Stimulated scattering of a plasma wave by a relativistic electron beam

A theory is developed for the collective processes associated with the stimulated coherent scattering of a plasma wave that is obliquely incident on an electron beam. A system of nonlinear equations is obtained which describes changes in the amplitudes of the fields of the interacting waves and the motion of the beam electrons, which is assumed to be relativistic in the general case. The cases of electron beam scattering by the copropagating and counterpropagating plasma waves are examined, and the elementary mechanisms involved are identified. The possible mechanisms responsible for the saturation of scattering processes are investigated.