High-gain cerenkov free-electron laser at far infrared wavelengths

The small-signal gain is derived for a Cerenkov free-electron laser operating in the collective beam limit. The device consists of two dielectrically lined parallel plates driven by a cold, relativistic electron beam. The dependence of the output wavelength on the resonator parameters and the electron beam energy is examined with particular attention devoted to device operation in the far infrared and submillimeter portion of the electromagnetic spectrum at moderate electron beam energies (
\gamma < 3
).