New-type periodical permanent magnet focus system for G band extended interaction klystron
-
摘要: 提出了一种新型周期永磁（PPM）聚焦系统，其中，每半个周期的这种PPM聚焦系统由1件极靴和5块永磁体共同组成，第1、第3、第5块永磁体与第2、第4块永磁体的极化方向相反，且任何相距半个周期的2块永磁体均具有相反的极化方向。采用MTSS2018对这种新型PPM聚焦系统的磁场进行了计算，结果表明新型PPM聚焦系统的轴线上磁感应强度Bz具有显著的第3次和第5次空间谐波，在过0点后能够更快上升到峰值，整体构型十分接近具有理想矩形分布的PPM系统。采用MTSS2018对G波段分布作用速调管（EIK）所需的电子枪进行了模拟计算，并采用上面计算的Bz对该电子注进行聚焦，获得了电子注电压为22 kV，电子注电流为215 mA的电子注，电子注最大半径为0.08 mm，满足G波段EIK的应用要求。计算中的峰值磁感应强度仅为1.2
$ \sqrt 2 $ BB，说明新型PPM聚焦系统与传统PPM聚焦系统相比，可以在较低的峰值磁感应强度的条件下实现电子注的有效聚焦。Abstract: This paper proposes a new-type periodical permanent magnet (PPM) focus system, each half period of which is composed of 1 magnetic pole and 5 permanent magnets, and the first, the third and the fifth magnets have reverse magnetization with the second and the fourth magnets. Besides, any two magnets spaced half period have inverse magnetization with each other. The new-type PPM focus system is modeled and calculated by MTSS2018, the results show that the axial component Bz of the magnetic induction intensity on the axis has conspicuous amplitude of the third and the fifth space harmonics, and Bz rises steeply after it reaches zero, so Bz has a profile very approximate to the periodical rectangular shape. An electron gun under the condition of the above calculated Bz is calculated by MTSS2018 too, a beam with 22 kV of voltage, 215 mA current and 0.08 mm of maximum beam radius is obtained, which meets the demand of G band extended interaction klystron (EIK). In the calculations the peak value of Bz is only 1.2$ \sqrt 2 $ BB (subscript B is Brillouin magnetic field), it suggests that the new-type PPM focus system focuses the beam effectively even if it has a relatively lower peak value of Bz than the conventional PPM focus system does. -
图 1 电子枪的MTSS2018模型及计算结果
Figure 1. MTSS2018 model for calculating the electron gun and the calculated results
图 2 新型PPM聚焦系统及其MTSS2018计算模型和计算结果
Figure 2. MTSS2018 model for calculating the magnetic fields of the new-type PPM focus system and the calculated results
图 3 在两种不同Bz构型的磁场的电子注电子轨迹的计算结果
Figure 3. Projective view of electron tracks in the beam when two kinds of PPM focus systems with different Bz profile are added
图 4 传统PPM聚焦系统的MTSS2018计算模型及其计算结果
Figure 4. MTSS2018 model for calculating the conventional PPM focus system and the calculated results
图 5 采用传统PPM聚焦系统时的电子注轨迹
Figure 5. Projective view of electron tracks in the beam when the conventional PPM focus system focus system is added
-
[1] John H B, Richard J D, Colin D J, et al. Vacuum electronic high power terahertz sources[J]. IEEE Trans Terahertz Science and Technology, 2011, 1(1): 54-75. doi: 10.1109/TTHZ.2011.2151610 [2] Albert R, Dave B, Mark H, et al. Sub-millimeter waves from a compact, low voltage extended interaction klystron[C]//Proc of IRMMW-THz. 2007: 1-3. [3] Mark H, Albert R, Peter H, et al. A compact, high power, sub-millimeter-wave extended interaction klystron[C]//Proc of IVEC. 2008: 297. [4] Peter H, Albert R, Richard D, et al. Compact sources of high RF power for DNP applications[C]. Proc of IVEC 2014: 221-222. [5] Albert R, Mark H, Peter H, et al. Development of sub-millimeter high power compact EIKs for DNP and radar applications[C]//Proc of IVEC. 2017: ID62 [6] Richard D, Albert R, Peter H, et al. Design and fabrication of terahertz extended interaction klystrons[C]//Proc of IRMMW-THz. 2010: 1-3. [7] Richard D, Albert R, Peter H, et al. Fabrication techniques for a THz EIK[C]//Proc of IVEC. 2010: 181-182. [8] Zhang Kaichun, Wu Zhenhua, Liu Shenggang. Study of an extended interaction oscillator with a rectangular reentrance coupled-cavity in terahertz region[J]. J Infrared Milli Terahz Waves, 2009, 30: 308-318. [9] Qu Zhaowei, Zhang Zhiqiang, Ding Yaogen, et al. Research progress of a W-band 100-Watts extended interaction oscillator[C]// Proc of IVEC. 2017: ID94. [10] 王自成, 唐伯俊, 谢文球, 等. 0.22 THz高效率行波管的互作用计算[J]. 强激光与粒子束, 2016, 28:023101. (Wang Zicheng, Tang Bojun, Xie Wenqiu, et al. RF system of a 220 GHz extended interaction klystron[J]. High Power Laser and Particle Beams, 2016, 28: 023101 doi: 10.11884/HPLPB201628.023101 [11] 电子管设计手册编辑委员会. 微波管电子光学系统设计手册[M]. 北京: 国防工业出版社, 1981.Editorial Board of Designers’ Handbook on Electron Tubes. Designers’ handbook on electron optics system in microwave tubes[M]. Beijing: National Defense Industry Press, 1981 -
下载:
点击查看大图
计量
- 文章访问数: 1688
- HTML全文浏览量: 339
- PDF下载量: 58
- 被引次数: 0
