折叠波导行波管注波互作用过程分析新方法

A New Analysis Method for Beam-Wave Interaction in Folded Waveguide TWTs

本文提出了折叠波导行波管注波互作用过程分析新方法。首先引入间隙功率流密度幅值、间隙产生功率流参量、间隙放大率参量、注波相位差的定义,然后以W波段折叠波导行波管为例,基于CST PIC数值模拟,利用该方法对折叠波导行波管的注波互作用物理过程进行分析,论述了间隙放大率参量曲线的物理意义,指出相速最佳起跳点位于从第二线性放大区进入非线性放大区的位置,通过对比不同起跳位置的仿真结果,验证了该方法的合理性与正确性,可以进一步研究相速再同步技术,提高互作用效率。

A new method is presented to analyze beam-wave interaction in folded waveguide TWT in this paper.The definition of amplitude of power flow density in gap,the power flow parameter produced in gap,the magnification of power flow in gap and phase difference of beam and wave is introduced.A W-band folded waveguide TWT is taken to illustrate the physical process of beam-wave interaction based on numerical simulation using CST PIC Solver.The physical meaning of magnification of power flow in gap is discussed.The research indicates that the optimal starting point for velocity taper is located on the border of linear region II and nonlinear region II.The simulation results of different starting points for velocity taper validate the method faithful and practical.The new method will be adopted to study phase velocity resynchronization in depth so as to improve electron efficiency of folded waveguide TWTs in the future.