Modulational instability of electron-acoustic waves in plasmas with superthermal electrons

2012 ◽  
Vol 90 (7) ◽  
pp. 661-666 ◽  
Author(s):  
Parvin Eslami ◽  
Marzieh Mottaghizadeh ◽  
Hamid Reza Pakzad
Keyword(s):  
Acoustic Waves ◽  
Modulational Instability ◽  
Perturbation Technique ◽  
Density Ratio ◽  
Wave Number ◽  
Superthermal Electrons ◽  
Electron Acoustic Waves ◽  
Instability Growth ◽  
Cold Electrons ◽  
Electron Acoustic

The propagation of electron-acoustic waves (EAWs) in plasmas composed of inertial cold electrons, hot superthermal electrons, and stationary ions is investigated. By means of the reduction perturbation technique, a nonlinear Schrödinger equation is derived and the modulation instability of EAW is analyzed, where the superthermal parameter is found to be of significant importance. It is shown that the presence of superthermal electrons enhances the critical wave number of the modulational instability of EAWs. Besides, due to the presence of the superthermal electrons, EAWs are stable on a vaster region. Moreover, the modulational instability growth rate is lower for a larger population of superthermal electrons. Further, it is shown that increasing values of the relative density ratio α = ne0/nc0 shifts the instability domain to lower values of wave number k.

Nonlinear modulation of ion-acoustic waves in two-electron-temperature plasmas

2010 ◽  
Vol 76 (2) ◽  
pp. 169-181 ◽  
Author(s):  
A. ESFANDYARI-KALEJAHI ◽  
I. KOURAKIS ◽  
M. AKBARI-MOGHANJOUGHI
Keyword(s):  
Electron Temperature ◽  
Acoustic Waves ◽  
Modulational Instability ◽  
Perturbation Technique ◽  
Density Ratio ◽  
Cold Electron ◽  
Ion Temperature ◽  
Ion Acoustic Waves ◽  
Ion Acoustic ◽  
Nonlinear Modulation

AbstractThe amplitude modulation of ion-acoustic waves is investigated in a plasma consisting of adiabatic warm ions, and two different populations of thermal electrons at different temperatures. The fluid equations are reduced to nonlinear Schrödinger equation by employing a multi-scale perturbation technique. A linear stability analysis for the wave packet amplitude reveals that long wavelengths are always stable, while modulational instability sets in for shorter wavelengths. It is shown that increasing the value of the hot-to-cold electron temperature ratio (μ), for a given value of the hot-to-cold electron density ratio (ν), favors instability. The role of the ion temperature is also discussed. In the limiting case ν = 0 (or ν → ∞), which correspond(s) to an ordinary (single) electron-ion plasma, the results of previous works are recovered.

Modulational instability of electron-acoustic waves: an application to auroral zone plasma

2006 ◽  
Vol 41 (1) ◽  
pp. 151-156 ◽  
Author(s):  
T. S. Gill ◽  
H. Kaur ◽  
S. Bansal ◽  
N. S. Saini ◽  
P. Bala
Keyword(s):  
Acoustic Waves ◽  
Modulational Instability ◽  
Auroral Zone ◽  
Electron Acoustic Waves ◽  
Electron Acoustic

On the existence of weak stationary electron-acoustic double layers

1993 ◽  
Vol 49 (2) ◽  
pp. 283-293 ◽  
Author(s):  
R. L. Mace ◽  
M. A. Hellberg
Keyword(s):  
Acoustic Waves ◽  
Perturbation Technique ◽  
Broad Band ◽  
Mkdv Equation ◽  
Double Layers ◽  
Dynamical Equations ◽  
Electron Acoustic Waves ◽  
Electron Acoustic Wave ◽  
Electron Acoustic ◽  
Parameter Values

The recent interest in the electron-acoustic wave as a source of broad-band electrostatic noise in the terrestrial magnetosphere makes it interesting to ask whether it can support stationary electrostatic double layers. We investigate this problem in a fluid plasma composed of cool ions, cool electrons and a hot Boltzmann electron component – which is known to support electron-acoustic waves. Although a formal application of the reductive perturbation technique to our dynamical equations leads to an mKdV equation for electron-acoustic waves, it is found that within the present physical model the consistency conditions and required ordering of the coefficients cannot be satisfied simultaneously for reasonable parameter values. As a consequence, it is shown that the neglect of the φ(2) term in deriving the mKdV equation is unjustified under general circumstances, and furthermore that the cubic nonlinearity introduced by the mKdV equation is negligible when compared with this term. Finally, we are led to conclude that stationary, weak electron-acoustic double layers cannot exist in such a plasma.

Modulational Instability Of Dust Electron Acoustic Waves In Superthermal Dusty Plasmas

2011 ◽  
Author(s):  
N. S. Saini ◽  
S. Sultana ◽  
I. Kourakis ◽  
Vladimir Yu. Nosenko ◽  
Padma K. Shukla ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Modulational Instability ◽  
Dusty Plasmas ◽  
Electron Acoustic Waves ◽  
Electron Acoustic
Sign in / Sign up

Export Citation Format

Share Document