Nonlinear theory of relativistic beam interaction with an anisotropic plasma

The results of the theoretical study of the relaxation of relativistic electron beam on the noncollinear (K(perpendicular) not equal to 0) waves in the magnetized plasma are presented. No assumption of the weak influence of the beam on the properties of the excited waves was made (this assumption, for the magnetized plasma being wrong at already low absolute magnitudes of the beam current). The linear stage of the high-current electron beam instability is studied. The physical mechanisms changing the instability parameters with the beam current increase are found. The nonlinear theory of the single-mode relaxation of the beam respective to the spatially-periodic perturbations in the unconfined plasma and of the stationary amplification of the monochromatic signal are developed. The peculiarities of the linear stage of the high-current beam instability are shown to be persistent in the nonlinear regime as well. An excitation process of the regular waves in the confined anisotropic plasma by the across flying beam is studied. The beam relaxation time may increase as the beam current increases. The beam energy and current dependence of the beam kinetic energy into the mocrowave field energy conversion is discussed