Ponderomotive forces in magnetized non-thermal space plasmas due to cyclotron waves

TL;DR

This paper evaluates the influence of non-thermal Kappa distributions on the ponderomotive force in magnetized space plasmas, revealing significant effects relevant to various space environments like the solar wind and magnetosphere.

Contribution

It provides a detailed analysis of how Kappa distributions affect the ponderomotive force in low-temperature magnetized plasmas, extending understanding of non-thermal effects in space physics.

Findings

Non-thermal effects significantly influence ponderomotive force factors.

Kappa distribution impacts are relevant across multiple space environments.

Even near-cold plasmas exhibit notable Kappa effects on ponderomotive phenomena.

Abstract

The ponderomotive force is involved in a variety of space plasmas phenomena which are characterized by the family of Kappa distributions. Therefore, evaluating these nonthermal effects in the ponderomotive force is required. The Washimi and Karpman ponderomotive interaction due to cyclotron waves is evaluated for different space conditions considering low-temperature magnetized plasmas described by an isotropic Kappa distribution and with a wave propagation parallel to the background magnetic field. We performed a brief analysis of the influence of the Kappa distribution in the dispersion relation for a low-temperature plasma expansion at the lowest order in which the thermal effects are appreciated without considering the damping characteristics of the wave. The different factors of the ponderomotive force are obtained and analyzed separately as a function of the wavenumber, the spectral index $\kappa$, and the plasma beta. We have found a relevant influence of the non-thermal effects in all the factors of the ponderomotive force for magnetized plasmas. The effect of the kappa distribution has been evaluated for a wide variety of space environments as the solar wind and the different regions of our magnetosphere where it has been found that these results can be relevant for the solar wind, the magnetosheath, the plasmasheet, and the polar cusps. We have also analyzed the role of the non-thermal effect in the induced Washimi and Karpman ponderomotive magnetization in the context of spatial plasmas and the total power radiated associated with it. We find that even for nearly cold magnetized plasmas and waves far from the resonances the effect of the kappa parameter in the ponderomotive force cannot be neglected. This suggests a significant role of the Kappa distribution in ponderomotive phenomena of space physics.