Influence analysis of transient response and dispersion characteristics in traveling-wave accelerator via equivalent circuit

摘要: In this study, the transient response and dispersion characteristics in a traveling-wave accelerator are analyzed via an equivalent circuit method. A SLAC-like constant-gradient traveling-wave Linac is used as an example to construct a cascaded equivalent circuit model. Different transient response solution methods, including dynamic circuit simulation, iterative solving of circuit differential equations, and quasi-steady-state solutions of differential equations, are compared, and consistent results are obtained. The influence of dispersion on the transient response is analyzed from the perspectives of envelope oscillations and the transient process. A compensation scheme for dispersion is proposed using the multi-objective genetic algorithm NSGA-II. The beam load is also compensated by adding a ramp to the initial input pulse. The results show that the equivalent circuit model can effectively analyze the transient response in the Linac, and the proposed compensation scheme can mitigate the dispersion effects. This research can provide guidance for the design and tuning of the RF feedforward system.