SIII 22Kinetics of Electrons in the Solar Corona and Wind

C. Vocks , G. J. Mann 
The velocity distribution functions (VDFs) of electrons as measured in the solar wind show pronounced deviations from a Maxwellian. They seem to be composed of a thermal core and energetic tails, called halo. These VDFs can be fitted very well by kappa distributions. The formation of the energetic tails in the corona or in the solar wind is investigated. The relaxation of a kappa distribution under the influence of Coulomb collisions in a coronal plasma is calculated. This allows an estimation whether the energetic tails of the VDFs can be formed in the corona. A kinetic model for electrons is presented. The model electron VDF depends on two velocity coordinates and on one spatial coordinate parallel to the background magnetic field. Coulomb collisions and wave-particle interactions are considered. With this model, electron VDFs can be calculated from the transition region up into the solar wind.