Powerful Cherenkov Masers with 2D Slow-wave Structures of Planar and Cylindrical Geometry

• Published in: 2021 Photonics & Electromagnetics Research Symposium (PIERS) pp. 1078 - 1085
• Main Authors: Peskov, N. Yu, Abubakirov, E. B., Arzhannikov, A. V., Denisenko, A. N., Ginzburg, N. S., Kalinin, P. V., Sandalov, E. S., Sinitsky, S. L., Stepanov, V. D., Vikharev, A. A., Zaslavsky, V. Yu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 21.11.2021
• Subjects: Collaboration; Electrodynamics; Electromagnetics; Electron beams; Geometry; Masers; Oscillators
• ISSN: 2694-5053
• DOI: 10.1109/PIERS53385.2021.9695065

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 Ka-band Cherenkov Surface-Wave Oscillator of sub-GW power level is elaborated based on high-current explosive-emission accelerator "Sinus-6" 0.5MeV/5kA/20ns (IAP RAS) forming relativistic electron beam of a tubular geometry with diameter of about 40mm. To ensure high-coherence of the radiation from the large-size beam, we exploit cylindrical slow-wave structure with 2D doubly-periodical corrugation. In the proof-of-principal experiments under the transverse oversize parameter of the system (perimeter to the wavelength) of about 16, the narrow-band oscillations was obtained with the power level of \sim 0.25-0.3 \mathrm{GW}. Optimization of parameters aimed at further power enhancement is in progress currently.Project of powerful W-band Cherenkov maser of planar geometry is under development in collaboration between IAP RAS and BINP RAS at the "ELMI" accelerator. This accelerator forms electron beam 1MeV/5-7kA/ 3 \mu \mathrm{s} of sheet geometry with the transverse cross-section of 0.3cm \times18 cm. In present paper, design parameters of this project are discussed and results of the simulations are presented, which demonstrate possibility to achieve in the considered scheme a stable narrow-band oscillation regime with output power of the GW-level under the transverse oversize parameter (width to the wavelength) of up to 50. Experiments on realization of this super-power Cerenkov maser are started.