Motion-induced radiation from electrons moving in Maxwell's fish-eye

TL;DR

This paper investigates how electrons interacting with Maxwell's fish-eye sphere generate radiation through a combination of Cerenkov and transition radiation, offering new insights into converting evanescent waves into detectable radiation.

Contribution

It introduces a novel study of electron-induced radiation in Maxwell's fish-eye, combining Cerenkov and transition radiation mechanisms, expanding understanding of wave-to-radiation conversion.

Findings

Radiation results from a mix of Cerenkov and transition radiation.

Electron interaction with Maxwell's fish-eye can produce detectable radiation.

Potential new methods for transferring evanescent waves to radiation.

Abstract

In \u{C}erenkov radiation and transition radiation, evanescent wave from motion of charged particles transfers into radiation coherently. However, such dissipative motion-induced radiations require particles to move faster than light in medium or to encounter velocity transition to pump energy. Inspired by a method to detect cloak by observing radiation of a fast-moving electron bunch going through it by Zhang {\itshape et al.}, we study the generation of electron-induced radiation from electrons' interaction with Maxwell's fish-eye sphere. Our calculation shows that the radiation is due to a combination of \u{C}erenkov radiation and transition radiation, which may pave the way to investigate new schemes of transferring evanescent wave to radiation.