Competition of Oscillations at Different Cyclotron Harmonics in the Subterahertz Large-Orbit Gyrotron

Recently, 30-keV/0.7-A continuous wave (CW) subterahertz large-orbit gyrotron was experimentally realized. In this experiment, two different modes at different (second and third) cyclotron harmonics were excited in the same cavity separately at slightly different operating magnetic fields. This work is dedicated to description and theoretical explanation of various regimes of competition of these two modes observed in the experiment.