NIST-NRL free-electron laser facility

A free-electron laser facility (FEL) is being constructed at the National Institute of Standards and Technology (NIST) in collaboration with the Naval Research Laboratory (NRL) . The FEL will be driven by the electron beam from the NIST racetrack microtron (RTM). The anticipated performance of the FEL is: (1) wavelength variability from 200 run to 10 tim; (2) continuous train of 3-ps pulses at 66 MHz; and (3) average power of 10 W to 200 W. This excellent performance will be achieved primarily because of the unique characteristics of the RTM. This accelerator will provide a continuously pulsed electron beam with high brightness and low energy spread at energies from 17 MeV to 185 MeV. For FEL operation high peak current is required and a new injector for this purpose has been designed. The undulator for the project is 3.64-m long with 130 periods and a peak field of 0.54 T. The construction of the undulator is nearly complete and delivery is expected shortly. The 9-m optical cavity has been designed and is under construction. An experimental area is being prepared for FEL users which will have up to six stations. Initial operation of the FEL is scheduled for 1991. The NIST-NRL FEL will provide a powerful, tunable light source for research in biomedicine, materials science , physics , and chemistry.