Whistlers in magnetoactive plasma. I

The whistler-band radiation of the ring electric current in a magnetoactive plasma is investigated. Particular attention is devoted to the variation of the distribution of radiated power over the spectrum of excited waves (plasma waves, conical-refraction waves, and whistlers) with variation of the radiator parameters. It is established that under nearly ionospheric conditions over a wide range of ring radii, most of the radiation power goes to conical-refraction waves. It is shown that allowance for current nonuniformity along the ring is of fundamental importance and can, in particular, lead to a substantial increase in the relative contribution of plasma waves.Scientific-Research Radio-Physics Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 9, pp. 990–1000, September, 1991.     

Transmission of microwaves through magnetoactive plasma

The possibility of transmission of microwaves through the plasma layer with an electron concentration of more than critical value is considered. The problem is solved by consideration of the interaction of a microwave with the plane layer of magnetoactive plasma. The problem is formulated by such a way as to obtain the estimation of the greatest lower bound of microwave transmission coefficient through the plasma layer. The results of numerical parametric investigations are applied for the transparency conditions of the shock wave plasma in space communication. The possibility of stable (without interruptions) microwave communication through the shock wave plasma is demonstrated     

Electromagnetically induced transparency in high-temperature magnetoactive plasma

We investigate a classical analog of electromagnetically induced transparency (EIT) currently popular in quantum electronics. We consider EIT for electron cyclotron waves in finite-temperature plasma. We derive an expression for the effective refractive index of an electromagnetic wave and study the dispersion and absorption of this wave under EIT conditions. Allowance for thermal motion is shown to radically change the behavior of the dispersion curves for the signal wave in the EIT region compared to the case of cold plasma.     

Low-frequency current instabilities in nonisothermal magnetoactive plasma

The excitation of current instabilities in the lower ionosphere is studied for magnetic-field-aligned inhomogeneities of arbitrary length with allowance for electron-temperature perturbations and the dependence of electron collision frequency on electron temperature. It is found that the threshold velocity of Farley-Buneman instability has a minimum for a finite degree of inhomogeneity elongation when the temperature dependence of the electron collision frequency is sufficiently strong.Scientific-Research Radio-Physics Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 1, pp. 25–36, January, 1993.     

Nonpotential surface waves in magnetoactive plasma structures

Conclusions In this paper we have studied the dispersion characteristics of nonpotential surface waves in two- and three-layered magnetized wave-bearing structures. For the case of a vacuum cavity in an infinite plasma, we have obtained an analytic solution for the SW frequency in a regime which is highly nonpotential. We have shown that when the thickness of the plasma layer in a vacuum-plsma-vacuum waveguide is reduced, the dispersion changes its character.We have investigated numerically how magnetic fields, the radii of the cylinders, and the azimuthal wave number affect the LF and HF branches of the spectrum of surface waves.Khar'kov State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 6, pp. 639–645, June, 1991.     

Oscillation interaction in a nonequilibrium magnetoactive plasma

Kharkov State University: Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 31, No. 6, pp. 675–679, June, 1988.     

Electromagnetic waves in a magnetoactive fluctuating plasma

Radiophysics and Electronics Institute, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 32, No. 1, pp. 27–33, January, 1989.     

Propagation of electromagnetic waves in hot magnetoactive plasma

The paper derives the general form of the tensor of dielectric permittivity? _ij(ω,k), Eq. (15), of non-relativistic hot magnetoactive collisionless plasma taking into consideration the influence of spatial dispersion. The general form of the tensor? _ij(ω,k) is used to express the tensorε _ij(ω,k) in the region of weak and strong spatial dispersion and in some special cases. A general dispersion equation (30) is derived and an analysis is made of the waves propagating in hot magnetoactive plasma. The expressions derived are used to investigate the damping of a right-handed circularly polarized wave propagating in hot magnetoactive plasma in the direction of the magnetic field.     

Penetration of electromagnetic waves into magnetoactive plasma

Landau studied the longitudinal field penetration into a semi-bounded plasma considering specularly reflecting electrons at the boundary. Kurilko and Popov and then Gorman examined the same problem considering a fraction “p” of all incident electrons reflecting specularly and the remaining portion difusely. Lastly, Mason treated the same problem at length and gave solutions for specular and diffuse reflections. Here the penetration of transverse electromagnetic waves into magnetoactive semi-bounded plasma has been studied and the electric field for specular reflection of electrons is obtained.     

Generation of the second harmonic in inhomogeneous magnetoactive plasma

The paper deals with the experimental study of conditions under which the second harmonic of a strong electromagnetic wave generating a spatially inhomogeneous plasma originates and exists. The second harmonic was detected by means of a h.f. probe inside the plasma and by a horn antenna outside the plasma. It was found that the beginning of generation of a strong second harmonic signal inside the plasma coincides with the overcoming of an evanescent layer and the free passage of the right-hand circularly polarized wave (RHCP wave) into an inhomogeneous plasma. Dependences of the second harmonic amplitude on the static magnetic field and the gas pressure are given.The authors wish to thank Dr. S. S. Moiseyev from FTI of Academy USSR (Kharkov) for valuable discussions concerning mechanisms of the second harmonic generation in an inhomogeneous plasma [4, 6]. To Ph.D.V. Kopeck); the authors would like to expresstheir thanks for many valuable discussions and his interest.     

On the conductivity of a magnetoactive turbulent plasma

The problem of determining the effective conductivity tensor of a magnetoactive turbulent plasma is considered in the approximation of isolated particles. Additional gyrotropic terms are shown to appear in the conductivity tensor in the presence of mean, nonzero magnetic helicity. The dispersion of propagating electromagnetic waves changes, additional modes and additional rotation of the polarization plane appear, and the waves can be amplified. The properties acquired by a plasma with helicity are similar to those observed in chiral and bianisotropic electrodynamic media.     

Thermal and reactive nonequilibrium of magnetoactive plasma flows

Based on multifluid equations derived from the Boltzman equation under inclusion of ionization and recombination reactions, the following convective processes in magnetoactive plasma flows transverse to homogeneous magnetic fields are investigated:The build-up of the nonuniform plasma state, the intercomponent thermal nonequilibrium and the reactive nonequilibrium in dependence of the flow coordinate. Due to the complexity of the problem, a numerical approach is used, parallel to which an approximate analytical theory is developed.     

Stimulated raman scattering from plasma modes in magnetoactive semiconductors

Stimulated scattering off electron plasma mode is investigated analytically for the case when the pump wave is an intense circularly polarised electromagnetic wave propagating parallel to a homogeneous dc magnetic field in an isotropic semiconductor-plasma. The threshold electric field of the pump necessary for the stimulated Raman scattering and the growth rate of the parametrically unstable mode have been obtained for two cases (i)B ₀=0 and (ii) B₀ ≠ 0. It is seen that the magnetic field does not significantly affect the threshold electric field as well as the growth rate provided the cyclotron frequency is small compared to the frequency of the pump wave. The threshold conditions are also found to be insensitive to the electron thermal velocity.