Modeling studies of nonlinear interaction of non-stationary high-power electromagnetic waves with the ionospheric plasma

Author(s):  
K.P. Garmash
1963 ◽  
Vol 41 (10) ◽  
pp. 1702-1711 ◽  
Author(s):  
Mahendra Singh Sodha ◽  
Carl J. Palumbo

In this communication the authors have obtained an expression for current density in a slightly ionized uniform plasma in the presence of a number of electric fields of different frequencies by solving the appropriate Boltzmann's equation. This expression along with the wave equation has been used to investigate the nonlinear mutual interaction of a number of electromagnetic waves, propagating in a plasma. Limitations of the present analysis have also been indicated and the physical significance of the results has been discussed. The technique has also been applied to investigate the mutual interaction of amplitude-modulated waves, and the results express a generalization of Luxembourg effect to a number of strong modulated waves.


Author(s):  
P. Maryam ◽  
Rozina Chaudhary ◽  
Shahid Ali ◽  
Hassan Amir Shah ◽  
Stefaan Poedts

Abstract Within the framework of kinetic theory, the nonlinear interaction of electromagnetic waves (EMWs) with a degenerate electron-ion plasma is studied to account for the electron quantum mechanical effects. For this purpose, a specific quantum regime is considered, for which the degenerate electron Fermi velocity is assumed to be taken of the order of group velocity of EMWs. This eventually leads to the existence of nonlinear Landau damping rate for the EMWs in the presence of electron Ponderomotive force. The electrons-ion density oscillations may be arisen from the nonlinear interaction of EMWs, leading to a new type of nonlinear Schrödinger equation in terms of a complex amplitude for electromagnetic pump wave. The profiles of nonlinear damping rate reveal that EMWs become less damped for increasing the quantum tunnelling effects. The electrostatic response for the linear electrostatic waves is also investigated and derived a linear dispersion for the ion-acoustic damping rate. The latter is a direct function of electron Fermi speed and does not rely on the Bohm tunneling effect. The obtained results are numerically analyzed for the two microwaves of different harmonics in the context of nonrelativistic astrophysical dense plasma environments, e.g., white dwarfs, where the electron quantum corrections cannot be ignored.


Author(s):  
V.V. Komarov ◽  
S.K. Bushanskiy ◽  
A.O. Churkin

Waveguide and cavity microwave filters continue to be the most important components of high-power radio electronic systems. Cavity microwave filters are of great interest as a separate group of devices of this type. The fields of application of such filters are constantly expanding, and the variety of their design is quite large. In addition, the requirements for their electromagnetic characteristics and reliability are currently increasing. In this regard, it becomes necessary to analyze the already created designs of these devices and study the main trends of their improvement. The objective of the present study is to review the known technical solutions of bandpass filters, made on cavity resonators of the microwave range. An overview of the designs of devices for filtering electromagnetic waves on cavity resonators with coaxial and waveguide coupling elements of various frequency ranges is carried out. It is proposed to use the configuration of basic resonators as the main criterion for the classification of these devices. In accordance with this criterion, five groups of filters are considered: on rectangular, cylindrical, spherical, coaxial resonators, as well as on resonators of complex shape. The review makes it possible to analyze the features of the implementation of different technical solutions for bandpass microwave filters of medium and high power levels and to identify the main trends in the development of this area of research.


2010 ◽  
Vol 28 (4) ◽  
pp. 531-537 ◽  
Author(s):  
R.P. Sharma ◽  
A. Monika ◽  
P. Sharma ◽  
P. Chauhan ◽  
A. Ji

AbstractThis paper presents an investigation of the excitation of a Tera hertz (THz) radiation by nonlinear interaction of a circularly polarized high power laser beam and density ripple in collisionless magneto plasma. The ponderomotive force due to the nonlinear interaction between the laser and density ripple generates a nonlinear current at a difference frequency. If the appropriate phase matching conditions are satisfied and the frequency of the ripple is appropriate, then this difference frequency can be brought in the THz range. Filamentation (self focusing) of a circularly polarized beam propagating along the direction of ambient magnetic field in plasma is first investigated within paraxial ray approximation. The beam gets focused when the initial power of the laser beam is greater than its critical power. Resulting localized beam couples with the pre-existing density ripple to produce a nonlinear current driving the THz radiation. Analytical expressions for the beam width of the laser beam, electric vector of the THz wave have been obtained. By changing the strength of the magnetic field, one can enhance or suppress the THz emission. For typical laser beam and plasma parameters with the incident laser power flux = 1014 W/cm2, laser beam radius (r0) = 40 µm, laser frequency (ω0) = 1014 rad/s and plasma density (n0) = 3 × 1018 cm−3, normalized ripple density amplitude (μ) = 0.3, the produced THz emission can be at the level of Giga watt in power.


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