Radiation of Surface Polaritons in Cylindrical Waveguides

We investigate the radiation of surface polaritons in a cylindrical waveguide by a charged particle. Two types of motion of the latter are considered: a particle moving parallel to the axis of the cylinder and a particle rotating around the cylinder. The general case is discussed when the cylinder is immersed in a homogeneous medium. Exact expressions are provided for the radiation intensity on a given mode of the cylindrical waveguide. The radiation of surface polaritons is present in the spectral range where the dielectric permittivities of the cylinder and surrounding medium have opposite signs and there is no velocity threshold for their generation. The spectral range of the emitted surface polaritons becomes narrower with decreasing energy of the particle.