Elliptical and circular annular solid electron beam for excitation of hybrid modes in the plasma combined circular and elliptical waveguides

For two new configurations presented and by considering annular solid electron beam with background plasma the growth rates of the hybrid modes and the dispersion relation of electromagnetic waves propagating are studied. The interaction of elliptical and circular annular solid electron beams with plasma is investigated that it occurs microwave radiation generation dependent of configuration dimensions. The structures are including metallic elliptical(circular) waveguide with elliptical(circular) dielectric cladding and a core having a circular(elliptical) dielectric rod in center that it is surround by circular(elliptical)annular plasma and a circular(elliptical)annular relativistic electron beam is injected in to plasma. The electromagnetic fields components in each of regions in the considered configurations are calculated. By applying the boundary conditions dispersion relation and operating frequency are obtained. Furthermore for another case that it is applied an infinite magnetic field to considered structures,the problem is investigated. Numerical computations are made and results are graphically presented.