THz wakefield radiation generation via dielectric Bragg waveguide

In this paper, the wakefield response of a dielectric Bragg waveguide (DBW) driven by electron bunches is reported. The structure comprises of a cylindrical dielectric lined waveguide with the metallic coating replaced by a Bragg reflector. Starting from the theory of planar Bragg reflectors, a new analytical approach to structural design is derived via numerical simulations. By adjusting the layer thickness condition and the number of layers, the DWB can be optimised to give the strongest wakefield response. The wakefields can be used for the direct excitation of high-power THz radiation or for high-gradient acceleration.