Theory of stimulated scattering of large-amplitude waves

1995 ◽  
Vol 53 (2) ◽  
pp. 213-222 ◽  
Author(s):  
L. Stenflo
Keyword(s):  
Dispersion Relation ◽  
Large Amplitude ◽  
Pump Wave ◽  
Low Frequency ◽  
Wave Frequency ◽  
Nonlinear Coupling ◽  
Stimulated Scattering ◽  
Pump Wave Frequency ◽  
General Dispersion ◽  
Electron Gyrofrequency

By means of the standard fluid equations, we consider the nonlinear coupling between a large-amplitude pump wave and the low-frequency modes in a collisional plasma. We derive the general dispersion relation in order to discuss the case where the pump-wave frequency is not much larger than the electron gyrofrequency.

Theory of stimulated scattering of large-amplitude waves

1999 ◽  
Vol 61 (1) ◽  
pp. 129-134 ◽  
Author(s):  
L. STENFLO
Keyword(s):  
Dispersion Relation ◽  
High Frequency ◽  
Large Amplitude ◽  
Pump Wave ◽  
Low Frequency ◽  
Nonlinear Dispersion ◽  
Stimulated Scattering ◽  
Nonlinear Dispersion Relation

A nonlinear dispersion relation that governs the interaction between a high-frequency pump wave and the low-frequency modes in a plasma is derived. Previous results are generalized and discussed.

scholarly journals Numerical simulations of a three-wave coupling occurring in the ionospheric plasma

2002 ◽  
Vol 9 (1) ◽  
pp. 1-10 ◽  
Author(s):  
H. Usui ◽  
H. Matsumoto ◽  
R. Gendrin
Keyword(s):  
Dispersion Relation ◽  
Ionospheric Plasma ◽  
Pump Wave ◽  
Low Frequency ◽  
Hybrid Wave ◽  
Local Electron ◽  
Coupling Condition ◽  
Langmuir Waves ◽  
Wave Coupling ◽  
Coupling Process

Abstract. We studied a three-wave coupling process occurring in an active experiment of microwave power transmission (MPT) in the ionospheric plasma by performing one-dimensional electromagnetic PIC (Particle-In-Cell) simulations. In order to examine the spatial variation of the coupling process, we continuously emitted intense electromagnetic waves from an antenna located at a simulation boundary. In the three-wave coupling, a low-frequency electrostatic wave is excited as the result of a nonlinear interaction between the forward propagating pump wave and backscattered wave. In the simulations, low-frequency electrostatic bursts are discontinuously observed in space. The discontinuity of the electrostatic bursts is accounted for by the local electron heating due to the bursts and the associated modification of the wave dispersion relation. In a case where the pump wave propagates along the geomagnetic field Bext , several bursts of Langmuir waves are observed. Since the first burst consumes a part of the pump wave energy, the pump wave is weakened and cannot trigger the three-wave coupling beyond the region where the burst occurs. Since the dispersion relation of the Langmuir wave is variable, due to the local electron heating by the burst, the coupling condition eventually becomes unsatisfied and the first interaction becomes weak. Another burst of Langmuir waves is observed at a different region beyond the location of the first burst. In the case of perpendicular propagation, the upper hybrid wave, one of the mode branches of the electron cyclotron harmonic waves, is excited. Since the dispersion relation of the upper hybrid wave is less sensitive to the electron temperature, the coupling condition is not easily violated by the temperature increase. As a result, the three-wave coupling periodically takes place in time and eventually, the transmission ratio of the microwaves becomes approximately 20%, while almost no attenuation of the pump waves is observed after the first electrostatic burst in the parallel case. We also examined the dependency of the temporal growth rate for the electrostatic waves on the amplitude of the pump wave.

Theory of stimulated scattering of large-amplitude waves

2000 ◽  
Vol 64 (4) ◽  
pp. 353-357 ◽  
Author(s):  
L. STENFLO ◽  
P. K. SHUKLA
Keyword(s):  
Growth Rates ◽  
High Frequency ◽  
Large Amplitude ◽  
Electromagnetic Waves ◽  
Long Term Evolution ◽  
Stimulated Scattering ◽  
Term Evolution ◽  
Laboratory Plasmas ◽  
General Dispersion

Comprehensive comments on the theory of stimulated scattering instabilities of high-frequency electromagnetic waves in magnetized plasmas are presented. It is shown that our general dispersion relations are appropriate for deducing valuable information regarding the growth rates of scattering instabilities and the long-term evolution of modulationally unstable waves in space and laboratory plasmas as well as in astrophysical settings.

scholarly journals General Dispersion Relation for Surface Waves on a Plasma?Vacuum Interface: Application to Magnetised Plasmas

1992 ◽  
Vol 45 (1) ◽  
pp. 55 ◽  
Author(s):  
GW Rowe
Keyword(s):  
Dispersion Relation ◽  
General Theory ◽  
Surface Waves ◽  
Low Frequency ◽  
Surface Currents ◽  
Ion Plasma ◽  
Vacuum Interface ◽  
Slight Extension ◽  
Infinite Conductivity ◽  
General Dispersion

The general dispersion relation for electromagnetic surface waves on a plasma-vacuum interface, recently derived by Rowe (1991), is applied to the case of a cold magnetised plasma bounded by a vacuum. It is illustrated how the dispersion relation and the surface wave fields may be determined in practice, and some general results are given. It is remarked that a plasma of this type satisfies the consistency conditions which were derived for the general theory by Rowe. These general results are then used to reproduce the dispersion relation of Cramer and Donnelly (1983) for low frequency surface waves in an electron-ion plasma. This example illustrates the general principles of the theory. A major difference between the derivation in their paper and the calculation of this paper is that in the former the plasma was assumed to be infinitely conducting whereas here the plasma is strictly assumed to have finite conductivity.The transition to infinite conductivity, which involves a slight extension of the general theory to include surface currents, is thus also discussed.

Stimulated radio emission of the ionospheric plasma at the second harmonic of the pump wave frequency

1986 ◽  
Vol 29 (1) ◽  
pp. 22-25 ◽  
Author(s):  
A. N. Karashtin ◽  
Yu. S. Korobkov ◽  
V. L. Frolov ◽  
M. Sh. Tsimring
Keyword(s):  
Radio Emission ◽  
Ionospheric Plasma ◽  
Pump Wave ◽  
Second Harmonic ◽  
Wave Frequency ◽  
Pump Wave Frequency
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