Ion-acoustic solitons in plasma: an application to Saturn’s magnetosphere

Abstract

Soliton formation in plasma is addressed. Nonlinear acoustic waves in plasma where the combined effects of bounded spherical geometry and the transverse perturbation are dealt with, in two-temperature electron plasma are studied. Using the perturbation method, a spherical Kadomtsev-Petviashvili equation (SKP) that describes the ion acoustic waves is derived. The plasma is modeled by a kappa distribution function for both electrons components as found in Saturn’s magnetosphere. It is found that parameters taken into account have significant effects on the properties of nonlinear waves. The model is applied to Saturn’s magnetosphere, where two temperature superthermal electrons are present. Hence, ion acoustic waves are deduced for three regions, namely, the inner, the intermediate and the outer Saturn’s magnetosphere. We point out, that this work has been motivated by recent observations of Saturn’s magnetosphere.