Abstract-An Experimental Investigation of a 0.8 THz Double-Beam Gyrotron

Seitaro Mitsudo, Mikhail Glyavin, Eduard Khutoryan, Ilya Bandurkin, Teruo Saito. Yuya Ishikawa, Vladimir ManuilovIrina,  Zotova Alexey Fedotov.  Alexei  Kuleshov.  Svilen Sabchevski, Yoshinori Tatematsu, Vladislav Zaslavsky, Toshitaka Idehara,

https://link.springer.com/article/10.1007%2Fs10762-019-00629-6

In this paper, we present and discuss the new experimental results that characterize the output parameters, and the overall performance of the recently developed 0.8 THz double-beam gyrotron operating at the second harmonic of the cyclotron frequency on the TE8,5 mode. Alongside with this design mode, several other resonances excited at both the fundamental and second harmonic operations in a wide frequency range have been studied. These experiments demonstrate that the usage of a double-beam electron-optical system opens more possibilities for realization of such regimes of operation that otherwise are not accessible in a conventional (single-beam) gyrotron due to a severe competition between the neighboring modes and the narrowness of the zones of a stable single mode operation. Most notably, the results prove that second harmonic operation at higher beam currents and respectively at higher levels of the output power are possible as expected from the preceding theoretical considerations and numerical studies. The results of this study are helpful for getting a better insight in the physics of the operation of the double-beam gyrotrons and suggest some possibilities for further optimization of both the design of the tube and the experimental setup.

Abstract-High-power sub-terahertz source with a record frequency stability at up to 1 Hz

Alexander Tsvetkov  Gregory Denisov, Andrey Fokin, Boris Movschevich, German Golubiatnikov, Lev Lubyako, Mikhail Glyavin, Mikhail Morozkin, 

https://www.nature.com/articles/s41598-018-22772-1

Many state-of-the-art fundamental and industrial projects need the use of terahertz radiation with high power and small linewidth. Gyrotrons as radiation sources provide the desired level of power in the sub-THz and THz frequency range, but have substantial free-running frequency fluctuations of the order of 10−4. Here, we demonstrate that the precise frequency stability of a high-power sub-THz gyrotron can be achieved by a phase-lock loop in the anode voltage control. The relative width of the frequency spectrum and the frequency stability obtained for a 0.263 THz/100 W gyrotron are 4 × 10−12 and 10−10, respectively, and these parameters are better than those demonstrated so far with high-power sources by almost three orders of magnitude. This approach confirms its potential for ultra-high precision spectroscopy, the development of sources with large-scale radiating apertures, and other new projects.