Nonlinear dynamics of resonant stimulated Cerenkov emission in a spatially bounded plasma

We discuss the nonlinear nonstationary problem of resonant Cerenkov radiation by a magnetized relativistic high-current electron beam with a front propagating in a transverse-uniform plasma waveguide of finite length. Using numerical simulation we demonstrate the existence of optimal values for the beam-plasma system parameters corresponding to maximum amplitude of the wave radiated at the output. When the optimal beam current is chosen, an almost steady value of the amplitude of the output radiation is observed. Further increases in the current destroy the steady state: the output radiation becomes chaotic, and the radiated power stops increasing. 26 refs., 3 figs., 1 tab