Design of TEAFEL, a recirculating 3–12 MeV electron beam system for FELs

Abstract The design of a 6 and 12 MeV electrostatic-accelerator FEL is presented. The system will use recirculation of the electron beam in order to obtain ampere level currents. Energy variability, coupled with the use of short-period undulators, will allow continuous tunability of the system over wavelengths between 8 and 120 μm.