Stimulated Raman backscattering in a magnetized plasma

1978 ◽  
Vol 19 (2) ◽  
pp. 313-324 ◽  
Author(s):  
Joseph E. Willett ◽  
Behrooz Maraghechi
Keyword(s):  
Cold Plasma ◽  
Pump Wave ◽  
Electron Plasma ◽  
Magnetized Plasma ◽  
Threshold Power ◽  
Pump Frequency ◽  
Electron Plasma Wave ◽  
Parametric Decay ◽  
Electromagnetic Pump ◽  
Stimulated Raman Backscattering

The parametric decay of an intense electromagnetic (pump) wave into a back-scattered electromagnetic wave and an electron plasma wave is considered. The dispersion relation for a homogeneous magnetized plasma in the presence of the pump wave is developed in the cold-plasma approximation with the pump frequency large compared to the cyclotron and plasma frequencies. Formulae are derived for the growth rate γ and threshold power PT associated with the instability. The effects of the magnitude and direction of the static magnetic field on γ and PT are studied numerically.

scholarly journals Parametric Instabilities in a Magnetized and Collisional Plasma

1980 ◽  
Vol 33 (3) ◽  
pp. 531
Author(s):  
DR Phalswal ◽  
Anil Dube
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Pump Wave ◽  
Threshold Power ◽  
Pump Frequency ◽  
Electron Plasma Wave ◽  
Hot Plasma ◽  
Damping Rate ◽  
Free Electron Plasma ◽  
The Magnetic Field

The dispersion relation for a magnetized, collisional and hot plasma in the presence of a pump wave is developed for the case where the pump frequency Wo is large compared with the cyclotron frequency Wc and the plasma frequency Wp. Formulae for the growth rate, the damping rate for the free electron plasma wave and the threshold power are derived and discussed numerically under different conditions. It is found that in a hot plasma (for magnetic fields with wc/wp = 1 and 10) the threshold power PT is less than or greater than that in a cold plasma for the (Rew2)+ or (Rewz)_ modes respectively. In a weak magnetic field (wc/wp = 0�1), PT does not vary with the direction B of the magnetic field or the (Rewz)+ mode. However, PT for the (Rewz)_ mode is a minimum at B = 30� and 10� for c/wp = 1 and 10 respectively, and it becomes very large (105-107 times its value in a cold unmagnetized lasma) for wc/wp = 0�1. The results for the growth rate are found to be just the reverse of hose for the threshold power.

Scattering of electromagnetic waves by anomalous fluctuations of a magnetized plasma

1990 ◽  
Vol 43 (2) ◽  
pp. 165-172 ◽  
Author(s):  
V. N. Pavlenko ◽  
V. G. Panchenko
Keyword(s):  
Cross Section ◽  
Electromagnetic Waves ◽  
Pump Wave ◽  
Density Fluctuations ◽  
Scattering Cross Section ◽  
Magnetized Plasma ◽  
Lower Hybrid ◽  
Scattering Cross ◽  
Parametric Decay ◽  
Ion Acoustic

Fluctuations and scattering of transverse electromagnetic waves by density fluctuations in a magnetized plasma in the presence of parametric decay of the pump wave are investigated. The spectral density of electron-density fluctuations is calculated. It is shown that the differential scattering cross-section has sharp maxima at the ion-acoustic and lower-hybrid frequencies when parametric decay of the lower-hybrid pump wave occurs. We note that scattering at the ion-acoustic frequency is dominant. When the pump-wave amplitude tends to the threshold strength of the electric field the scattering cross-section increases anomalously, i.e. there is critical opalescence.

Decay instability of cirularly polarized waves into cirularly polarized and Langmuir waves in a magnetized plasma

1974 ◽  
Vol 11 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Kai Fong Lee
Keyword(s):  
Pump Wave ◽  
Parametric Instability ◽  
Perturbation Expansion ◽  
Langmuir Wave ◽  
Magnetized Plasma ◽  
Multiple Time ◽  
Langmuir Waves ◽  
Left Hand ◽  
Electromagnetic Pump ◽  
Polarized Waves

A study is made of a parametric instability in a magnetized plasma in which an electromagnetic pump wave of either right- or left-hand circular polarization decays into a Langmuir wave and another circularly polarized wave, all with wave vectors colinear with the external magnetic field. The analysis is based on a multiple-time-scale perturbation expansion of the fluid equations, incorporating the effects of temperature, collisions, and the spatial variation of the pump wave. The threshold values of the pump field intensity required for instability and the growth rates above threshold are calculated.

