Long wavelength ion-acoustic waves in a magneto-plasma in a gravitational field

1970 ◽  
Vol 4 (3) ◽  
pp. 617-627 ◽  
Author(s):  
C. H. Liu
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Static Magnetic Field ◽  
Acoustic Waves ◽  
Fluid Dynamic ◽  
Debye Length ◽  
Ion Acoustic Waves ◽  
Long Wavelength ◽  
Special Cases ◽  
Ion Acoustic

Ion-acoustic waves propagating in a collision-free, gravity-supported plasma in a static magnetic field are studied with a linearized Vlasov equation. The dispersion relation is derived in the limit of vanishing electron to ion mass ratio and wavelength much larger than the Debye length. From this dispersion relation it is shown that the well-known fluid dynamic steepening tendency of waves propagating in the direction of decreasing density is competing with the effect of Landau damping. Depending on the ratio of electron and ion temperatures, the direction of propagation and the strength of the static magnetic field, waves of wavelengths of the order of the scale height or even greater are shown to be damped. Several special cases are discussed.

Landau damping of long wavelength ion acoustic waves in a collision-free plasma with a gravity field

1969 ◽  
Vol 3 (1) ◽  
pp. 13-20 ◽  
Author(s):  
D. Parkinson ◽  
K. Schindler
Keyword(s):  
Gravity Field ◽  
Acoustic Waves ◽  
Fluid Dynamic ◽  
Scale Height ◽  
Landau Damping ◽  
Ion Acoustic Waves ◽  
Equilibrium Plasma ◽  
Long Wavelength ◽  
Ion Acoustic ◽  
Free Plasma

Ion acoustic waves propagating in a collision-free gravity-supported one-dimeiisional plasma are studied, including conditions where the wavelength is of the order of the scale height of the equilibrium plasma. It turns out that the fluid dynamic steepening tendency of waves propagating in the direction of decreasing density is overcome by Landau damping up to wavelengths of the order of the scale height or even larger, depending on the ratio of the electron and the ion temperatures.

scholarly journals Modulational instability in the beat-wave generation

1988 ◽  
Vol 6 (2) ◽  
pp. 199-210 ◽  
Author(s):  
D. Pesme ◽  
S. J. Karttunen ◽  
R. R. E. Salomaa ◽  
G. Laval ◽  
N. Silvestre
Keyword(s):  
Dispersion Relation ◽  
Acoustic Waves ◽  
Wave Process ◽  
Short Pulse ◽  
Modulational Instability ◽  
Ion Acoustic Waves ◽  
Long Wavelength ◽  
Ion Acoustic ◽  
Large Growth ◽  
General Dispersion

The coupling of a large amplitude plasmon, generated by the beat-wave process, to ion acoustic waves may lead to modulational or decay instabilities, which are investigated here. A general dispersion relation obtainable from Zakharov equations predicts large growth rates (∼ωpi) for short wavelength modulations. To avoid these, extremely short pulse lengths are required in the beat-wave experiments. Due to the very long wavelength of the beat-plasmon, the decay instability is not likely below the ke V-temperatures.

Dynamics of nonlinear ion-acoustic waves in an external magnetic field

1985 ◽  
Vol 44 (8) ◽  
pp. 537-543 ◽  
Author(s):  
E. Infeld ◽  
P. Frycz ◽  
T. Czerwiśka-Lenkowska
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

The frequency and damping of ion-acoustic waves

1980 ◽  
Vol 58 (4) ◽  
pp. 565-568 ◽  
Author(s):  
A. J. Barnard ◽  
C. Gulizia
Keyword(s):  
Dispersion Relation ◽  
Electron Temperature ◽  
Acoustic Waves ◽  
Ion Temperature ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

The dispersion relation for a plasma with different ion and electron temperatures is solved numerically to obtain the frequency and the damping constant for ion-acoustic waves as a function of the wavenumber. It is shown that the commonly used expressions for these variables only apply if the parameter T = ziTe/Ti is larger than 20, and can lead to large errors if T is close to 1. (Here z1 is the ion charge, Te is the electron temperature, and Ti the ion temperature.) Tables and graphs of the frequency and damping as functions of the wavenumber are given for different values of T.

