Mode Switching in a Gyrotron with Azimuthally Corrugated Resonator

Abstract

The operation of a gyrotron having a cylindrical resonator with an azimuthally corrugated wall is analyzed. In such a device, wall corrugation cancels the degeneracy of the modes with azimuthally standing patterns. The coupling between these modes depends on the radius of electron beam. It is shown that such a gyrotron can be easily switched from one mode to another. When the switching is done with the repetition frequency equal to the rotational frequency of magnetic islands, this sort of operation can be used for suppression of neoclassical tearing modes in large-scale tokamaks and stellarators.

Injection locking of a two-mode electron oscillator with close frequencies

“…In such a case, 12,14 except for some special cases considered in Ref. 7. Finally, after renormalization of time, t !…”

“…5,6 Also, a low-power external driving of a high-power oscillator may result in the fast frequency step tuning owing to the mode switching effect. [7][8][9] Nevertheless, the fundamentals of the mode switching are still poorly understood. In Refs.…”