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

TL;DR

This paper investigates how kinetic Alfvén waves contribute to particle acceleration and heating in the solar corona, emphasizing the effects of suprathermal particles and plasma parameters on energy transport and wave damping.

Contribution

It provides a detailed analysis of KAWs' role in coronal heating using kinetic plasma theory, highlighting the influence of suprathermal particles and temperature ratios on wave dynamics.

Findings

Perturbed EM fields are significantly affected by  and T_e/T_i.

Parallel Poynting flux dissipates gradually at lower er values.

Group velocity of KAWs increases as er decreases, extending energy transport.

Abstract

The heating of the solar corona and solar wind, through suprathermal particles and kinetic Alfv\'en waves within the 0 - 10 $R_{\rm Sun}$ 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 \kappa and 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 Alfv\'en 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 \kappa values. The perpendicular flux dissipates quickly over shorter distances. Power deposition in solar flux tubes is significantly influenced by \kappa and 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 \kappa values, and the damping length is enhanced under lower \kappa, 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.