Sub-GW Power Spatially-Extended Surface-Wave Oscillators of Cylindrical Geometry with Two-Dimensional Distributed Feedback Operating at Ka and W Bands

Original conception of spatially-extended high-power Cherenkov masers is under development in IAP RAS (N.Novgorod). 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. The paper describes recent results of theoretical and experimental studies of the Surface-Wave Oscillators (SWO) of cylindrical geometry with 2D distributed feedback driven by high-current accelerator “Sinus-6” 500 keV / 5 kA / 25 ns. In the proof-of-principal experiment carried out at the Ka-band, a narrow-band generation with output power of about 200 - 250 MW was obtained at the oversize factorØ/λ ~ 5. In accordance with the simulations efficient operation of the SWO at the W-band was demonstrated in a narrow-band oscillation regime with an output power of about 150 - 200 MW at the oversize factor Ø/λ ~ 10.