Parametric excitation in an inhomogeneous plasma

1971 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
C. S. Chen
Keyword(s):  
Electric Field ◽  
Parametric Excitation ◽  
Growth Rates ◽  
Inhomogeneous Plasma ◽  
Electron Plasma ◽  
Transverse Waves ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Oscillating Electric Field ◽  
Unmagnetized Plasma

An infinite, inhomogeneous electron plasma driven by a spatially uniform oscillating electric field is investigated. The multi-time perturbation method is used to analyze possible parametric excitations of transverse waves and to evaluate their growth rates. It is shown that there exist subharmonic excitations of: (1) a pair of transverse waves in an unmagnetized plasma and (2) a pair of one right and one left circularly polarized wave in a magnetoplasma. Additionally, parametric excitation of two right or two left circularly polarized waves with different frequencies can exist in a magnetoplasma. The subharmonic excitations are impossible whenever the density gradient and the applied electric field are perpendicular. However, parametric excitation is possible with all configurations.

Parametric excitation of a plasma

1970 ◽  
Vol 4 (2) ◽  
pp. 357-369 ◽  
Author(s):  
C. S. Chen ◽  
G. J. Lewak
Keyword(s):  
Growth Rate ◽  
Parametric Excitation ◽  
Langmuir Wave ◽  
Magnetized Plasma ◽  
Transverse Waves ◽  
Ion Motion ◽  
Oscillating Electric Field ◽  
Unmagnetized Plasma ◽  
The Magnetic Field ◽  
Transverse Propagation

The parametric effect of an applied uniform oscillating electric field on both unmagnetized and magnetized plasmas is investigated. By using a perturbation method of multitime scales, we have shown that parametric excitation of transverse waves propagating obliquely to the applied field in an unmagnetized plasma is possible. The growth rate of the excited waves reaches a maximum for transverse propagation. Ion motion does not change the character of the parametric excitation except by reducing the growth rate. In a magnetized plasma it is shown that excitation of a pair of waves is possible where one is a Langmuir wave, propagating along the magnetic field and the other is a circularly polarized transverse wave propagating in the opposite direction.

A polarization and band reconfigurable cross-slot antenna for multiband application

2019 ◽  
Vol 11 (10) ◽  
pp. 1054-1060
Author(s):  
Kapil Saraswat ◽  
A. R. Harish
Keyword(s):  
Electric Field ◽  
Ground Plane ◽  
Slot Antenna ◽  
Circularly Polarized ◽  
Design Concepts ◽  
Feed Line ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Microstrip Feed Line ◽  
Microstrip Feed

AbstractA polarization and band reconfigurable cross-slot antenna for multiband applications is presented in this paper. The antenna consists of four p–i–n diodes embedded in the cross-shaped slot in a ground plane and excited by a microstrip feed line. The p–i–n diodes are placed in such a way that they produce multiple bands, with linearly and circularly polarized (CP) radiation. By switching the states of the p–i–n diodes, the sense of rotation of the electric field in CP radiation can be reconfigured. The proposed structure can be configured to produce two bands that radiate linearly polarized waves or three bands, where, two are linearly polarized and one is CP. The proposed design concepts are validated bythe CST studio suite as well as measurementsare carried out on fabricated prototypes.

Waves in magnetoplasma with a stochastic magnetic field

1980 ◽  
Vol 23 (2) ◽  
pp. 311-320
Author(s):  
Y. S. Prahalad ◽  
M. L. Mittal
Keyword(s):  
Magnetic Field ◽  
Nonlinear Interaction ◽  
Linear Analysis ◽  
Coupling Coefficients ◽  
Transverse Waves ◽  
Circularly Polarized ◽  
Transverse Modes ◽  
Polarized Waves ◽  
Stochastic Magnetic Field ◽  
The Magnetic Field

In the present analysis, a normal mode approach is used to study waves in a plasma subjected to a spatially uniform but temporally stochastic magnetic field. The first part deals with the evolution of circularly polarized transverse waves. Making a linear analysis, it is shown that the coherent waves are damped. The nature of the damping is determined by the Kubo number. In the second part, the nonlinear interaction of three coherent waves propagating along the magnetic field is analyzed. The coupling coefficients for the interaction of two circularly polarized waves and a longitudinal one are calculated. It is shown that for coherent waves, the system is equivalent to the interaction of two damped transverse modes with an undamped longitudinal one.

