Cerenkov radiation from bunched electron beams

Abstract

Cerenkov radiation is calculated for electron beams which exceed the velocity of radiation in a non dispersive dielectric medium. The electron beam is assumed to be bunched as emitted from a travelling wave accelerator, and the emission region is assumed to be finite. Predictions include: emission at harmonics of the bunch rate; coherence of radiation at low frequencies; smearing of the emission angle for finite emission regions; and explicit evaluation of power spectrum in terms of bunch dimensions. The results apply to microwave emission from fast electrons in air or other dielectrics. (Author)