Development of a 1-THz 4th-harmonic gyrotron

Li, Fan-Hong and Du, Chao-Hai and Gao, Zi-Chao and Pan, Shi and Zhu, Juan-Feng and Zhang, Zi-Wen and Li, Si-Qi and Zhang, Liang and Cross, Adrian W.; (2020) Development of a 1-THz 4th-harmonic gyrotron. In: 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020. 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020 . Institute of Electrical and Electronics Engineers Inc., CHN. ISBN 9781728190648 (https://doi.org/10.1109/UCMMT49983.2020.9296084)

[thumbnail of Li-etal-UCMMT-2020-Development-of-a-1-THz-4th-harmonic-gyrotron]
Preview
Text. Filename: Li_etal_UCMMT_2020_Development_of_a_1_THz_4th_harmonic_gyrotron.pdf
Accepted Author Manuscript

Download (171kB)| Preview

Abstract

A design of a 1-THz 4th Harmonic Gyrotron is proposed in this paper. Fourth harmonic interaction is adopted to lower the strength of the external magnet. The magnet can be as low as 10T. Such a low-intensity magnetic field can be easily proposed by a superconduct magnet, which make the generation of continuous waves at 1 THz possible. Seeing that the mode competition is extremely fierce, a large orbit gun is employed as the driven source. An 80-kV, 0.7-A electron beam is injected into the interaction circuit to excite the fourth-harmonic electromagnetic waves. According to the cold dispersive diagram, the TE4, 8 mode of the cylindrical waveguide is selected as the operating mode to further suppress the mode competition induced by the fundamental modes, the 2nd harmonic modes and the 3rd harmonic modes. It could be inferred based on the multi-mode time-domain theory that an output power of 1.15 kW can be achieved. The scheme diagram for the hot test is proposed. The LOG is chosen as the electron gun. Particular structure is employed for improving the output efficiency in the interaction circuit.