Parametric decay in a two-electron-temperature plasma

1990 ◽  
Vol 43 (3) ◽  
pp. 451-456
Author(s):  
S. Guha ◽  
Meenu Asthana
Keyword(s):  
Growth Rate ◽  
Dispersion Relation ◽  
Electron Temperature ◽  
Pump Wave ◽  
Nonlinear Dispersion ◽  
Hybrid Wave ◽  
Temperature Plasma ◽  
Parametric Decay ◽  
Electromagnetic Pump ◽  
Nonlinear Dispersion Relation

Nonlinear decay of an ordinary electromagnetic pump wave into an electro-acoustic wave and an upper-hybrid wave in a two-electron-temperature plasma has been investigated analytically. In contrast with the work of Sharma, Ramamurthy & Yu (1984), it is found that the decay can take place in the absence of the restrictive condition Ti ≫ Te and the plasma be magnetized. Using a hydrodynamical model of the plasma, the nonlinear dispersion relation and growth rate are obtained. A comparison of the present investigation is made with earlier work, and its possible application to the ELMO bumpy torus is discussed.

scholarly journals Parametric Instabilities in a Magnetized Plasma

1982 ◽  
Vol 35 (4) ◽  
pp. 409
Author(s):  
Bhimsen K Shivamoggi
Keyword(s):  
Magnetic Field ◽  
Pump Wave ◽  
Stimulated Raman Scattering ◽  
Brillouin Scattering ◽  
Magnetized Plasma ◽  
Stimulated Scattering ◽  
Electromagnetic Pump ◽  
Background Magnetic Field ◽  
Parametric Instabilities ◽  
Stimulated Brillouin

This paper makes a study of stimulated Raman scattering and stimulated Brillouin scattering of an incident electromagnetic pump wave in a magnetized plasma. The background magnetic field is taken to be parallel to the pump electric field. The growth rates of the two stimulated-scattering instabilities are found to be reduced in the presence of the background magnetic field.

Scattering from electron density irregularities in a compressible anisotropic plasma

1980 ◽  
Vol 24 (2) ◽  
pp. 341-358 ◽  
Author(s):  
T. Okuzawa ◽  
T. H. Nguyen
Keyword(s):  
Electron Density ◽  
Wave Scattering ◽  
Cold Plasma ◽  
Mode Conversion ◽  
Electron Plasma ◽  
Anisotropic Plasma ◽  
Scattered Electron ◽  
Electron Plasma Wave ◽  
Random Fluctuations ◽  
Electron Density Irregularities

The cold-plasma model of the radio wave scattering from spatially random fluctuations of electron density in an anisotropic plasma is extended to the warmplasma model, in which the effect of electron pressure is taken into account. Since the medium is compressible as well as anisotropic, there is the additional possibility of mode conversion from an incident electromagnetic wave to a scattered electron plasma wave. Some numerical results are also included.

Parametric Decay Processes and Heating in a Bounded Magnetized Plasma

1977 ◽  
pp. 377-394 ◽  
Author(s):  
G. van Oost ◽  
V. P. Bhatnagar ◽  
A. M. Messiaen ◽  
A. S. Paithanker ◽  
P. E. Vandenplas
Keyword(s):  
Magnetized Plasma ◽  
Parametric Decay

Decay of electron plasma waves into other electron plasma wave modes

1971 ◽  
Vol 36 (6) ◽  
pp. 473-474 ◽  
Author(s):  
R.N. Franklin ◽  
G.J. Smith ◽  
S.M. Hamberger ◽  
G. Lampis
Keyword(s):  
Plasma Wave ◽  
Plasma Waves ◽  
Electron Plasma ◽  
Electron Plasma Wave ◽  
Wave Modes
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