First lasing of the Jefferson Lab IR Demo FEL
Benson S., Biallas G., Bohn C., Douglas D., Dylla HF., Evans R., Fugitt J., Hill R., Jordan K., Krafft G., Legg R., Li R., Merminga L., Neil GR., Oepts D., Piot P., Preble J., Shinn M., Siggins T., Walker R., Yunn B.
As reported in previous work, Jefferson Lab is building a free-electron laser capable of generating a continuous wave kilowatt laser beam. The driver-accelerator consists of a superconducting, energy-recovery accelerator. The initial stage of the program was to produce over 100 W of average power with no recirculation. In order to provide maximum gain the initial wavelength was chosen to be 5 μm and the initial beam energy was chosen to be 38.5 MeV. On June 17, 1998, the laser produced 155 W cw power at the laser output with a 98% reflective output coupler. On July 28th, 311 W cw power was obtained using a 90% reflective output coupler. A summary of the commissioning activities to date as well as some novel lasing results will be summarized in this paper. Present work is concentrated on optimizing lasing at 5 μm, obtaining lasing at 3 μm, and commissioning the recirculation transport in preparation for kilowatt lasing this fall.