Phase-Locking of Second-Harmonic Gyrotrons for Providing MW-Level Output Power
Г. Г. Денисов, I. V. Zotova, I. V. Zheleznov, A. M. Malkin, N. S. Ginzburg, A. S. Sergeev, E. S. Semenov, M. Yu. Glyavin
Abstract
We propose the method of providing megawatt (MW)-level output power in continuous wave (CW) or long-pulse second-harmonic (SH) gyrotrons using phase-locking by a weak external monochromatic signal. Typically, the power of harmonic gyrotrons is hindered due to excitation of spurious fundamental-harmonic modes at the front of the accelerating voltage and the beam current. Injection of a seeding signal at the operating SH mode (priming) can suppress the spurious generation during the startup process. Within the frame of a self-consistent multimode model, we demonstrate the applicability of this approach to provide ~1-MW radiation in a 230-GHz SH gyrotron with the high-order TE<sub>34,14</sub> operating mode which is standardly unattainable for harmonic operation.