Fully nonlinear ion-acoustic solitary waves in a plasma with positive-negative ions and nonthermal electrons

Abstract

Properties of fully nonlinear ion-acoustic solitary waves in a plasma with positive-negative ions and nonthermal electrons are investigated. For this purpose, the hydrodynamic equations for the positive-negative ions, nonthermal electron density distribution, and the Poisson equation are used to derive the energy integral equation with a new Sagdeev potential. The latter is analyzed to examine the existence regions of the solitary pulses. It is found that the solitary excitations strongly depend on the mass and density ratios of the positive and negative ions as well as the nonthermal electron parameter. Numerical solution of the energy integral equation clears that both positive and negative potentials exist together. It is found that faster solitary pulses are taller and narrower. Furthermore, increasing the electron nonthermality parameter (negative-to-positive ions density ratio) decreases (increases) the localized excitation amplitude but increases (decreases) the pulse width. The present model is used to investigate the solitary excitations in the (H+,O2−) and (H+,H−) plasmas, where they are presented in the D- and F-regions of the Earth's ionosphere. This investigation should be helpful in understanding the salient features of the fully nonlinear ion-acoustic solitary waves in space and in laboratory plasmas where two distinct groups of ions and non-Boltzmann distributed electrons are present

Solitons and double-layers of electron-acoustic waves in magnetized plasma; an application to auroral zone plasma

“…Where the energetic electrons/ions were described by the nonthermal distribution. The latter is now being a common feature of the Earth's atmosphere and, in general, it is turning out to be a characteristic feature of space plasmas (see e.g., Asbridge et al 1968;Lundin et al 1987Lundin et al , 1989Hall et al 1991;Pillay and Verheest 2005;Gill et al 2007;Sabry et al 2009;El-Labany et al 2010). For example, the observations of nonthermal ions in the Earth's bow-shock region by the Vela satellite has been noted (Lundin et al 1989).…”

Ion-acoustic double layers in magnetized positive-negative ion plasmas with nonthermal electrons

“…The energetic electrons/ions were described by a new distribution called nonthermal distribution. The latter is now being a common feature of the Earth's atmosphere and, in general, it is turning out to be a characteristic feature of space plasmas (see, for example, Asbridge et al 1968;Lundin et al 1989;Gill et al 2007;Sabry et al 2009). For example, the observations of nonthermal ions in the Earth's bow-shock region by the Vela satellite has been noted (Asbridge et al 1968).…”

Multi-dimensional instability of dust-ion-acoustic solitary structure with opposite polarity ions and non-thermal electrons

“…(1)(2)(3)(4)(5). To do so, the following stretched coordinates [31][32][33][34][35][36][37] are introduced…”

“…Very recently many authors have studied the nonlinear propagation of ion-acoustic (IA) solitary waves (SWs) [1][2][3][4] dust-ion-acoustic (DIA) SWs [5][6][7][8][9], dust-acoustic (DA) SWs [10][11][12][13][14] in a multi-ion plasmas, as negative ions can be found in space [15,16] and laboratory [17][18][19] as well as positive ions. In multi-ion plasmas, there exist fast and slow mode.…”