Dust acoustic solitary structures in presence of nonthermal ions, isothermally distributed electrons and positrons

TL;DR

This study investigates dust acoustic solitary structures in a multi-species plasma with nonthermal ions, electrons, and positrons, revealing how ion nonthermality and positron concentration influence solitary wave polarity and existence.

Contribution

It introduces a computational scheme to analyze arbitrary amplitude dust acoustic solitary structures considering nonthermal ions, dust temperature, and positron effects, expanding understanding of plasma wave phenomena.

Findings

Only negative potential solitary waves for isothermal ions.

Positive potential solitary waves and double layers occur with strong ion nonthermality.

Positron concentration significantly affects the formation of positive potential double layers.

Abstract

Arbitrary amplitude dust acoustic solitary structures have been investigated in a four component multi-species plasma consisting of negatively charged dust grains, nonthermal ions, isothermally distributed electrons and positrons including the effect of dust temperature. We have used the Sagdeev pseudo-potential method to discuss the arbitrary amplitude steady state dust acoustic solitary structures in the present plasma system. We have designed a computational scheme to draw the existence domains of different dust acoustic solitary structures. We have observed only negative potential solitary waves for isothermal ions. But for strong nonthermality of ions the system supports positive potential solitary waves, positive potential double layers and coexistence of solitary waves of both polarities. The positive potential solitary waves are restricted by the positive potential double layers but negative potential double layer has not been found for any parameter regime. The system does not support dust acoustic supersoliton of any polarity. The concentration of positrons plays an important role in the formation of positive potential double layers. Finally, the phase portraits of the dynamical system have been presented to confirm the existence of different dust acoustic solitary structures.