HR: 0830h
AN: SH21B-0140    [PDF]
TI: Generation of Suprathermal Electrons by Resonant Interaction with Whistler Waves in the Solar Corona and Wind
AU: * Vocks, C
EM: vocks@ssl.berkeley.edu
AF: Space Sciences Laboratory, UC Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Mann, G
EM: gmann@aip.de
AF: Astrophysikalisches Institut Potsdam, An der Sternwarte 16, Potsdam, 14482 Germany
AB: Observations of solar wind electron velocity distribution functions (VDFs) show pronounced deviations from a Maxwellian. The number of suprathermal electrons is strongly enhanced even under quiet solar conditions. An assessment of the relaxation of a non-Maxwellian coronal electron VDF shows that a coronal origin of these suprathermal electrons is possible. A model for the acceleration of suprathermal electrons based on resonant interaction with whistler waves is presented. This interaction is characterized by pitch-angle diffusion of the electrons in the reference frame of the waves. In the plasma rest frame, this leads to a significant acceleration of electrons from small sunwards velocities parallel to the background magnetic field to high speeds perpendicular to it. A kinetic model is developed to study this mechanism in detail and to investigate the overall evolution of an electron VDF from the transition region into the interplanetary space. Simulation results for the open magnetic structure of a coronal funnel are presented. In the energy range of several keV, they show a focussing of the suprathermal electrons in interplanetary space towards a narrow "strahl" and a strong enhancement of suprathermal electron fluxes due to whistler waves. Simulation results for higher energies of several 10 keV are also presented, and effects of other wave modes than whistler waves on the electron VDF are discussed.
DE: 2118 Energetic particles, solar
DE: 2164 Solar wind plasma
DE: 7511 Coronal holes
DE: 7867 Wave/particle interactions
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting