Reversed Cherenkov-transition radiation in a waveguide partly filled with an anisotropic dispersive medium

We analyze the electromagnetic field of a bunch that moves uniformly in a circular metal waveguide and crosses a boundary between a vacuum area and an area filled with an anisotropic dispersive nonmagnetic medium. The medium is characterized by the diagonal dielectric permittivity tensor with components possessing frequency dispersion of plasma types. The investigation of the waveguide mode components is performed with the methods of the complex variable function theory. It is shown that in compliance with the parameters of the medium, Cherenkov radiation (CR) generated in the filled area of the waveguide can have reversed direction in relation to the bunch motion. CR can penetrate into the vacuum area of the waveguide, that is, the intensive reversed Cherenkov-transition radiation (RCTR) can be generated. The main properties of this radiation are described, and essential differences from the RCTR in the case of isotropic left-handed medium are revealed.

Automated summary

This study analyzes the electromagnetic field of a bunch moving uniformly in a circular metal waveguide and crossing a boundary between a vacuum area and an anisotropic dispersive nonmagnetic medium. It is found that Cherenkov radiation in the filled area of the waveguide can have reversed direction in relation to the bunch motion, leading to the generation of intensive reversed Cherenkov-transition radiation (RCTR). The main properties of this radiation are described, highlighting essential differences from RCTR in the case of isotropic left-handed medium.