A study of particle acceleration, heating, power deposition, and the damping length of kinetic Alfvén waves in non-Maxwellian coronal plasma

Abstract

The heating of the solar corona and solar wind, through suprathermal particles and kinetic Alfvén waves within the 0 - 10 $R_{\mathrm{Sun}}$ range, has been a subject of great interest for many decades. This study investigates the acceleration and heating of charged particles and the role of KAWs in the solar corona. We investigate how KAWs transport energy and accelerate/heat the charged particles, focusing on the behavior of perturbed EM fields, Poynting flux vectors, net power transfer, resonant particle speed, group speed, and the damping length of KAWs. The study examines how these elements are influenced by suprathermal particles κand the electron-to-ion temperature $T_e/T_i$. We use kinetic plasma theory coupled with the Vlasov-Maxwell model to investigate the dynamics of KAWs and particles. We assume a collisionless, homogeneous, and low-beta electron-ion plasma in which Alfvén waves travel in the kinetic limits. The results show the perturbed EM fields are significantly influenced by $\kappa$ and $T_e/T_i$. We evaluate both the parallel and perpendicular Poynting fluxes and find that the parallel Poynting flux dissipates gradually for lower κvalues. The perpendicular flux dissipates quickly over shorter distances. Power deposition in solar flux tubes is significantly influenced by κand Te/Ti. We find that particles can heat the solar corona over long distances in the parallel direction and short distances in the perpendicular direction. The group velocity of KAWs increases for lower κvalues, and the damping length is enhanced under lower κ, suggesting longer energy transport distances. These findings offer a comprehensive understanding of particle-wave interactions in the solar corona and wind, with potential applications for missions such as the Parker Solar Probe (PSP), and can also apply to other environments.

Accepted for publication in the Astronomy and Astrophysics (A&A) journal (2024)