Ion-Acoustic Solitons in Bi-Ion Dusty Plasma

TL;DR

This paper theoretically investigates ion-acoustic solitons in a warm dusty plasma with two ion species, revealing how dust density influences soliton types and deriving a modified Korteveg-de-Vries equation for critical ion densities.

Contribution

It introduces a modified Korteveg-de-Vries equation accounting for dust density effects and analyzes soliton solutions near the critical negative ion density in bi-ion dusty plasma.

Findings

Critical negative ion density depends on dust density.

Positive nonlinear coefficient for all dust densities.

Existence of both positive and negative potential solitons near critical density.

Abstract

The propagation of ion-acoustic solitons in a warm dusty plasma containing two ion species is investigated theoretically. Using an approach based on the Korteveg-de-Vries equation, it is shown that the critical value of the negative ion density that separates the domains of existence of compressi- on and rarefaction solitons depends continuously on the dust density. A modified Korteveg-de Vries equation for the critical density is derived in the higher order of the expansion in the small parameter. It is found that the nonlinear coefficient of this equation is positive for any values of the dust density and the masses of positive and negative ions. For the case where the negative ion density is close to its critical value, a soliton solution is found that takes into account both the quadratic and cubic nonlinearities. The propagation of a solitary wave of arbitrary amplitude is investigated by the quasi-potential method. It is shown that the range of the dust densities around the critical value within which solitary waves with positive and negative potentials can exist simultaneously is relatively wide.