(The) growing of microwaves in relativistic electron beam propagating through the dielectric-loaded cylindrical waveguide

Abstract

The dispersion relation for the transverse magnetic modes of a dielectricloaded, cylindrical waveguide driven by a cold relativistic electron beam is derived. Growth rates for Cerenkov cylotron instability as well as slow space-charge instability are evaluated from the dispersion relation. We examine the growth rates for Cerenkov cyclotron instability for the various values of several parameters, such as external magnetic field, thickness of dielectric material and dielectric constant. The results have shown that Cerenkov cyclotron instability should be considered for a moderate magnetic field in addition to slow space-charge instability, and that the growth rate of Cerenkov cyclotron instability depends sensitively on the thickness of dielectric material.