S波段多注相对论速调管放大器的数值模拟

摘要

利用3维电磁场与粒子模拟软件对S波段多注相对论速调管放大器进行了分析设计和模拟计算.通过对谐振腔本征模的计算确定腔体的冷腔高频特性,采用3维的粒子模拟软件(PIC)模拟分析速调管各腔及整管的束波互作用过程.模拟结果表明:通过引入同轴谐振腔结构,使电子注不必集中在谐振腔中心通过,降低了电场不均性对束波互作用的不利影响；通过引入多电子注,电子在相对较低的轴向聚焦磁场下依然拥有较高的通过率,降低了速调管对聚焦磁场的要求.模拟中采用3个同轴谐振腔进行束波互作用,在输入电压700 kV、束流5.8 kA和聚焦磁场0.4T的情况下,得到了功率1.4 GW的输出微波,效率为35％.%This paper analyzes an S-band relativistic multiple-beam klystron amplifier with three-dimension electromagnetic codes, including the high frequency characteristics analysis and beam-wave interaction studies. The simulation results show that the adoption of coaxial resonant cavity can reduce the adverse effect of electric field asymmetry in the cavity, for the beams do not have to concentrate at the center to pass through the cavity; the use of multiple-beam can reduce the magnetic field strength for beam transport to about 0. 4 T. With a 700 kV, 5. 8 kA electron beam under 0. 4 T magnetic field, the amplifier with three coaxial resonant cavities has a peak pulsed output power of 1. 4 GW with a corresponding electronic efficiency of 35%.