Periodic, highly superluminous, nonlinear waves in a cold, unmagnetized plasma

1982 ◽  
Vol 27 (2) ◽  
pp. 267-276 ◽  
Author(s):  
P. C. Clemmow
Keyword(s):  
Perturbation Method ◽  
Nonlinear Waves ◽  
Small Amplitude ◽  
Plane Waves ◽  
Electron Plasma ◽  
Periodic Wave ◽  
Electric Vector ◽  
Third Wave ◽  
Transverse Waves ◽  
Unmagnetized Plasma

With respect to the propagation through a cold, unmagnetized, electron plasma of nonlinear, highly superluminous, plane waves of fixed profile, with electric vector in a fixed plane parallel to the direction of propagation, it is known that, in addition to the familiar longitudinal and quasi-transverse waves, there can also be a third periodic wave. The perturbation method by which this third wave has previously been analysed is of restricted validity, and fails to describe how the wave disappears in the approach to the small-amplitude limit, where the longitudinal and transverse waves alone survive.

scholarly journals Some Applications of Transformation to the Space?independent Frame in the Processes of Strong Radiation in Plasmas

1983 ◽  
Vol 36 (1) ◽  
pp. 67 ◽  
Author(s):  
SN PauI ◽  
B Chakraborty
Keyword(s):  
Dispersion Relation ◽  
Differential Equations ◽  
Cold Plasma ◽  
Nonlinear Differential Equations ◽  
Nonlinear Partial Differential Equations ◽  
Transverse Waves ◽  
Nonlinear Plasma ◽  
Circularly Polarized ◽  
Unmagnetized Plasma ◽  
Strong Radiation

Transformation of nonlinear plasma equations from a lab frame S to the space-independent frame S' (both inertial) for an electromagnetic (EM) wave in an unbounded plasma reduces the nonlinear partial differential equations in S to ordinary nonlinear differential equations in S'. This relativistically correct transformation is used (1) to find the intensity induced precessional rotation of the polarization ellipse of vibration of an EM wave, (2) in the S-frame Lagrangian of the particles and field produced by them to derive the exact nonlinearly correct dispersion relation for a strong circularly polarized wave in a cold unmagnetized plasma, and (3) to rectify some much discussed differential equations obtained by Akhiezer and Polovin (1956) to study the evolution of longitudinal and transverse waves in a cold plasma.

Anomalous absorption of the circularly polarized electromagnetic beams near the plasma frequency in a magnetized electron plasma

2007 ◽  
Vol 73 (3) ◽  
pp. 315-330 ◽  
Author(s):  
S. R. SESHADRI
Keyword(s):  
Resonant Frequency ◽  
Plasma Frequency ◽  
Unit Length ◽  
Plane Waves ◽  
Electron Plasma ◽  
Magnetostatic Field ◽  
Power Absorption ◽  
Circularly Polarized ◽  
Focused Beams ◽  
Electromagnetic Beams

AbstractThe propagation of circularly polarized electromagnetic beams along the magnetostatic field in an electron plasma is investigated. As a consequence of a strong interaction with the medium, the beam spreads rapidly on propagation near the cutoff frequencies and the cyclotron resonant frequency of the corresponding plane waves, as well as near the plasma frequency. The power absorption for unit length near the cyclotron frequency and the plasma frequency are determined. For tightly focused beams, there is significant power absorption near the plasma frequency as compared with that at the cyclotron resonant frequency.

Oscillating Electric Field Effects on Adsorption of the Methane–Water System on Kaolinite Surface

2018 ◽  
Vol 32 (11) ◽  
pp. 11440-11451 ◽  
Author(s):  
Yudou Wang ◽  
Bo Liao ◽  
Zhaoyang Kong ◽  
Zhigang Sun ◽  
Li Qiu ◽  
...  
Keyword(s):  
Electric Field ◽  
Water System ◽  
Electric Field Effects ◽  
Field Effects ◽  
Oscillating Electric Field ◽  
Kaolinite Surface

Parametric Side-Scattering by Waves Near the Hybrid Resonance Frequencies in Inhomogeneous Plasmas

1975 ◽  
Vol 30 (6-7) ◽  
pp. 911-912 ◽  
Author(s):  
P. K. Shukla ◽  
M. Y. Yu ◽  
K. H. Spatschek
Keyword(s):  
Growth Rates ◽  
Inhomogeneous Plasma ◽  
Lower Hybrid ◽  
Hybrid Resonance ◽  
Resonance Frequencies

Abstract The temporal growth rates are calculated for side-scat-tering of light by modes near the upper and lower hybrid frequencies in a turbulent, inhomogeneous plasma.

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