Abstract
An electron radiation apparatus is provided. The electron radiation apparatus includes a beat-wave laser system generating a laser beat wave, an electron emitter emitting a density-modulated electron current induced by the laser beat wave, an electron accelerator accelerating the density-modulated electron current and generating a periodically bunched electron beam, and a radiation device receiving the periodically bunched electron beam and generating an electron radiation with a radiation frequency matched to one of the harmonics of the bunching frequency of the periodically bunched electron beam.