S波段速调管双间隙输出腔的设计和实验研究

 介绍了S波段强流相对论速调管放大器(RKA)双间隙输出腔高频系统的设计，并利用3维粒子模拟程序模拟和优化了短脉冲强流相对论调制电子束经过双间隙输出腔后的微波提取。在束压640 kV、束流6 kA、基波调制深度80%的条件下，模拟得到功率为1.1 GW的微波，频率约为2.85 GHz，效率28%。在高频分析和粒子模拟的基础上进行了实验研究，实验中采用束压640 kV、束流6 kA的环行电子束，经过优化调节RKA参数，在中间腔后得到了约4.6 kA的基波调制电流，加上双间隙提取腔后从该RKA获得了频率为2.9 GHz、功率为1 GW、脉宽22 ns的输出微波，束波转换效率26%。

Design and investigation of S-band klystron double-gap output cavity

The design of double-gap output cavity for relativistic klystron amplifier is provided. The angle and position of support rods and gap length are described. Using a three-dimension fully electromagnetic Particle-in-Cell (PIC) code,the simulation of microwave extraction from modulated intense relativistic electron beams which pass through double-gap output cavity is investigated,and the beams and double-gap output cavity geometry parameters are optimized. An output microwave power of 1.1GW is generated by simulation,with an electron beam voltage of 640 kV,a current of 6 kA and 80% modulation depth of the fundamental wave. The efficiency is 28%. The S-band RKA double-gap output cavity was designed according to high frequency analysis and particle simulation results. Subsequently,the experiments including cold test and hot test were performed. In hot test,a hollow electron beam of 640 kV,6 kA generated an electron beam with modulated current of 4.6 kA after idler cavity gap. About 1GW RF power with a duration of 22 ns was obtained in space,and the efficiency is about 26%. The experimental results agree well with the results of high frequency analysis and particle simulation.