Peculiarities of electromagnetic field oscillations of a charged particle rotating about a conductive ball

Abstract

The paper investigates some characteristic features of the electromagnetic field of a relativistic charged particle that uniformly rotatesabout a conductive ball in its equatorial plane. It is assumed that the braking of the particle due to radiation is compensatedby an external influence (e.g. the electric force) that compels the particle to turn uniformly in a circle. The magnetic permittivityof the ball is assumed to be one. The work is based on the corresponding exact analytic solutions of Maxwell’s equations. The generalizedDrude-Lorentz-Sommerfeld formula for the dielectric function of the conductive ball is used in numerical calculations.It is shown that localized oscillations of a high-amplitude electromagnetic field can be generated at a given harmonic inside the ballat a certain (resonant) particle rotation frequency at a small distance from the surface of the ball. Herewith, at large distances fromthe trajectory of the particle, these localized oscillations are accompanied by intense radiation at the same harmonic, which is manytimes more intense than the analogous radiation in the case when the ball is absent.The possibilities of using this phenomenon to develop sources of quasi-monochromatic electromagnetic radiation in the range fromgiga- to terra hertz frequencies are discussed.