Wakefield Excitation By A Ramped Electron Bunch Train In A Plasma-Dielectric Waveguide

A linear theory of wakefield excitation by a ramped electron bunch train in a cylindrical plasma-dielectric waveguide is presented. It is shown that during an excitation process the drive bunches are in the focusing field due to the radial electric field excitation of the plasma wave. The possibility of both obtaining a high transformer ratio and focusing the drive and witness bunches is demonstrated.