Radiation of a Wakefield Excited by an Electron Bunch Train in a Section of Dielectric Waveguide

摘要

The results of studies of wakefield excitation in a section of dielectric tube inserted in metal waveguide are presented. The dielectric tube is shorter than a metal waveguide. Dependences of the longitudinal electric field registered in some points of a waveguide from length of dielectric tube are presented. For PIC simulations the parameters of experimental installation "Almaz-2" were chosen. It is shown that the field radiated from the dielectric tube and recorded in vacuum part of a cylindrical waveguide has character of the sinusoid growing when increasing in length of dielectric tube. The oscillation period is equal to the half of the wavelength of E_(01) mode that is in resonance with electron bunches. Oscillating character is explained with dependence of transmission coefficient of excited waves through a dielectric plate from its width. Dependence of magnitude of the radiated field on number of the bunches injected in structure is investigated also.