scholarly journals Influence of Inhomogeneity on Transformation and Radiation Processes in Plasma with Upper Hybrid Pump

2019 ◽  
Vol 64 (9) ◽  
pp. 814
Author(s):  
V. G. Panchenko ◽  
P. V. Porytsky
Keyword(s):  
Pump Wave ◽  
Inhomogeneous Plasma ◽  
Parametric Instability ◽  
Langmuir Wave ◽  
Wave Transformation ◽  
Transformation Coefficient ◽  
Radiation Emission ◽  
Parametric Decay ◽  
Radiation Processes ◽  
Transverse Electromagnetic

On the basis of the kinetic theory of fluctuations, the processes of the longitudinal Langmuir wave transformation into a transverse electromagnetic wave in the turbulent inhomogeneous plasma have been studied. The plasma turbulence is assumed to arise owing to the parametric decay of the upper hybrid pump wave into a daughter wave and electron-drift oscillations. The transformation coefficient under the parametric instability saturation conditions is determined. The intensity of the electromagnetic radiation emission from the plasma is calculated, and its dependence on the plasma and pump wave parameters is found.

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.

Double Langmuir frequency radiation due to transformation processes in turbulent plasma

2014 ◽  
Vol 81 (2) ◽  
Author(s):  
V. N. Pavlenko ◽  
V. G. Panchenko ◽  
N. A. Beloshenko
Keyword(s):  
Pump Wave ◽  
Langmuir Wave ◽  
Transformation Process ◽  
Turbulent Plasma ◽  
Sound Waves ◽  
Double Electron ◽  
Langmuir Frequency ◽  
Transverse Electromagnetic ◽  
Transformation Processes ◽  
Frequency Radiation

We investigate the transformation process of longitudinal Langmuir wave into the transverse electromagnetic wave in turbulent plasma subjected to an upper hybrid pump. The case, when upper hybrid pump wave decays into daughter and ion – sound waves is considered. The transformation of the Langmuir wave into electromagnetic one is considered as the possible mechanism of energy radiation from the plasma. It is shown that the frequency of such radiation is chosen to be near double electron Langmuir frequency 2ωpe. These results give us the possibility to explain the nature of radiation from the laboratory and cosmic plasmas (particularly, from the solar crown).

Scattering of electromagnetic waves in a magnetized plasma with an HF pump

2002 ◽  
Vol 67 (5) ◽  
pp. 309-320 ◽  
Author(s):  
V. N. PAVLENKO ◽  
V. G. PANCHENKO ◽  
S. A. NAZARENKO
Keyword(s):  
Cross Sections ◽  
Electromagnetic Waves ◽  
Pump Wave ◽  
Parametric Instability ◽  
Density Fluctuations ◽  
Magnetized Plasma ◽  
Lower Hybrid ◽  
Ion Temperature ◽  
Temperature Anisotropy ◽  
Transverse Electromagnetic

The scattering of transverse electromagnetic waves by turbulent density fluctuations in a magnetized plasma in the presence of external pump fields is investigated. The case where a lower-hybrid pump wave decays into daughter and ion-cyclotron waves in a plasma with ion-temperature anisotropy is considered. The situation where an upper-hybrid pump wave parametrically excites modified convective cells and electron drift waves is also analyzed. The differential scattering cross-sections in the region above the parametric instability thresholds for these three cases are calculated.

Temperature relaxation in a parametrically unstable inhomogeneous plasma

2000 ◽  
Vol 64 (3) ◽  
pp. 205-210 ◽  
Author(s):  
V. G. PANCHENKO
Keyword(s):  
Relaxation Time ◽  
Relaxation Process ◽  
Pump Wave ◽  
Inhomogeneous Plasma ◽  
Parametric Instability ◽  
Drift Waves ◽  
Lower Hybrid ◽  
Electron Drift ◽  
Inverse Relaxation Time ◽  
Temperature Relaxation

On the basis of kinetic fluctuation theory, the relaxation process between the electron and ion temperatures in a magnetized inhomogeneous plasma is considered when an external pump wave parametrically decays into lower-hybrid and electron drift waves. In the region above the instability threshold, the inverse relaxation time is calculated, and its dependence on the density gradient and the pump-wave intensity and frequency is obtained. It is shown that the presence of the parametric instability leads to a decrease of the relaxation time.

Parametric decay instability of an inhomogeneous plasma in a frequency-modulated pump wave

2000 ◽  
Vol 26 (4) ◽  
pp. 314-319 ◽  
Author(s):  
V. I. Arkhipenko ◽  
V. N. Budnikov ◽  
E. Z. Gusakov ◽  
A. K. Kapanik ◽  
V. A. Pisarev ◽  
...  
Keyword(s):  
Pump Wave ◽  
Inhomogeneous Plasma ◽  
Decay Instability ◽  
Parametric Decay ◽  
Parametric Decay Instability

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.

Particle acceleration by a non-linear langmuir wave in an inhomogeneous plasma

1975 ◽  
Vol 53 (1) ◽  
pp. 101-102 ◽  
Author(s):  
V.I Karpman ◽  
J.N Istomin ◽  
D.R Shklyar
Keyword(s):  
Particle Acceleration ◽  
Inhomogeneous Plasma ◽  
Langmuir Wave ◽  
Non Linear

Decay Instability of an Electromagnetic Wave Incident on a Weakly-Inhomogeneous Magnetised Plasma

1982 ◽  
Vol 37 (2) ◽  
pp. 97-101
Author(s):  
Bhimsen K. Shivamoggi
Keyword(s):  
Electromagnetic Wave ◽  
Pump Wave ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Density Perturbation ◽  
Threshold Value ◽  
Wave Incident ◽  
Ion Acoustic Wave ◽  
Decay Instability ◽  
Electromagnetic Wave Incident

Abstract This paper considers the parametric decay of an electromagnetic wave incident on a weakly-inhomogeneous magnetised plasma into a Langmuir wave and an ion-acoustic wave. The Vlasov model is used in order to calculate the low-frequency electron-density perturbation produced by the beating of the side-band modes with the pump wave. The results show that the threshold value of the pump wave to undergo a decay instability drops in the presence of an inhomogeneity in the plasma.

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.

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