Nonstationary processes in a diffraction-output orotron

The nonlinear dynamics of an orotron with diffraction output is studied. Th e evolution of the longitudinal field distribution is described by means of a parabolic equation subject to the condition of zero reflection at the co llector end of the interaction space. For stationary regimes, the regions o f high efficiency are delineated on the parameter plane, with the parameter s being the departure from the critical frequency and the reduced length of the interaction space. From numerical results, the parameter plane is divi ded into the regions of stationary operation, periodic self-modulation, and stochastic self-modulation. It is demonstrated that self-modulation oscill ating modes can be obtained most easily if the effective bounce frequency s lightly exceeds the cutoff frequency, with the former being the blinking fr equency of the dipole comprising an electron and its reflection in the regu larly corrugated slow-wave guide. (C) 2000 MAIK "Nauka/Interperiodica".