Non-linear r.f. heating of ionospheric plasma
TL;DR: In this paper, the nonlinear heating of electrons in the ionospheric plasma due to high-power radio wave propagation was investigated through an integro-differential equation derived from Boltzmann velocity-moment equations.
Abstract: The non-linear heating of electrons in the ionospheric plasma due to high-power radio wave propagation has been investigated through an integro-differential equation derived from Boltzmann velocity-moment equations. Various processes appropriate to the situation under study are taken into account. The numerical solution of the derived equation is presented graphically.
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TL;DR: In this paper, a unified ionospheric electron collision frequency model profile was calculated in the height range 50-500 km and the computed profile accounts for the electron collisions with the neutral particles as well as the ions.
54 citations
TL;DR: In this paper, a quasi-steady state solution for a homogeneous plasma undergoing simultaneous ionization and rotation in a crossed electric magnetic field was obtained for a cross-magnetic field.
Abstract: A quasi‐steady state solution has been obtained for a homogeneous plasma undergoing simultaneous ionization and rotation in a crossed electric‐magnetic field. It was found that the ordinary electron‐impact ionization process, when supported by the full rate of energy transfer from the ions to the electrons via Coulomb collisions, will be sufficiently rapid to provide a close coupling between the kinetic energy of the ions and the ionization energy of the neutrals under a wide range of conditions. The results can be used to interpret the limiting velocity observed by Alfven and Fahleson in some recent rotating plasma experiments. The same results can also be used to predict the occurrence of similar limiting velocity in some rectilinear plasma accelerators.
26 citations
TL;DR: In this paper, a one-dimensional inhomogeneous model is used to describe the nonlinear interaction of a radiofrequency plane wave with a time-varying plasma medium.
Abstract: A one-dimensional, inhomogeneous model is used to describe the nonlinear interaction of a radio-frequency plane wave with a time-varying plasma medium. A monochromatic plane wave is normally incident upon an electron density profile where the electron density gradients are shallow compared to a wavelength. Changes in electron temperature and electron density are induced which continually alter the pattern of electromagnetic energy deposition into the medium. The electron energy relaxation time is much longer than the period of the electromagnetic wave, so that the electron temperature does not follow the rapid variations in the impressed field. A nonlinear constitutive relationship is derived relating the macroscopic current density to the impressed electric vector, assuming that the wave field is almost monochromatic in the medium. The time-dependent response of the plasma medium may be found by numerically solving the energy-balance equations and the continuity equation for the electron gas. The spread ...
16 citations
TL;DR: In this paper, a unique wave interaction experiment employing the Arecibo 2.0-MW, 430-MHz radar as disturbing or heating transmitter has been performed, where the heater beam used was much smaller in angular extent than the probing or wanted beam, yielding an unfavorable geometric weighting factor and making the experiment very sensitive to reflection properties of the E region.
Abstract: A unique wave interaction experiment employing the Arecibo 2.0-MW, 430-MHz radar as disturbing or heating transmitter has been performed. The purpose of this experiment was to evaluate UHF electron heating effects and to extend the wave interaction technique to higher than usual heights (˜100 km). The heater beam used was much smaller in angular extent than the probing or wanted beam, yielding an unfavorable geometric weighting factor and making the experiment very sensitive to reflection properties of the E region. Nonetheless, wave interaction was easily detected using a completely digital signal processing technique. Comparison of experimental wave interaction results with a numerical model of the process indicates that lower thermosphere electron cooling rates are possibly too small by a factor of 4. Power spectra of the 3.155 MHz wanted signal (reflected from E region) amplitude fluctuations for ‘quiet’ and ‘disturbed’ days are also given.
11 citations
9 citations