Laboratory modeling of nonlinear interaction of Langmuir waves with a magnetoplasma

We present the results of laboratory modeling of the physical processes which lead to smallscale stratification of the ionospheric plasma during active experiments on modification of the ionosphere by high-power radio waves. It is shown that such a stratification can result from thermal self-channeling of Langmuir waves in a magnetoplasma. We established that the selfchanneling is threshold in behavior such that the threshold significantly increases near gyroharmonics. It is demonstrated that in the process of self-channeling, the frequency spectrum of the Langmuir wave is enriched. In particular, spectral maxima are formed, which are shifted away from the carrier frequency by a value of the order of the lower-hybrid frequency. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 11, pp. 988–1003, November 2008.