Ku波段相对论扩展互作用速调管振荡器粒子模拟研究  

Particle simulation study of Ku-band relativistic extended interaction klystron oscillator

作　　者：蒋俊杰 阳福香 党方超 葛行军 张鹏[1] 李家文[1] 邓如金 李志敏 Jiang Junjie;Yang Fuxiang;Dang Fangchao;Ge Xingjun;Zhang Peng;Li Jiawen;Deng Rujin;Li Zhimin(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学前沿交叉学科学院,长沙410073

出　　处：《强激光与粒子束》2024年第10期137-143,共7页High Power Laser and Particle Beams

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。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.

关 键 词：扩展互作用 功率容量 射频电场 模式竞争 

分 类 号：TN752.5[电子电信—电路与系统]