Tunable Multi-Frequency Radiation Source Based on Gyrotron With Pre-Modulated Beam

• Published in: IEEE electron device letters Vol. 43; no. 5; pp. 809 - 812
• Main Authors: Guznov, Yu. M., Leontyev, A. N., Rozental, R. M., Sergeev, A. S., Zotova, I. V., Ginzburg, N. S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-05-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Cathodes; Cyclotron frequency; Cyclotron resonance devices; Cyclotrons; Electron beams; Extremely high frequencies; Frequency modulation; Frequency ranges; gyroklystron; gyrotron; Gyrotrons; Klystrons; Locking; Mathematical models; Modulation; Multi-frequency radiation; Plasma waves; Radiation; Radiation sources; Self excitation
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2022.3163153

We propose a multi-frequency radiation source based on a gyrotron which is driven by a pre-modulated electron beam. Modulation occurs in an additional cavity powered by an external weak monochromatic signal with a frequency outside the gyrotron locking band. Using parameters of a 170 GHz MW-level gyrotron as an example, we demonstrate in simulations that an external power of only 0.05-0.2% of the power of free-running generation is sufficient to provide beats regimes with controllable 15-25 MHz interval between main practically equal spectral components. The proposed radiation source is suitable for excitation of plasma waves in the ion-cyclotron frequency range. Theoretical considerations are confirmed in proof-of-principle experiments based on a Ka-band relativistic gyroklystron operating in the self-excitation mode and controlled by the input wave.