Recent progress of high‐power millimeter wavelength gyrodevices

This presentation reviews recent progress of Russian physicists in developing electronic devices of the gyroresonance type, which are so far the most advanced sources of millimeter microwaves. It deals with the concept of the gyrotron as a device operating at higher volume resonator modes with a built‐in quasioptical converter of the output radiation into a wave beam. That concept made it possible to create comparatively simple and reliable long‐pulse and quasicontinuous devices with a power level of 0.5 MW in the frequency band 30–160 GHz. Analysis of the principal problems of projects for continuous‐wave (CW) gyrotrons of near 1 MW output power (choice of an operating mode, requirements to an electron beam, peculiarities of built‐in converters) is included, as well as the results of model experiments. For amplifying millimeter wavelength gyroklystrons, a level of several hundreds of kW at the frequency 35 GHz, and up to 65 kW at frequency 94 GHz were also achieved. Some modifications of gyrotrons for material processing and special research are described.