S波段相对论速调管放大器同轴输出腔的数值模拟

Numerical simulations of coaxial output cavity of S-band relativistic klystron amplifier

介绍了S波段强流相对论速调管放大器(RKA)同轴输出腔内束波转换效率和腔主要参数的计算、微波提取的粒子模拟和优化以及实验。模拟计算时,采用单间隙的同轴输出腔,束压580 kV、束流4 kA的环行电子束,基波调制深度为80%,利用3维粒子程序得到约500 MW的微波输出功率,效率21.5%。将该模拟结果应用于实验的设计,实验中采用束压550 kV、束流4 kA的电子束得到功率500 MW、脉宽120 ns的输出微波,束波转换效率22.7%,实验结果与模拟结果吻合较好。

The calculation of coaxial output cavities, simulation of microwave extraction from a modulated intense relativistic electron beams, optimization on beams and output cavity geometry parameters, as well as the experiments of microwave extraction for an S-band long-pulse-intense-current relativistic klystron amplifier are described in this paper. Applying a three dimensional code, an output power of 500 MW is obtained. The efficiency is about 21.5%. In experiments, a hollow electron beam of 550 kV, 4 kA generates an electron beam with modulated current of 3.2 kA after idler cavity gap. About 500 MW RF power is obtained. The efficiency is about 22.7 %. The results of simulation agree well with the experimental results.