CC BY
3LS-O-10
ALT'23
The 30th International Conference on Advanced Laser Technologies
Gyrotrons: impossible is nothing
G.Denisov, A.Litvak, E.Tai, M. Glyavin and IAP RAS/GYCOM team
Institute of Applied Physics RAS (IAP RAS), 46 Ul 'yanov str., Nizhny Novgorod, Russia GYCOMLtd., 46 Ul'yanov str., Nizhny Novgorod, Russia
There are a number of topical scientific problems that require the creation of powerful sources of microwave electromagnetic radiation in the frequency range 0.1-1 THz. Gyrotrons are the most powerful radiation sources in the sub-THz and THz wavelength ranges. Despite the difficulties with the generation of high-intensity magnetic fields required for resonant conditions of electron-wave interaction in volumes sufficient to accommodate electron-optical and electrodynamics systems of gyro devices, the problem of shaping highpower electron fluxes with a high fraction of rotational energy and low velocity spread, and the problem of selective excitation of high-order operating modes, harmonic excitation, etc., the gyrotrons continue to be the object of intense research and show a significant potential for improving the characteristics of the generated radiation [1,2].
Gyrotrons are in demand for the ECR of plasmas in controlled-fusion installations, the creation of systems for high-gradient acceleration of electrons by terahertz waves, energy transfer using narrow beams of microwave radiation, spectroscopy, and diagnostics of various media.
The years 2021-2022 were marked by an increase in the number of requests for megawatt (MW) gyrotrons both from representatives of large thermonuclear facilities well known to the gyrotron community (ITER, KSTAR, EAST) and from a number of new projects (F4E, MAST-U). An explosive growth in the number of commercial companies that focus on obtaining thermonuclear energy by 2025-2030 should be mentioned [3].
The purpose of this paper is to present a number of the most striking achievements of the IAP RAS and GYCOM in the development of gyro devices, which include: i) testing a prototype MW level gyrotrons with a frequency of 230-250 GHz in a pulsed generation mode, ii) development and experimental tests of frequency locked operation regime with narrow spectrum line at different tubes, including 1MW/170GHz gyrotron; iii) development of a pulse compressor circuit for a high-power gyrotron and preliminary analysis of its key elements for provision of microwave radiation with a power level of about 100 MW and a pulse duration of about 10 ns; v) development and experimental investigation of high power and efficiency gyrotron based technological systems with magnetically shield solenoid and vi) analysis of new schemes for broadband frequency tuning and excitation of higher harmonics.
The gyrotron development is supported by the IAP RAS projects FFUF-2021-0001, FFUF-2022-0007. Development, manufacturing and experimental test of ITER gyrotrons are supported by project 17706413348230000070/45-393 in the frame of the work "Development, pilot production and supply of 8 sets of gyrotrons with magnets and auxiliary equipment for the ITER plasma heating and current drive ECR system".
[1] A. G. Litvak, G. G. Denisov and M. Y. Glyavin, "Russian Gyrotrons: Achievements and Trends", IEEE Journal of Microwaves, 1, 1, 260 (2021) DOI: 10.1109/JMW.2020.3030917
[2] Sabchevski, S., Glyavin, M., Mitsudo, S. etal. Novel and Emerging Applications of the Gyrotrons Worldwide: Current Status and Prospects. J InfraredMilli Terahz Waves 42, 715-741 (2021) DOI: 10.1007/s10762-021-00804-8
[3] "The global fusion industry in 2022" Fusion Industry Association https://www.fusionindustryassociation.org/about-fusion-industry (available online 10.12.2022
