Particle simulation study of Ku-band relativistic extended interaction klystron oscillator
-
摘要: 射频击穿、模式竞争是导致速调管振荡器（RKO）功率下降、脉冲缩短的主要原因。本文引入扩展互作用提取结构，可以有效降低提取腔射频电场，增大器件功率容量。传统的双间隙提取结构将电子能量在提取腔内转化为微波能量，共用一个通道输出。而扩展互作用提取结构采用了分布式提取腔而非集中式提取腔，增加了输出通道，可以有效提高束-波转换效率，降低提取腔的射频电场。粒子模拟结果显示：二极管电压561 kV，磁场强度0.5 T条件下，保持阴极结构、调制腔及反射器不变时，分别对传统双间隙提取腔、双间隙及三间隙扩展互作用提取腔进行仿真：输出功率分别为2.14、2.22、2.35 GW；分析其提取腔最大射频电场，分别为1.50、1.21、1.10 MV/cm；束波转换效率分别为35.7%、36.9%、39.1%；器件工作频率为12.52 GHz。在三维仿真中，通过改变阴极结构的S参数、设计新的反射器，有效抑制了调制腔TM113模带来的模式竞争，为开展后续实验奠定了基础。Abstract: RF breakdown and mode competition are the main causes of power reduction and pulse shortening of klystron oscillator (RKO). This paper introduces an extended interaction extraction structure, which can effectively reduce the RF electric field of the extraction cavity and increasing the power capacity. The traditional double-gap extraction structure converts electron energy into microwave energy in an extraction cavity and shares one channel for output. However, the extended interaction extraction structure adopts a distributed extraction cavity instead of a centralized extraction cavity, which increases the output channel, thus it can effectively improve the beam-wave conversion efficiency and reduce the RF electric field of the extraction cavity. The results of particle simulation show that the output power is 2.14 GW, 2.22 GW, 2.35 GW for the traditional two-gap extraction cavity, the two-gap extraction cavity and the three-gap extended-interaction extraction cavity, respectively, when the diode voltage is 561 kV and the magnetic field strength is 0.5 T. The maximum RF electric field of the extraction cavity is 1.50 MV/cm, 1.21 MV/cm and 1.10 MV/cm, respectively. The beam-wave conversion efficiency was 35.7%, 36.9% and 39.1%, respectively. The operating frequency of the device is 12.52 GHz. In the 3D simulation, by changing the S parameter of the cathode structure and designing a new reflector, the mode competition caused by TM113 mode of the modulation cavity is effectively suppressed, which laid the foundation for subsequent experiments.
-
Key words:
- extended interaction /
- power capacity /
- RF electric field /
- mode competition
-
图 1 相对论扩展互作用速调管振荡器示意图
Figure 1. Schematic diagram of a relativistic extended interaction klystron oscillator
1-dual annular cathode, 2-reflective cavity, 3-modulation cavity, 4-extended interaction extraction, 5-collector
图 2 归一化电场分布示意图和其对应的电子束负载电导
Figure 2. Normalized electric field distribution and electron conductivity
图 4 射频电场及输出功率对比示意图
Figure 4. Schematic diagram of RF electric field and output power comparison
图 5 提取腔电子束功率下降对比示意图
Figure 5. Comparison of power drop of the electron beam in the extraction cavity
图 10 新反射器TEM模与TE11模的S参数
Figure 10. S-parameters of the new reflector TEM mode and TE11 mode
-