Dispersion relation for ion-acoustic waves

1971 ◽  
Vol 19 (9) ◽  
pp. 1188-1191 ◽  
Author(s):  
M.M. Abbas ◽  
F.B. Cooper
Keyword(s):  
Dispersion Relation ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

Stability of ion-acoustic solitons in a multispecies plasma consisting of non-isothermal electrons

1998 ◽  
Vol 60 (1) ◽  
pp. 151-158 ◽  
Author(s):  
DEBALINA CHAKRABORTY ◽  
K. P. DAS
Keyword(s):  
Acoustic Waves ◽  
Perturbation Expansion ◽  
Expansion Method ◽  
Ion Acoustic Waves ◽  
Long Wavelength ◽  
Petviashvili Equation ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
The Stability ◽  
Perturbation Expansion Method

A modified Kadomtsev–Petviashvili equation is derived for ion-acoustic waves in a multispecies plasma consisting of non-isothermal electrons. This equation is used to investigate the stability of modified KdV solitons against long-wavelength plane-wave perturbation using the small-k perturbation expansion method of Rowlands and Infeld. It is found that modified KdV solitons are stable.

Ion-acoustic wave instability driven by drifting electrons in a generalized Lorentzian distribution

1992 ◽  
Vol 47 (3) ◽  
pp. 445-464 ◽  
Author(s):  
Zhaoyue Meng ◽  
Richard M. Thorne ◽  
Danny Summers
Keyword(s):  
Electron Temperature ◽  
Acoustic Waves ◽  
Debye Length ◽  
High Energy ◽  
Dispersion Function ◽  
Electron Drift ◽  
Kappa Distribution ◽  
Ion Acoustic Waves ◽  
High Energy Tail ◽  
Ion Acoustic

A generalized Lorentzian (kappa) particle distribution function is useful for modelling plasma distributions with a high-energy tail that typically occur in space. The modified plasma dispersion function is employed to study the instability of ion-acoustic waves driven by electron drift in a hot isotropic unmagnetized plasma modelled by a kappa distribution. The real and imaginary parts of the wave frequency ω0 + ιγ are obtained as functions of the normalized wavenumber kλD, where λD is the electron Debye length. Marginal stability conditions for instability are obtained for different ion-to-electron temperature ratios. The results for a kappa distribution are compared with the classical results for a Maxwellian. In all cases studied the ion-acoustic waves are strongly damped at short wavelengths, kλD ≫ 1, but they can be destabilized at long wavelengths. The instability for both the kappa and Maxwellian distributions can be quenched by increasing the ion-electron temperature ratio Ti/Te. However, both the marginally unstable electron drift velocities and the growth rates of unstable waves can differ significantly between a generalized Lorentzian and a Maxwellian plasma; these differences are also influenced by the value of Ti/Te.

Self-focusing of nonlinear ion-acoustic waves and solitons in magnetized plasmas. Part 2. Numerical simulations, two-soliton collisions

1987 ◽  
Vol 37 (1) ◽  
pp. 97-106 ◽  
Author(s):  
E. Infeld ◽  
P. Frycz
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Growth Rates ◽  
Nonlinear Waves ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Self Focusing ◽  
Long Wave ◽  
Ion Acoustic ◽  
Soliton Collisions

Nonlinear waves and solitons satisfying the Zakharov-Kuznetsov equation for a dilute plasma immersed in a strong magnetic field are studied numerically. Growth rates of perpendicular instabilities, found theoretically in part 1, are confirmed and extended to arbitrary wavelengths of the perturbations (the calculations of part 1 were limited to long-wave perturbations). The effects of instabilities on nonlinear waves and solitons are illustrated graphically. Pre-vious, approximate results of other authors on the perpendicular growth rates for solitons are improved on. Similar results for perturbed nonlinear waves are presented. The effects of two-soliton collisions on instabilities are investigated. Rather surprisingly, we find that the growth of instabilities can be retarded by collisions. Instabilities can also be transferred from one soliton to another in a collision. This paper can be read independently of part 1.

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