Powerful Cherenkov Masers With 2d Slow-Wave Structures Intended For Powering Systems Of Compton-Type Fels

Spatially-extended high-power Cherenkov masers operating in millimeter wavelength band intended for using in powering systems of Compton-type FELs are under development in collaboration of IAP RAS (Nizhny Novgorod) and BINP RAS (Novosibirsk). Electrodynamic systems of such oscillators are based on 2D periodical slow-wave structures realizing 2D distributed feedback mechanism, allowing for provision of stable narrow-band oscillation regime under conditions of substantial oversize. This novel feedback mechanism is examined for the oscillators of different geometry. Project of cylindrical slow-wave oscillator of such type operating at Ka-band with sub-GW power level was elaborated based on the tubular electron beam at the "Sinus-6" accelerator 0.5 MeV / 5 kA / 20 ns (IAP RAS). Prospect for further increase of the radiation power is studied in W-band planar Cherenkov maser driven by large-size sheet electron beam forming by the "ELMI" accelerator 1 MeV / 7 kA / 3 mu s (BINP RAS). Design parameters, key components and results of simulations of these oscillators are presented, status and results of their experimental studies are discussed.