[1] 王文祥. 微波工程技术[M]. 北京: 国防工业出版社, 2009Wang Wenxiang. Microwave engineering technology[M]. Beijing: National Defense Industry Press, 2009 [2] 令钧溥. Ku波段低磁场同轴渡越时间振荡器的研究[D]. 长沙: 国防科学技术大学, 2014Ling Junpu. Investigation of a Ku-band coaxial transit-time oscillator with low guiding magnetic field[D]. Changsha: National University of Defense Technology, 2014 [3] 宋莉莉. Ka波段高功率同轴渡越时间振荡器的研究[D]. 长沙: 国防科学技术大学, 2018Song Lili. A Ka-band high power coaxial transit-time oscillator[D]. Changsha: National University of Defense Technology, 2018 [4] Dang Fangchao, Yang Fuxiang, Ge Xingjun, et al. A Ku-band compact disk-beam relativistic klystron oscillator operating at low guiding magnetic field[J]. IEEE Access, 2021, 9: 84170-84177. doi: 10.1109/ACCESS.2021.3079517 [5] Ling Junpu, Xu Weili, He Juntao, et al. Experimental research on a gigawatt-class Ku-band coaxial transit-time oscillator with low guiding magnetic field[J]. Physics of Plasmas, 2022, 29: 073105. doi: 10.1063/5.0092985 [6] 陈代兵, 刘庆想, 何琥, 等. X波段五腔渡越管振荡器的理论与实验研究[J]. 强激光与粒子束, 2005, 17(1):93-98Chen Daibing, Liu Qingxiang, He Hu, et al. Theoretical and experimental researches on the X-band five-unit transit-time tube oscillator[J]. High Power Laser and Particle Beams, 2005, 17(1): 93-98 [7] Gao Xingfu, Song Lili, Zhang Haoran, et al. A novel Ka-band coaxial transit time oscillator with internal extraction[J]. Review of Scientific Instruments, 2021, 92: 094704. doi: 10.1063/5.0062144 [8] Gao Xingfu, Song Lili, Wang Lei, et al. A high-power relativistic Ka-band millimeter-wave coaxial transit time oscillator with stable repetitive operation at low guiding magnetic field[J]. IEEE Transactions on Microwave Theory and Techniques, 2024, 72(3): 1529-1535. doi: 10.1109/TMTT.2023.3307762 [9] Ling Junpu, He Juntao, Zhang Jiande, et al. A novel Ku-band relativistic transit-time oscillator with three-cavity extractor and distance-tunable reflector[J]. Physics of Plasmas, 2017, 24: 013103. doi: 10.1063/1.4973329 [10] Ju Jinchuan, Chen Yinghao, Zhou Yunxiao, et al. A coaxial high power output cavity operating in hybrid TM01-TM02 modes for repetitive operation[J]. IEEE Electron Device Letters, 2021, 42(10): 1551-1554. doi: 10.1109/LED.2021.3108536 [11] 邓秉方. 低磁场V波段相对论渡越时间振荡器研究[D]. 长沙: 国防科学技术大学, 2021Deng Bingfang. Investigation of a V-band relativistic transit-time oscillator with low guiding magnetic field[D]. Changsha: National University of Defense Technology, 2021 [12] Pasour J, Smithe D, Friedman M. The triaxial klystron[J]. AIP Conference Proceedings, 1999, 474(1): 373-385. [13] Pasour J, Smithe D, Ludeking L. X-band triaxial klystron[J]. AIP Conference Proceedings, 2003, 691(1): 141-150. [14] Xiao Renzhen, Song Zhimin, Yang Dewen, et al. Efficiency enhancement of a klystron-like relativistic backward wave oscillator with local decompression magnetic field[J]. Physics of Plasmas, 2019, 26: 013104. doi: 10.1063/1.5055582 [15] 令钧溥, 贺军涛, 张建德, 等. 行波提取型同轴渡越时间振荡器模拟[J]. 国防科技大学学报, 2013, 35(6):120-125 doi: 10.3969/j.issn.1001-2486.2013.06.021Ling Junpu, He Juntao, Zhang Jiande, et al. Numerical study of a coaxial transit-time oscillator with travelling-wave output structure[J]. Journal of National University of Defense Technology, 2013, 35(6): 120-125 doi: 10.3969/j.issn.1001-2486.2013.06.021 [16] Ling Junpu, He Juntao, Zhang Jiande, et al. Suppression of the asymmetric competition mode in the relativistic Ku-band coaxial transit-time oscillator[J]. Physics of Plasmas, 2014, 21: 103108. doi: 10.1063/1.4900408 [17] Song Lili, He Juntao, Ling Junpu, et al. Experimental research on Ka-band coaxial transit-time oscillator[J]. Physics of Plasmas, 2018, 25: 063107. doi: 10.1063/1.5025908 -
下载:
点击查看大图
图(11)
计量
- 文章访问数: 57
- HTML全文浏览量: 24
- PDF下载量: 7
- 被引次数: 0
