The magnetic ring at the wave port position of the TWT periodic permanent magnet focusing system usually adopts single open magnetic ring. Two different double-open magnetic rings were proposed because of adding waveguide impedance tuning branch at the wave port position. The magnetic field near the central axis of the double-open magnetic ring was analyzed by using the 3D electromagnetic simulation software Opera-3D, and the design method of the periodic magnetic focusing system of double-open magnetic ring was put forward. In order to verify the feasibility of periodic permanent magnet focusing system with double-open magnetic rings, an electronic optical system of E-band folded waveguide TWT was designed and tested. In the traveling wave tube test, the emission current of the electron gun was 83 mA, and the electron beam flow rate of the periodic magnetic focusing system with double-open magnetic rings was 99%.
[3] 彭龙, 李元勋. 带开口磁环的周期永磁聚焦系统的轴向磁场[J]. 强激光与粒子束, 2011, 23(9):3552-3555. (Peng Long, Li Yuanxun. Magnetic field along central axis for periodic permanent magnetic focusing system with open magnetic rings. High Power Laser and Particle Beams, 2011, 23(9): 3552-3555
[4] 彭龙, 李元勋. 轴向磁化开口磁环在周期永磁聚焦系统中的应用[J]. 稀有金属材料与工程, 2011, 40(s2):476-479. (Peng Long, Li Yuanxun. Application of axially magnetized open magnetic ring in periodic permanent magnetic focusing system. Rare Metal Materials and Engineering, 2011, 40(s2): 476-479
[5] Zhang Qiang, Hu Yinfu, Pan Pan, et al. Electron optics design experiment of Gb TWT[C]IEEE 9th UKEuropeChina Wkshop on Millimeter Waves Terahertz Technologies. 2016: 147148.
[7] 宋睿, 周泉丰, 雷文强, 等. 0.22 THz折叠波导行波管电子光学系统设计与实验研究[J]. 强激光与粒子束, 2015, 27:093101. (Song Rui, Zhou Quanfeng, Lei Wenqiang, et al. Design and experiment of electron optical system for 0.22 THz folded waveguide traveling wave tube. High Power Laser and Particle Beams, 2015, 27: 093101
[8] 蔡竺吟, 吕国强, 杨蕾, 等. 行波管周期永磁聚焦系统的设计[J]. 真空电子技术, 2006(2):20-21. (Cai Zhuyin, Lv Guoqiang, Yang Lei, et al. Design of periodic permanent magnetic for traveling-wave tubes. Vacuum Electronics, 2006(2): 20-21
[9] 吉尔摩著. 速调管、行波管、磁控管、正交场放大器和回旋管[M]. 北京: 国防工业出版社, 2012.Gilmour A S. Klystrons, traveling wave tubes, magrons, crossedfield amplifiers, gyrotrons. Beijing: National Defense Industry Press, 2012
[10] 肖刘, 万晓声, 刘濮鲲, 等. 行波管过渡区磁场的研究与设计[J]. 微波学报, 2012(s2):392-395. (Xiao Liu, Wan Xiaosheng, Liu Pukun, et al. Research and design of magnetic field in transition area for traveling-wave tubes. Journal of Microwaves, 2012(s2): 392-395