Synchrotron radiation inside a dielectric cylinder

TL;DR

This paper analyzes the electromagnetic radiation generated by a charged particle rotating inside a dielectric cylinder, deriving field expressions, evaluating radiation intensity, and demonstrating how the cylinder can significantly enhance synchrotron radiation.

Contribution

It provides new analytical expressions for bound modes of radiation inside and outside the cylinder and compares different methods for calculating radiation intensity.

Findings

The dielectric cylinder can greatly increase synchrotron radiation intensity.

Derived explicit formulas for electromagnetic fields of bound modes.

Showed the relation between work done on the charge and energy flux for radiation assessment.

Abstract

We investigate the electromagnetic fields generated by a charged particle rotating inside a dielectric cylinder immersed into a homogeneous medium. The expressions for the bound modes of the radiation field are derived in both interior and exterior regions. The radiation intensity for the modes propagating inside the cylinder is evaluated by using two different ways: by evaluating the work done by the radiation field on the charge and by evaluating the energy flux through the cross-section of the cylinder. The relation between these two quantities is discussed. We investigate the relative contributions of the bound modes and the modes propagating at large distances from the cylinder to the total radiation intensity. Numerical examples are given for a dielectric cylinder in the vacuum. It is shown that the presence of the cylinder can lead to the considerable increase of the synchrotron radiation intensity.