Kinetic Alfv\'en waves in the temperature anisotropic space plasma with a kappa-Maxwellian distribution

TL;DR

This study investigates how kinetic Alfvén waves behave in space plasma with a kappa-Maxwellian distribution, revealing differences in wave frequency and damping compared to Maxwellian plasma, especially in low beta conditions.

Contribution

It provides a kinetic analysis of wave dispersion and damping in kappa-Maxwellian plasma, highlighting the effects of the kappa parameter on wave characteristics in low beta space plasma.

Findings

Wave frequency of kinetic Alfvén waves is higher in kappa-Maxwellian plasma.

Damping rate of kinetic Alfvén waves is stronger in kappa-Maxwellian plasma.

Modified ion acoustic waves show different frequency and damping behaviors depending on wave region.

Abstract

The dispersion and damping rate of kinetic Alfv\'en waves are studied in temperature anisotropic space plasma with kappa-Maxwellian distribution. Employing a kinetic approach, the wave frequency and damping rate of kinetic Alfv\'en waves and the modified ion acoustic waves are derived in a low \b{eta} plasma, which both depend on the parameters \k{appa} and . The numerical analyses show that the wave frequency of kinetic Alfv\'en waves is larger in kappa-Maxwellian plasma than that in Maxwellian case. The wave frequency of the modified ion acoustic waves in kappa-Maxwellian plasma is larger in the short-wave region but smaller in the long-wave region than that in Maxwellian case. Again, we found that the damping rate of kinetic Alfv\'en waves in kappa-Maxwellian plasma is stronger than that in Maxwellian case. The damping rate of modified ion acoustic waves in kappa-Maxwellian plasma is stronger in the short-wave region but weaker in the long-wave region than that in Maxwellian case. The impact of the parameter on the two modes is relatively small because we consider the low \b{eta} case. These results are helpful for us to understand better the characteristics of kinetic Alfv\'en waves in space plasma.