Abstract-Terahertz gyrotrons with quasi-regular cavities

 Ivan V. Osharin,  Ilya V. Bandurkin,  Yury K. Kalynov, Audrey V. Savilov

http://ieeexplore.ieee.org/document/8105117/

We describe two ways of the use in high-harmonic gyrotrons of quasi-regular cavities with short irregularities formed by the widening of cavity radius. The first one is a significant improvement of the selectivity of the second-harmonic gyrotrons due to the supression of parasitic near-cutoff fundamental-harmonic waves. The second approach is aimed to solve a typical problem of weakly-relativistic high-harmonics gyrotrons, namely, the use of long cavities ensuring extremely high diffraction Q-factors and a great share of Ohmic losses. We propose a quasi-regular cavity with periodic phase correctors, where a far-from-cutoff axial mode with a decreased diffraction Q-factor is excited in a gyrotron-like regime.

Abstract-Method of Providing the High Cyclotron Harmonic Operation Selectivity in a Gyrotron With a Spatially Developed Operating Mode

 Ilya V. Bandurkin,   Mikhail Yu Glyavin,   Sergey V. Kuzikov,  Petr B. Makhalov,   Ivan V. Osharin,  Andrey V. Savilov

http://ieeexplore.ieee.org/document/8002605/

An electrodynamic method for suppressing low-frequency oscillations at the fundamental cyclotron resonance in a gyrotron at a high cyclotron harmonic is proposed and theoretically investigated. According to simulations, the use of this method in the terahertz gyrotron at the second cyclotron harmonic operating at the spatially developed mode TE63,15 can provide a multiple excess of the starting currents of the parasitic modes over the starting current of the desired oscillations.