Design and construction of a Compact Infrared Free Electron Laser CIRFEL

The 5-15 micron Grumman Compact Infra Red Free Electron Laser CIRFEL which will produce extremely short pulses of tunable radiation under construction is described. Electron pulses are produced at a repetition rate of up to 10 Hz by the illumination of a single crystal <001> LaB/sub 6/ photocathode with a photon injector, a 6-10 psec, 349 nm (frequency tripled Nd-YLF) laser mode locked to the 20th subharmonic of 2856 MHz. Photoelectrons are further accelerated and guided to the superconducting microwiggler by a robust beam transport system through an achromatic bend. The /spl sim/10 MeV electrons interact with the optical radiation inside a near symmetric laser cavity. The FEL output will be coupled out through a hole in one of the cavity mirrors. The CIRFEL system is expected to be delivered in 1994.<>