Solitary kinetic Alfvén wave in a bi-ion plasma with superthermal electrons

Abstract

The dispersion relation and the nonlinear solitary structure of kinetic Alfvén waves (KAWs) have been investigated in bi-ion plasma with superthermal electrons modeled by kappa (κ) distribution. A detailed analysis of the existence condition and the structure of solitary KAW (SKAW) is present. Numerical results indicate there is only the sub-Alfvénic hump type SKAW. For the same parallel phase velocity, the amplitude of SKAW will increase with the increase in the charge number of heavy ion, and with the decrease in the suprathermal index κ and the heavy ion number density. Moreover, the width of SKAW will increase with the decrease in the charge number of heavy ion, and with the increase in the super-thermal index κ and the heavy ion number density. The findings of the present study can be applied to low beta space plasma composed of multi-ion components and suprathermal electrons.