Theory of wakefields excited by an off-axis drive bunch in a plasma–dielectric waveguide

A linear theory of wakefield excitation by a drive electron bunch in a plasma–dielectric accelerating structure has been constructed for the case of off-axis bunch injection. The structure under investigation is a round dielectric-loaded metal waveguide with a channel for charged particles, filled with homogeneous cold plasma. The developed theory was used to investigate the spatial distribution of the bunch-excited transverse wakefield components, which act on the drive electron bunch. The numerical simulations using the particle-in-cell method have confirmed the predictions of the linear theory in terms of transverse drive bunch dynamics. The numerical analysis has shown stable drive bunch transport through the plasma–dielectric accelerating structure compared with the corresponding dielectric-loaded structure.