A theory of the beam-wave interaction for a dielectric Cherenkov maser operating in nonaxisymmetric mode

Summary form only given. Linear and nonlinear theory has been formulated for Cherenkov interaction between a thin annular relativistic electron beam and the arbitrary nonaxisymmetric mode of a circular dielectric-lined waveguide. The approach is based on the separation of AC space charge fields and the synchronous wave field. Expressions for the beam-wave coupling coefficient and the AC space charge depression coefficient in the nonaxisymmetric case have been derived. The nonlinear dynamics of the beam-wave interaction essentially differs from the axisymmetric case. The bunching occurs differently also for a rotating mode and a mode with a fixed azimuthal field structure.