Transition radiation at the boundary of a chiral isotropic medium.

This study analyzes the radiation produced by a point charge intersecting the interface between a vacuum and a chiral isotropic medium. We deduce analytical expressions for the Fourier components of an electromagnetic field in both vacuum and medium for arbitrary charge velocity. The main focus is on investigating the far field in a vacuum.

Radiation of charged-particle bunches passing perpendicularly by the edge of a semi-infinite planar wire structure.

The radiation of a charged-particle bunch moving perpendicularly to a semi-infinite plane grid composed of thin parallel wires is analyzed using the method of averaged boundary conditions (the period of the grid is assumed to be much less than the wavelengths under investigation). We perform an analysis of the volume radiation and surface waves generated by a bunch of finite length. It is shown that the patterns of the volume radiation fundamentally differ from those that arise in the case of an infinite grid.

Dielectric concentrator for Cherenkov radiation.

We report on a dielectric target that concentrates Cherenkov radiation into a small spatial area. In contrast to traditional devices, this target can focus almost all of the radiation without using additional lenses or mirrors. We consider the case where radiation is produced by a point charge moving along the axis of a cylindrical channel inside an axially symmetrical target.

Radiation of charges moving along the boundary of a wire metamaterial.

The electromagnetic fields of charges moving along the boundary of a "wire metamaterial" perpendicularly to the wires are investigated. The metamaterial under consideration represents a volume-periodic structure of thin parallel wires located in a square lattice. This structure is described by an effective permittivity tensor and exhibits both spatial and frequency dispersion.

Electromagnetic field of a charge moving in a chiral isotropic medium.

We analyze the electromagnetic field generated by a point charge moving with a constant velocity in an isotropic chiral medium. We work in the frame of the Condon dispersion model for the weak chirality and ultrarelativistic motion of the charge. We show that the field of a moving charge contains two low-frequency wave processes with right- and left-hand circular polarizations and a high-frequency wave process with a right-hand polarization.

Approximate method for calculating the radiation from a moving charge in the presence of a complex object.

An approximate method for calculating the radiation from a moving charge in the presence of a dielectric object is developed. The method is composed of two steps. The first step is calculation of the field in the medium without considering the external boundaries of the object, and the second step is an approximate (ray-optical) calculation of the wave propagation outside the object.

Electromagnetic field of a charge moving in a cold magnetized plasma.

The present paper addresses the electromagnetic field generated by a point charge or a small charged particle bunch moving with constant velocity in a cold magnetized plasma, along the external magnetic field. Attention is focused on the case of ultrarelativistic motion. The field surrounding the point charge is investigated both analytically and numerically.

Nondivergent Cherenkov radiation in a wire metamaterial.

The electromagnetic radiation of a charge moving in an infinite 3D structure made of parallel wires is considered. The periods of the structure are assumed to be small; therefore, it can be described by an effective permittivity tensor. The charge velocity is perpendicular to the wires.

Electromagnetic field of a charge traveling into an anisotropic medium.

We analyze the electromagnetic field generated by a point charge intersecting the interface between vacuum and a nonmagnetic anisotropic medium with a plasma-type dispersion of the dielectric permittivity tensor. After penetrating the medium, the charge moves along its main axis. The total field is presented as a sum of a self-field (i.

Electromagnetic field of a charge intersecting a cold plasma boundary in a waveguide.

We analyze the electromagnetic field of a charge crossing a boundary between a vacuum and cold plasma in a waveguide. We obtain exact expressions for the field components and the spectral density of the transition radiation. With the steepest descent technique, we investigate the field components.

Reversed Cherenkov-transition radiation by a charge crossing a left-handed medium boundary.

We analyze the radiation from a charged particle crossing the boundary between an ordinary medium and a "left-handed" metamaterial. We obtain exact and approximate expressions for the field components and develop algorithms for their computation. The spatial radiation in this system can be separated into three distinct components, corresponding to ordinary transition radiation having a relatively large magnitude, Cherenkov radiation, and reversed Cherenkov-transition radiation (RCTR).

Vavilov-Cherenkov radiation in passive and active media with complex resonant dispersion.

Some of the problems with the theory of moving charge radiation in media with frequency dispersion are analyzed. First, some general properties of the integrals for field components are described. The results are applied to the cases of passive and active media.