High-efficiency broadband THz emission via diffraction-radiation cavity

Abstract

Accelerator-based terahertz (THz) radiation has been expected to realize a high-power broadband source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme of coherent diffraction-radiation in an optical cavity layout is proposed. The scheme's stimulated radiation process between bunches can greatly enhance the efficiency of the radiation emission. We performed an experiment with a superconducting linac constructed as an energy recovery linac (ERL) test facility. The electron beam passes through small holes in the cavity mirrors without being destroyed. A sharp THz resonance signal, which indicates broadband stimulated radiation correlated with beam deceleration, was observed while scanning the round-trip length of the cavity. This observation proves the efficient beam-to-radiation energy conversion due to the stimulated radiation process.

arXiv comment13 pages , 20 figures

References in corpus (4)

• Transmission of Megawatt Relativistic Electron Beams Through Millimeter Apertures
• Observation of the Stimulated Coherent Diffraction Radiation in an Open Resonator at LUCX Facility
• Stimulated excitation of an optical cavity by a multi-bunch electron beam via coherent diffraction radiation process
• Beam tuning and bunch length measurement in the bunch compression operation at the cERL