The investigation of wake
fields, which are excited in a dielectric waveguide by relativistic electron
bunch, is interesting for both high-gradient method of acceleration of charged
particle and generation of microwave radiation. In the given paper the processes
of excitation of wake field in cylindrical dielectric waveguide are investigated
theoretically and numerically. Both linear and non-linear process stages are
considered. The multimode distribution (50 harmonics) with large value of
permittivity εd ~10 leads to concentration of
electric field as a set of thin peaks of different polarity, which follow along
system axis with period that corresponds to wavelength of first harmonic, and
the amplitude of resulting field exceed many times that of the base mode. The
accounting of particles displacement in arising field leads to the decrease of
amplitude of active field and widening of peaks. Moreover the radial
displacement of particles provides a restriction on the effective length of
decelerating system because particles of a bunch hit walls of the waveguide
system.
