X波段高效率速调型相对论返波管研究  

Investigation of an X band high efficiency klystron-like relativistic backward wave oscillator

作　　者：杨德文 陈昌华 史彦超 肖仁珍 滕雁 范志强 刘文元 宋志敏 孙钧 Yang De-Wen;Chen Chang-Hua;Shi Yan-Chao;Xiao Ren-Zhen;Teng Yan;Fan Zhi-Qiang;Liu Wen-Yuan;Song Zhi-Min;Sun Jun(Science and Technology on High Power Microwave Laboratory,Northwest Institution of Nuclear Technology,Xi’an 710024,China;Tsinghua University,Beijing 100084,China)

机构地区：[1]西北核技术研究院高功率微波重点实验室,西安710024 [2]清华大学,北京100084

出　　处：《物理学报》2020年第16期66-76,共11页Acta Physica Sinica

摘　　要：本文对一种高效率速调型RBWO进行了理论分析和实验研究.通过理论分析,给出两个预调制腔间距的选择依据;提出一种高功率容量的椭圆形提取腔,可使得提取腔内表面场强降低约25%;分析了磁场分布对效率的影响,结果表明:使用特殊设计的引导磁场,可克服器件转换效率对收集位置的强烈依赖;分析了阴阳极间距对效率的影响,结果表明:随着阴阳极间距增大,器件的最优工作电压降低,并且效率有所提升.在实验中获得X波段微波功率为2.15 GW,脉宽达到25 ns,转换效率为50%(±5%).实验结果与理论和数值模拟结果吻合.This paper investigates an X band high efficiency klystron-like relativistic backward wave oscillator(RBWO) in detail. The klystron-like RBWO consists of a pre-modulation cavity, a resonant reflector with a ridge, a sectional slow wave structure, and an extraction cavity. First, this paper gives some theoretical studies about beam modulation and energy extraction. For beam modulation, the optimized distance between the premodulation cavity and the resonant reflector is studied theoretically, and theoretical results agree well with simulation results. For energy extraction, an ellipse extraction cavity with high power capacity is come up with,and the electric field on the inner surface of the ellipse extraction cavity decreases by 25% in PIC simulation.Also, the paper analyzes the effect of the position of dumped electron on conversion efficiency. Interestingly, it’s found that the efficiency dramatically decreases with the increase of the distance between the extraction cavity and the position of dumped electron, which is caused by the increase of potential energy of electron and the decrease of electric field. Fortunately, we find that the use of guiding magnet with special magnetic field distribution almost eliminate this unfavorable effect. Besides, effects of the distance between the cathode and anode Lak are investigated. It’ s shown that the optimized diode voltage decrease with the increase of the distance Lak, and the conversion efficiency is higher at larger Lak. The experimental studies are also given. The power capacity of ellipse extraction cavity is verified, also we find that the efficiency is enhanced by 10% and the width of microwave pulse increases by 7 ns when the roughness of RF structure surface is improved from Ra0.4 μm to Ra 0.05 μm. Typically, the klystron-like RBWO outputs X band high power microwave with power of 2.15 GW, with pulse duration of 25 ns, and with conversion efficiency of 50%(± 5%). Experimental results agree well with theoretical and PIC simulation results.

关 键 词：高效率 速调型 相对论返波管 高功率微波 

分 类 号：TN125[电子电信—物理电子学]