scientific programme
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EP: Fachverband Extraterrestrische Physik
EP 10: Poster
EP 10.12: Poster
Wednesday, March 28, 2007, 18:00–20:00, H46
linearly unstable modes and nonlinear saturation mechanism in coronal current-driven plasma — •kuang wu lee1, nina elkina1,2, and jörg büchner1 — 1Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str.2, 37191 Katlenburg-Lindau, Germany. — 2M.V. Keldysh Institute for Applied Mathematics Miusskaya sq., 4 Moscow 125047, Russia
We investigate the linear stability of a current-driven system in magnetized coronal plasma for all direction of propagation, which is referred to the direction of magnetic field and drift velocity. We mainly focus on low-frequency electrostatic modes including ion-acoustic, Buneman and lower-hybrid waves driven by electron current. Current-driven instabilities result in anomalous transports (anomalous resistivity, heat conduction etc.) of turbulent plasma inside current-sheet layer. The principle effect of resulting instabilities is the large amplitude electrostatic wave developed therein plays a role as obstacle, so that its potential barrier stops some electrons, which accounts to anomalous resistivity. To study the linearly unstable modes, we use kinetic as well as multifluid description. To consider the essential physics we apply appropriate equation of states, which describes response of plasma species properly. The estimation of saturation level of strong turbulence is made by considering particle trapping in the generated potential wells. This investigation is used as a prerequisite step to a nonlinear treatment, which is carried out by means of the kinetic simulation of turbulence in plasma, as well as development of the connection between large and small scale phenomena in plasma.