高增益S波段相对论速调管的3D研究

在相对论速调管放大器的研究，非工作模的激发是影响器件正常工作的一个重要因素，尤其是高增益情况，这些非工作模在实际结构中还包含非对称模式．同时在相对论速调管放大器的结构中，其输入和输出部分不可避免地要引入3D结构，因此依据2D理论或2DPIC模拟得到的结果不能满足实际结构的实验需要．论文依据2DPIC设计的高增益s波段相对论速调管放大器模型进行3D研究，研究了输入、输出部分中3D结构对束波互作用的影响，通过3DPIC模拟排除了2DPIC模拟中不能反映的非对称模式的影响，验证了3D冷腔分析结果，实现了2DPIC的模拟结果：电子束参数为流强5kA、电子能量600kV，注入微波功率0．88kW、模拟微波输出功率0．57GW，相应增益为6．48×10^5．

3D design of a high-gain S-band relativistic klystron amplifier

The excitation of non-working modes is a very important factor affecting a relativistic klystron amplifier, especially the case of high-gain ones, and non-symmetry modes are also included. Meanwhile 3D structures cannot be avoided for the input and out put cavities in a relativistic klystron amplifier. Results from 2D theoretical analysis or 2D PIC simulation cannot meet the experiment＇s requirements. 3D study is carried out based on a high-gain relativistic amplifier structure obtained from 2D PIC simulation. Influence of 3D structure in the input and output cavity is carefully studied from beam-wave interaction. 3D PIC simulation is carried out, the excitation of non-symmetric modes is not observed, analysis of 3D structure is verified, and 2D PIC simulation results is also obtained： the rf output power is 0.57 GW with the beam of 5 kA and 600 kV when input power is 0.88 kW, and the corresponding gain is 6.48×10^5.