Seminar: Hybrid modeling of local ion acceleration and relaxation in the solar corona and the solar wind

Hybrid modeling of local ion acceleration and relaxation in the solar corona and the solar wind

by Yana Maneva, CmPA, KU Leuven, Celestijnenlaan 200B, Heverlee 3001, Belgium.

Plasma heating and cooling in the solar wind is a dynamic process, which can occur sporadically at various heliocentric distances. Furthermore the solar wind is composed of multiple ion populations, which are observed to move relative to each other with different bulk velocities. Observational data from various spacecraft shows compelling evidence for in situ ion heating via coherent structures, turbulence and wave-particle interactions, as well as plasma cooling regulated by linear or non-linear kinetic micro-instabilities. In the vicinity of the solar corona the heavy ions, such as alpha particles and oxygen ions for example, stream much faster than the protons and this relative drift speed can decrease with heliospheric distance as the fast solar wind streams approach the Earth. The two main scenarios of exploring the non-thermal heating and acceleration of minor ions in the solar wind are based on currents sheets and waves. This talk will mainly focus on the wave-based heating and acceleration mechanisms through linear and nonlinear wave-particle interactions and related energy exchange. We have performed hybrid numerical simulations (with fluid electrons and kinetic protons and minor ions) to study the effect of the different types of fluctuations and the related plasma instabilities. We investigate which waves are most efficient in scattering the ions and which instabilities might be responsible for their subsequent relaxation. The results are applicable for local small-scale heating and acceleration processes in collisionless coronal holes and the solar wind.

Dijous 18 de gener de 2018, a les 11 h.
Sala de Seminaris, 3r pis Dpt. Física
Edifici Mateu Orfila , UIB

Organitza: Grup de Física Solar i IAC3