Arbitrary amplitude kinetic Alfvén solitary waves and double layers in a non-Maxwellian plasma

Abstract

To investigate the existence of kinetic Alfvén wave solitons, warm adiabatic ions and kappa distributed electrons are considered in a magnetized plasma. The kappa distribution (having the spectral index κ) is a velocity distribution that has a high energy tail but approaches the Maxwellian when κ→∞. In this work, by using the Sagdeev pseudopotential method, an exact analytical expression for arbitrary amplitude solitary kinetic Alfvén wave is derived. For different sets of plasma parameter values, the Sagdeev potential Ψ (ϕ) has been calculated numerically. It is found that the spectral index κ plays a significant role in determining the shape and size of the solitary waves and double layers. Also, it is observed that both compressive solitary waves and double layers exist depending on the values of different plasma parameters.