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6Gyrotrons: towards to the design of powerful THz radiation source
G.G. Denisov1, E.M. Tai12, A.N. Kuftin1, Y.K. Kalynov1, S.V. Samsonov1, A.V. Savilov1, E.A. Soluyanova12, A.P. Fokin12, M.Yu. Givavin1'
1-Institute of Applied Physics RAS,46 Ul'yanov str., Nizhny Novgorod, Russia 2- GYCOMLtd., 46 Ul'yanov str., Nizhny Novgorod, Russia
Gyrodevices, in particular gyrotrons, currently are the most popular sources of powerful radiation in the sub-THz and THz frequency band [1,2]. The main area of gyrotron applicating associated with electron cyclotron resonance heating (ECH) and current drive in controlled thermonuclear fusion (NF) facilities. For the ITER project, GYCOM/IAP RAS implemented a CW (pulse duration of about 1000 sec) gyrotron with a MW power level at a frequency of 170 GHz [2,3]. Currently, in connection with an increase of ECH power from 24 MW (24 tubes) to 48 MW and, in the future, up to 80 MW, the possibility of 1.2 - 1.5 MW gyrotrons is being discussed. The solution connected to utilization of higher operating modes and using an external signal for frequency locking and suppression of parasitic oscillations [4]. For the next generation of NF installations this purpose, a powerful gyrotron with an operating frequency of 230 GHz has been developed [5]. The mastering of the terahertz frequency range by gyro-devices continues, and the main attention is paid not even to achieving record values of power and efficiency, but to controlling of the spectral characteristics [6] and searching for possibilities for smooth frequency tuning, which is due to the prospects of spectroscopy applications. Through the use of original methods of electronic and electrodynamic selection, stable single-mode generation at cyclotron harmonics was achieved at frequencies up to 1.2 THz [7-9]. Work is underway to create HTSC magnetic systems, which makes it possible to expect operating frequencies of gyrodevices up to 2 THz. The possibility of frequency multiplication has been demonstrated [10], which makes it possible to obtain tens of Watts in continuous mode at frequencies up to 1.5 THz. Using an original electrodynamic system based on quasi-optical elements, tuning of the generation frequency in a band of about one octave was demonstrated [11].
Development of gyro devices was supported, in particular, by the IAP RAS projects FFUF-2022-0007 and FFUF-2024-0027.
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