C波段50 MW行波输出速调管设计

设计了导流系数1.53 P的电子枪，枪内场强低于22.1 kV/mm，阴极平均负载小于6.3 A/cm2；采用部分屏蔽流均匀场电磁聚焦系统，实现了对电子注的良好聚焦；设计了C波段/2模盘荷波导行波输出结构，采用CST软件对其色散特性、耦合阻抗进行了计算分析。首先以单间隙输出腔代替行波输出结构对5腔注-波互作用系统进行计算，确定了前4腔的设计参数，然后采用PIC模拟软件对具有盘荷波导结构的输出系统进行了三维模拟，获得了大于50 MW的输出功率，效率大于45%，饱和增益大于50 dB，盘荷波导结构间隙电压比单间隙输出腔下降30%，效率提高4%。

Design of C-band 50 MW klystron with traveling wave output structure

This paper presents the simulation study of a C-band 50 MW klystron with disc-loaded waveguide traveling wave output structure. The electron gun with a perveance of 1.53 μP is designed. The gun has a voltage gradient lower than 22.1 kV/mm and a cathode load current lower than 6.3 A/cm2. The beam focusing system is a space-charge balanced flow type with solenoid magnet structure and the focusing beam trajectories have a good laminar condition. A single gap cavity is adopted instead of the traveling wave output structure in the initial beam-wave interaction simulation to decide the parameters of the cavities except the output structure. A C-band disc-loaded waveguide output structure working at π/2 mode is designed and the dispersion and interaction impedance of the structure are determined by the CST code. The beam-wave interaction system with disc-loaded waveguide output structure is simulated by a three-dimensional PIC code. More than 50 MW output power is obtained. The efficiency is more than 45% and the saturate gain is more than 50 dB. The voltage gradient of the disc-loaded waveguide output structure is 30 percent less than that of the single gap cavity and there is an increase of 4% in efficiency above that of the single gap cavity.