Ion-acoustic Gardner solitons in a four-component nonextensive multi-ion plasma
- PDF / 2,779,436 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 19 Downloads / 199 Views
LASMA DYNAMICS
Ion-Acoustic Gardner Solitons in a Four-Component Nonextensive Multi-Ion Plasma1 N. Jannat, M. Ferdousi, and A. A. Mamun Department of Physics, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh e-mail: [email protected] Received June 15, 2015; in final form, September 21, 2015
Abstract—The nonlinear propagation of ion-acoustic (IA) solitary waves (SWs) in a four-component nonextensive multi-ion plasma system containing inertial positively charged light ions, negatively charged heavy ions, as well as noninertial nonextensive electrons and positrons has been theoretically investigated. The reductive perturbation method has been employed to derive the nonlinear equations, namely, Korteweg−de Vries (KdV), modified KdV (mKdV), and Gardner equations. The basic features (viz. polarity, amplitude, width, etc.) of Gardner solitons are found to exist beyond the KdV limit and these IA Gardner solitons are qualitatively different from the KdV and mKdV solitons. It is observed that the basic features of IA SWs are modified by various plasma parameters (viz. electron and positron nonextensivity, electron number density to ion number density, and electron temperature to positron temperature, etc.) of the considered plasma system. The results obtained from this theoretical investigation may be useful in understanding the basic features of IA SWs propagating in both space and laboratory plasmas. DOI: 10.1134/S1063780X16070059
1. INTRODUCTION The dynamics of ion-acoustic (IA) waves, which is one of the basic wave processes in plasma, has been studied for several decades both theoretically and experimentally. Nonlinear theory for these waves was first considered by Sagdeev [1], where their basic properties were studied using a mechanical analogy. It has been established that stationary IA waves can exist in the form of periodic or solitary waves (SWs). The first experimental observation of IA soliton has been made by Ikezi et al. [2]. The IA solitary waves (SWs) are one of the important nonlinear phenomena in a plasma system. The study of IA SWs in plasmas are very important because of its vital role in understanding the nonlinear features of localized electrostatic disturbances in space environments [3–5] and laboratory devices [2, 6, 7]. The basic features of IA SWs were first theoretically predicted by Washimi and Tanuity [8] by assuming an ideal plasma containing cold ions and isothermal electrons. Later, the IA SWs were investigated both theoretically and numerically by a number of authors [9–11], who assumed cold ions and non-adiabatic electrons following vortex-like distribution [9], bi-Maxwellian distribution [10], and non-thermal distribution [11]. A multi-ion plasma system is a system containing more than one types of ions [12]. First the multi-ion plasma was considered and examined in [13]. Then 1 The article is published in the original.
multi-ion plasma have been investigated by a large number of authors [14, 15]. These investigations indicate that the collisionless multi-ion plasma is a comm
Data Loading...
