Electrostatic Dust Acoustic Solitons in Pair-Ion-Electron Plasmas

Abstract

Using the reductive perturbation method, a Korteweg-de Vries (KdV) equation is derived to study the nonlinear properties of electrostatic collisionless dust acoustic solitons in pair-ion-electron (p-i-e) plasmas. The fluid model is chosen for positive ions, negative ions, and the fraction of electrons and charged (both positive and negative) dynamic dust particles. It is realized that electrostatic hump structures can be found when the dust particles are positively charged, and electrostatic dip structures can be detected for negatively charged dust particles. Numerical solutions for these dust acoustic solitons are plotted and their characteristics are discussed. It is found that the amplitude and width of the electrostatic dust acoustic solitons increase when the density of the dust particles and/or the temperature of the negative ions increases, and that the amplitude and width of these solitons decrease when the temperature of the positive ions increases. As pair-ion plasmas mimic electron-positron plasmas, our results might be helpful in understanding the nonlinear dust acoustic solitary waves in super dense astronomical bodies like neutron stars.

Electrostatic solitary waves in dusty pair-ion plasmas

“…Recently, there has been a growing interest in investigating the properties of electrostatic waves in pair-ion plasmas (see, e.g., Refs. [18,19]). However, to our knowledge, no detailed theory has been made to study the electrostatic small-as well as large-amplitude waves in dusty pair-ion plasmas with positively charged dusts.…”

Oblique propagation of dust ion-acoustic solitary waves in a magnetized dusty pair-ion plasma

“…It is also found that the phase speed of the DIA modes remain constant as k → 0. These interesting features of DIA and DIC-like modes have not been observed before in pair-ion plasmas [4][5][6][7][8] (iii) Effect of negative to positive ion mass ratio:…”

“…As a result, the frequency gap between the modes for k > k c (k < k c ) is found to increase (decrease). Thus, the presence of immobile charged dusts not only modifies the wave frequency and the phase speed, but also reduces the frequency gap between the DIA and DIC-like modes, which can not be observed in pure pair-ion plasmas with equal mass and temperature 2,3,5,6 . However, some different features of increasing the frequency gap (not the decreasing trend) between DIA and DIC modes were found, e.g., for oblique propagation of electron-acoustic waves in a magnetized plasma without charged dusts 31 .…”

“…Later, a criterion for the description of pure pair-ion plasmas has been investigated by Saleem 3 . Recently, there has been a growing interest in investigating the properties of electrostatic waves in pair-ion plasmas in linear and nonlinear regimes (See, e.g., [4][5][6][7][8][9][10][11]. To mention few, Misra et al 4 had investigated the propagation of dust ion-acoustic (DIA) solitary waves and shocks (SWS) in an unmagnetized dusty negative-ion plasma.…”

“…Rosenberg a) Electronic mail: apmisra@visva-bharati.ac.in; apmisra@gmail.com and Merlino 11 studied the ion-acoustic instability in a dusty negative-ion plasma. The theory of dust-acoustic solitons in unmagnetized pair-ion-electron plasmas has been investigated through the description of Kortewegde Vries (KdV) equation 5 . More recently, the linear and nonlinear properties of both small-and large-amplitude DIA solitary waves in an unmagnetized pair-ion plasma with immobile charged dusts have been studied 8 .…”