Linear and nonlinear modified electron-acoustic waves

1983 ◽  
Vol 29 (3) ◽  
pp. 409-413 ◽  
Author(s):  
M. Y. Yu ◽  
P. K. Shukla
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Electron Number Density ◽  
Cold Electron ◽  
Number Density ◽  
Electron Number ◽  
Electron Acoustic Waves ◽  
Electron Acoustic Wave ◽  
Linear And Nonlinear ◽  
Electron Acoustic

It is shown that a modified electron-acoustic wave exists in a plasma with distinct hot and cold electron components. The frequency of this wave depends strongly on the cold electron number density. Solitons associated with the modified electron-acoustic waves are also discussed.

Electron-acoustic waves in the laboratory: an experiment revisited

2000 ◽  
Vol 64 (4) ◽  
pp. 433-443 ◽  
Author(s):  
M. A. HELLBERG ◽  
R. L. MACE ◽  
R. J. ARMSTRONG ◽  
G. KARLSTAD
Keyword(s):  
Distribution Function ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
High Frequency ◽  
Hot Electron ◽  
Electron Component ◽  
Temperature Plasma ◽  
Electrostatic Waves ◽  
Electron Acoustic Wave ◽  
Electron Acoustic

High-frequency electrostatic waves have been observed in a two-electron-temperature plasma. Both bi-Maxwellian and Maxwellian-waterbag models were found to be inadequate in explaining the observed dispersion and damping rates. However, modelling of the hot electron component with a κ-distribution function confirms that the experiments represent observation of the electron-acoustic wave in the laboratory.

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.

Linear and nonlinear propagation of electron-acoustic wave in a multi-species plasma

1984 ◽  
Vol 32 (2) ◽  
pp. 283-290 ◽  
Author(s):  
S. Guha ◽  
C. B. Dwivedi
Keyword(s):  
Acoustic Wave ◽  
Density Ratio ◽  
Finite Amplitude ◽  
Nonlinear Propagation ◽  
Effective Parameters ◽  
Ion Temperature ◽  
Ion Density ◽  
Electron Acoustic Wave ◽  
Linear And Nonlinear ◽  
Electron Acoustic

The propagation of an electron-acoustic wave in a plasma consisting of two types of ion and two temperature electrons has been investigated in the linear and nonlinear regimes. The presence of the second species of ion modifies the characteristics of the wave. The analysis has been done for both the finite amplitude and the small amplitude case of the electron-acoustic solitary wave. The ion temperature ratio and the electron density ratio rather than the relative ion density are the effective parameters which govern the amplitude of the electron-acoustic soliton.

scholarly journals Study of nonlinear ion- and electron-acoustic waves in multi-component space plasmas

2008 ◽  
Vol 15 (6) ◽  
pp. 903-913 ◽  
Author(s):  
G. S. Lakhina ◽  
S. V. Singh ◽  
A. P. Kakad ◽  
F. Verheest ◽  
R. Bharuthram
Keyword(s):  
Solitary Waves ◽  
Acoustic Waves ◽  
Ion Beam ◽  
Hot Electron ◽  
Number Density ◽  
Electron Acoustic Waves ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Mach Numbers ◽  
Electron Acoustic

Abstract. Large amplitude ion-acoustic and electron-acoustic waves in an unmagnetized multi-component plasma system consisting of cold background electrons and ions, a hot electron beam and a hot ion beam are studied using Sagdeev pseudo-potential technique. Three types of solitary waves, namely, slow ion-acoustic, ion-acoustic and electron-acoustic solitons are found provided the Mach numbers exceed the critical values. The slow ion-acoustic solitons have the smallest critical Mach numbers, whereas the electron-acoustic solitons have the largest critical Mach numbers. For the plasma parameters considered here, both type of ion-acoustic solitons have positive potential whereas the electron-acoustic solitons can have either positive or negative potential depending on the fractional number density of the cold electrons relative to that of the ions (or total electrons) number density. For a fixed Mach number, increases in the beam speeds of either hot electrons or hot ions can lead to reduction in the amplitudes of the ion-and electron-acoustic solitons. However, the presence of hot electron and hot ion beams have no effect on the amplitudes of slow ion-acoustic modes. Possible application of this model to the electrostatic solitary waves (ESWs) observed in the plasma sheet boundary layer is discussed.

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