四腔强流相对论速调管中高次模振荡的抑制

High-Order Mode Oscillation Suppression in Four-Cavity Intense Relativistic Klystron Amplifier

描述了在四腔强流相对论速调管模拟设计过程中出现的由于腔间耦合产生的高次模振荡现象,分析了这种振荡产生的原因,并从整管结果上探索了抑制这种高次模振荡的方法。利用MAGIC模拟软件,通过研究谐振腔Q值、漂移管长度、以及束波互作用程度等参数的变化对腔间耦合的影响,在极小程度降低输出微波功率的情况,有效抑制了腔间耦合。最终在功率10kW、频率2.88GHz的注入微波激励下,获得了功率3.7GW、效率22%、增益56dB且频谱纯的输出微波,有效抑制了高次模振荡。

This paper described a high-order mode oscillation phenomenon due to couplings between cavities, in the simulation of four cavity intense relativistic klystron （IRK）. The cause of this oscillation was analyzed and the suppression methods is explored from the whole tube. PIC particle simulation soft-ware is used to study the changes of parameters＇ （such as the cavity Q value, the drift tube length and the degree of beam-wave interaction） impact on couplings between cavities. By optimizing structure of IRK, this paper have high order mode oscillation restrained under the condition of minimal effect on output mi- crowave power. Finally, under excitation of injection microwave with power of 10 kW and frequency of 2.88 GHz, an output microwave with power 3.7 GW, gain 56 dB and efficiency 22 % in simulation has been achieved which effectively restrained the high-mode oscillation.