Excitation of THz symmetric TM-modes in a cylindrical metallic waveguide with an axial magnetized degenerate plasma rod by an electron beam

The dispersion relation of symmetric electromagnetic TM-modes in a cylindrical metallic waveguide with a magnetized degenerate plasma column protected by an annular dielectric layer are obtained. The permissible frequency regions for slow E-modes (TM) are presented. In addition, the time growth rate for excitation of these waves by a thin annular relativistic electron beam (TAREB) is studied. The dependency of time growth rate on the strength of the external magnetic field, hole plasma frequency and accelerating voltage are investigated.