Fast electrons and parametric excitation of a fast magnetosonic wave in a plasma

A detailed comparison is made of the theoretical and experimental results on the parametric turbulence due to decay excitation of a fast magnetosonic wave and a wave at the lower hybrid resonance in a magnetized plasma. It is shown that all the experimentally observed effects(the instability threshold, the typical wave numbers of the excited waves, the growth rate of the instability, the time evolution of this growth rate, the number and energy distribution of the resulting fast electrons, and the steady-state amplitude of the low-frequency waves) can be explained on the basis of the theory of parametric resonance in a plasma taking into account the finite pump wavelength and the quasilinear theory of parametric turbulence. The theoretical and experimental results are in good qualitative and quantitative agreement.