Decay Instability of the Ion Acoustic Wave

1975 ◽  
Vol 53 (6) ◽  
pp. 657-665
Author(s):  
S. R. Seshadri
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Pump Wave ◽  
Plasma Oscillation ◽  
Electron Plasma ◽  
Electromagnetic Mode ◽  
Ion Acoustic Wave ◽  
Plasma Mode ◽  
Ion Plasma ◽  
Ion Acoustic

The parametric excitation of the longitudinal, plasma mode and the transverse, electromagnetic mode in a warm, uniform plasma is investigated for the case in which the pump wave is another electromagnetic mode. The three interacting waves are assumed to propagate in the same direction. The longitudinal mode has two branches, namely, the electron plasma mode and the ion plasma mode. The parametric coupling of the longitudinal and the transverse waves in the presence of the pump wave leads to instabilities of the interacting waves. Illustrative numerical results are presented for the parametric instabilities of the electron plasma oscillation which is a part of the electron plasma mode and those of the ion acoustic waves and the ion plasma oscillations which are parts of the ion plasma mode. The ion acoustic wave is efficiently excited when the pump and the idler wave frequencies are approximately equal to one and a half times the electron plasma frequency.

scholarly journals Ion-Acoustic Instabilities in a Multi-Ion Plasma

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Noble P. Abraham ◽  
Sijo Sebastian ◽  
G. Sreekala ◽  
R. Jayapal ◽  
C. P. Anilkumar ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Oxygen Ions ◽  
Ion Plasma ◽  
Thermal Spread ◽  
Ion Acoustic ◽  
Acoustic Instabilities ◽  
The Stability

We have, in this paper, studied the stability of the ion-acoustic wave in a plasma composed of hydrogen, positively and negatively charged oxygen ions, and electrons, which approximates very well the plasma environment around a comet. Modelling each cometary component (H+, O+, and O−) by a ring distribution, we find that ion-acoustic waves can be generated at frequencies comparable to the hydrogen ion plasma frequency. The dispersion relation has been solved both analytically and numerically. We find that the ratio of the ring speed (u⊥s) to the thermal spread (vts) modifies the dispersion characteristics of the ion-acoustic wave. The contrasting behaviour of the phase velocity of the ion-acoustic wave in the presence of O− ions for u⊥s>vts (and vice versa) can be used to detect the presence of negatively charged oxygen ions and also their thermalization.

Nonlinear interaction of slow Alfvén wave with ion acoustic wave and applications to space plasma

2013 ◽  
Vol 79 (5) ◽  
pp. 833-836 ◽  
Author(s):  
B. K. DAS ◽  
R. P. SHARMA ◽  
N. YADAV
Keyword(s):  
Acoustic Waves ◽  
Analytical Study ◽  
Pump Wave ◽  
Modulational Instability ◽  
Solar Wind Plasma ◽  
Alfven Wave ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Model Equations

AbstractThe paper is concerned with the analytical study of nonlinear coupling of slow Alfvén wave (SW) with ion acoustic waves (IAWs) in high-β and low-β plasmas. Here the pump wave (SW) number density gets perturbed in the presence of IAW. The model equations of IAW and SW turn out to be the modified Zakharov system of equations when the ponderomotive nonlinearities are incorporated in the IAW and SW dynamics. Growth rate of modulational instability has been calculated. The relevance of these investigations for solar wind plasma and solar coronal plasma has also been discussed.

scholarly journals Determination of the electron temperature in the modified ionosphere over HAARP using the HF pumped Stimulated Brillouin Scatter (SBS) emission lines

2009 ◽  
Vol 27 (12) ◽  
pp. 4409-4427 ◽  
Author(s):  
P. A. Bernhardt ◽  
C. A. Selcher ◽  
R. H. Lehmberg ◽  
S. Rodriguez ◽  
J. Thomason ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Acoustic Wave ◽  
Electric Fields ◽  
Pump Wave ◽  
Scattered Wave ◽  
Matching Condition ◽  
Ion Acoustic Wave ◽  
Matching Conditions ◽  
Ion Acoustic ◽  
Stimulated Brillouin

