Influence of superthermal electrons on obliquely propagating ion-acoustic solitons in magnetized plasmas

Abstract

The effect of superthermal electrons, modeled by a Lorentzian velocity distribution function, on the oblique propagation characteristics of linear and nonlinear ion-acoustic waves in an electron–ion plasma in the presence of a uniform external magnetic field is investigated. First, the linear dispersion relations of the fast and slow modes are obtained. It is shown that the superthermal electrons make both modes propagate with smaller phase velocities. Then, the Korteweg–de Vries equation describing the propagation of nonlinear slow and fast ion-acoustic waves is derived. It is shown that the presence of superthermal electrons has a significant influence on the nature of magnetized ion-acoustic solitons. That is, for a larger population of the superthermal electrons, the soliton velocity of both modes in the laboratory frame significantly decreases and the soliton are slimmer, and on approaching the Maxwellian limit, the width becomes maximum.