一种X波段过模高效率相对论返波管  

A high efficiency X-band over-mode relativistic backward wave oscillator

作　　者：史彦超[1] 滕雁[1] 陈昌华[1] 肖仁珍[1] 邓昱群 杨德文 王东阳[1] 孙钧[1] Shi Yanchao;Tong Yan;Chen Changhua;Xiao Renzhen;Dcng Yuqun;Yang Dewen;Wang Dongyang;Sun Jun(Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi＇an 710024, China)

机构地区：[1]西北核技术研究所高功率微波技术重点实验室,西安710024

出　　处：《强激光与粒子束》2018年第7期33-37,共5页High Power Laser and Particle Beams

摘　　要：设计了一种X波段过模高效率相对论返波管(RBWO),主要结构包括双谐振腔反射器、7周期梯形慢波结构与提取腔。该器件慢波结构的过模比为2.6,电子束与结构波TM_(01)模的近π模相互作用,在慢波结构区域束波作用产生的TM_(01)模表面波主要转化为TM_(02)模的体波,其输出微波的模式主要为TM_(02)模,占比为81%,其余为TM_(01)模。提出一种过模条件下谐振腔反射器的设计思路,结合模式匹配法,优化得到了一种双谐振腔反射器结构,其对TM_(01)模与TM_(02)模的反射系数均大于0.99,可实现过模条件下RBWO慢波结构与二极管区的良好隔离;同时双谐振腔反射器两个谐振腔中的纵向电场可以对电子束进行充分的预调制,将促进慢波结构区域的束波作用,有利于提升效率。通过在慢波结构后端加入提取腔,进一步提升了转换效率。PIC仿真中,在二极管电压900kV,电流14.3kA,得到了6.6GW的输出功率,转换效率约51%。This paper studies a high efficiency X-band over-mode relativistic backward wave oscillator（RBWO）,which is composed of a dual-cavity reflector,a 7-periods trapezoid SWS and extraction cavity.The ratio of Dtoλof the generator is 2.6,and the electron beam interacts with the TM01 nearπmode of the structure wave.In the SWS region the TM01 mode surface wave mainly transfers to the TM02 mode body wave,the primary mode of the output microwave is TM02 mode with the proportion 81%,and the remainder is TM01 mode.A method to design the resonant reflector under over-mode condition is proposed,a dualcylindrical cavity reflector is optimized by using the mode-matching method,and the reflection coefficients for the TM01 and TM02 modes are larger than 0.99,hence good insulation between the SWS and the diode is achieved.Simultaneously,the longitudinal electric field of the resonant reflector could pre-modulate the electron beam sufficiently,which would promote the beam-wave interaction in the SWS.Furthermore,the transfer coefficient is increased by loading the extraction cavity after the SWS.Simulation results indicate that microwave output power of 6.6 GW is achieved,the diode voltage is 900 kV and beam current is 14.3 kA,and the transfer efficiency is 51%.

关 键 词：高功率微波 相对论返波管 过模 谐振反射器 

分 类 号：TN125[电子电信—物理电子学] TN122