TIME AND FREQUENCY-DOMAIN ANALYSIS OF SUPERRADIANT COHERENT SYNCHROTRON-RADIATION IN A WAVE-GUIDE FREE-ELECTRON LASER

The coherent synchrotron radiation process in a waveguide is theoretic ally investigated. A single, short bunch propagating through a wiggler is considered. In a waveguide, two very distinct regimes are possible . At grazing, where the beam velocity matches the wave group velocity, the bunch emits a single, ultrashort chirped pulse whose duration is determined by the interaction bandwidth and the waveguide dispersion. Away from grazing, where slippage dominates, two distinct pulses are r adiated at the Doppler upshifted and downshifted frequencies. Both the time and frequency domain expressions for the radiation characteristi cs are derived.