On the limit state of wave — intensive beam in plasma medium

This paper examines the wave-beam state in an infinite electron plasma at the stage when the particles are captured by the wave and undergo phase mixing. The state of the beam is described by nonlinear selfcongruent equations, the plasma remains a linear, dispersing medium. Estimates are obtained, characterizing the redistribution of the energy of the initial beam at single-mode generation of the longitudinal field by a low-density relativistic electron beam. The maximum generation efficiency amounts to 10% and is attained for nonrelativistic beams at(n$_{0}$/n$_{p}$)$^{1/3}$ ≅0,5, where n$_{0,p}$ are the beam and plasma densities. The u p и, p heating effectiveness at this stage is estimated. A comparison withresults of numerical experiments is performed.