Buildup of oscillations in twomode gyrotron
Abstract
Power gyrotrons with evolution of the interaction space are considered for generating stable singlemode oscillations under conditions favoring selfexcitation of several modes. Interaction of two modes, occurring in small resonator cavities, can be treated as a suppression of the mode with a smaller initial increment than that with a larger initial increment and as a nonlinear excitation of the second mode after excitation of the first mode acting as a primer. The attendant transient processes in a twomode gyrotron are described by a selfconsistent system of equations including a short equation of motion for electrons in an external magnetic field and in the field of two modes as well as equation of mode excitation, the same equation for both modes. These equations are supplemented with an integral expression for mode excitation by an electron beam. Numerical analysis of this system for two modes having Gaussian longitudinal profiles and resonating at the fundamental gyrofrequency or at its multiple confirm that both mechanisms stabilize singlemode oscillation under efficiencyoptimum conditions and also that stable twomode oscillation is possible.
 Publication:

USSR Rept Electron Elec Eng JPRS UEE
 Pub Date:
 September 1984
 Bibcode:
 1984RpEEE.......46Z
 Keywords:

 Cyclotron Resonance Devices;
 Modes;
 Self Excitation;
 Stable Oscillations;
 Electron Beams;
 Equations Of Motion;
 Numerical Analysis;
 Self Consistent Fields;
 Instrumentation and Photography