Abstract. An ordinary mode electromagnetic wave can decay into an ion acoustic wave and a scattered electromagnetic wave by a process called stimulated Brillouin scatter (SBS). The first detection of this process during ionospheric modification with high power radio waves was reported by Norin et al. (2009) using the HAARP transmitter in Alaska. Subsequent experiments have provided additional verification of this process and quantitative interpretation of the scattered wave frequency offsets to yield measurements of the electron temperatures in the heated ionosphere. Using the SBS technique, electron temperatures between 3000 and 4000 K were measured over the HAARP facility. The matching conditions for decay of the high frequency pump wave show that in addition to the production of an ion-acoustic wave, an electrostatic ion cyclotron wave may also be produced by the generalized SBS processes. Based on the matching condition theory, the first profiles of the scattered wave amplitude are produced using the stimulated Brillouin scatter (SBS) matching conditions. These profiles are consistent with maximum ionospheric interactions at the upper-hybrid resonance height and at a region just below the plasma resonance altitude where the pump wave electric fields reach their maximum values.

Plasma boundary motion and the ion-acoustic wave

1983 ◽  
Vol 30 (1) ◽  
pp. 133-151 ◽  
Author(s):  
N. St. J. Braithwaite ◽  
L. M. Wickens
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Plasma Boundary ◽  
Planar Geometry ◽  
Wave Form ◽  
Ion Acoustic Wave ◽  
Sheath Edge ◽  
Ion Acoustic ◽  
Characteristics Analysis ◽  
Voltage Wave

Ion-acoustic waves can be launched into plasmas by applying an oscillating voltage wave form to an electrode. The precise mechanism by which these waves are launched from such an electrode is not fully understood. The work described here examines the modelling of sheath edge motion in connexion with acoustic wave launching in both planar and spherical geometries. A novel demonstration of the applicability of the kinetic Bohm criterion is given by using the method of characteristics. A characteristics analysis is also used to show that an expanding, but decelerating, non-planar sheath can give rise to quasi-neutral compression-like features in a plasma. It is also shown that in planar geometry neither this kind of expansion, nor an oscillatory sheath motion, generates compression-like features.

Nonlinear ion acoustic wave in a pair-ion plasma in a uniform weak magnetic field

2015 ◽  
Vol 90 (4) ◽  
pp. 045604 ◽  
Author(s):  
Biplab Maity ◽  
Samiran Ghosh ◽  
R Bharuthram
Keyword(s):  
Magnetic Field ◽  
Acoustic Wave ◽  
Weak Magnetic Field ◽  
Ion Acoustic Wave ◽  
Ion Plasma ◽  
Ion Acoustic

Maximization in the damping rate of the ion acoustic wave in a two-ion plasma

1975 ◽  
Vol 18 (6) ◽  
pp. 651 ◽  
Author(s):  
Masaharu Nakamura ◽  
Masataka Ito ◽  
Yoshiharu Nakamura ◽  
Tomizo Itoh
Keyword(s):  
Acoustic Wave ◽  
Ion Acoustic Wave ◽  
Ion Plasma ◽  
Ion Acoustic ◽  
Damping Rate

scholarly journals Effect of Negative Ions on the Instability of Ion-acoustic Waves in a Relativistic Plasma

1997 ◽  
Vol 50 (2) ◽  
pp. 319 ◽  
Author(s):  
K. K. Mondal ◽  
S. N. Paul ◽  
A. Roychowdhury
Keyword(s):  
Dispersion Relation ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
Negative Ions ◽  
Ion Concentration ◽  
Negative Ion ◽  
Relativistic Velocity ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic

The dispersion relation of an ion-acoustic wave propagating through a collisionless, unmagnetised plasma, having warm isothermal electrons and cold positive and negative ions has been derived. It is seen that the ion-acoustic wave will be unstable in the presence of streaming of ions. Instability of the wave is graphically analysed for the plasma having (H+, O¯) ions, (H+, O2¯) ions, (H+, SF5¯) ions, (He+, Cl¯) ions and (Ar+, O¯) ions with different negative ion concentration and relativistic velocity.

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