Theory of gyrotron phase locked by resonant load

Stabilization of the gyrotron radiation frequency finds number of applications especially for plasma diagnostics. The gyrotron can be stabilised by a partial reflection from an external resonant load. For that, a quasi-optical cavity with a corrugated mirror can be implemented into the load, the nonresonant reflection being assumed sufficiently small. If the gyrotron operates at a mode with non-zero azimuthal index, a shallow Bragg corrugation of the output may be necessary to couple the reflected wave to the cavity mode and the quality factor (Q-factor) determines the stability against the self-consistent load frequency band from the phased reflections.