NONLINEAR EVOLUTIONARY PROCESSES IN A FREE-ELECTRON LASER GENERATOR OF DIFFRACTED RADIATION

Nonlinear evolutionary processes with two control parameters, one of w hich is related to the electrodynamic structure (positive feedback) an d the other is related to the constant electric field applied to the e lectron flux, are studied in a fi ee-electron laser, which is a diffra cted-radiation oscillator. To this end, first, the linear spectral pro blem for an open-cavity resonator is investigated and the dispersion r elation near the Morse critical point is established. Then the nonline ar evolutionary equation with two control parameters is constructed. A nalysis of the latter makes it possible to determine the properties of the parametric dependence of the bifurcation and structural stability , which are determined by small variations of the control parameter (t uning of the cavity). This explains the operating efficiency of a diff racted-radiation oscillator in the millimeter and submillimeter wavele ngth ranges. (C) 1997 American Institute of Physics.