Development of a magnetic cusp gun for a 1-THz harmonic gyrotron

Li, Fan-Hong and Du, Chao-Hai and Zhang, Zi-Wen and Li, Si-Qi and Gao, Zi-Chao and Zhu, Juan-Feng and Ma, Guo-Wu and Huang, Qi-Li and Ma, Hong-Ge and Zhang, Liang and Cross, Adrian W. and Liu, Pu-Kun (2021) Development of a magnetic cusp gun for a 1-THz harmonic gyrotron. IEEE Transactions on Electron Devices. pp. 1-6. ISSN 0018-9383 (In Press)

[thumbnail of Li-etal-IEEE-TED-2021-Development-of-a-magnetic-cusp-gun]
Text. Filename: Li_etal_IEEE_TED_2021_Development_of_a_magnetic_cusp_gun.pdf
Accepted Author Manuscript

Download (1MB)| Preview


High-quality axis-encircling electron beam is essential to drive a high-harmonic gyrotron. A magnetic cusp gun that can generate a low-spread axis-encircling electron beam at an extremely high magnetic-compression ratio was developed for a 1-THz 4th-harmonic gyrotron toward continuous-wave operation. The optimized gun could generate an axis-encircling electron beam with 80-kV voltage, 1-A current, and a nearly constant pitch factor of about 1.5 in a wide range of magnetic field strength. The transverse velocity spread was less than 2.1% and the guiding center radius was 26.6 µm. The design was verified by using MAGIC, EGUN, and CST simulations and good agreements were achieved.