First lasing of the IR upgrade FEL at Jefferson lab
Behre C., Benson S., Biallas G., Boyce J., Curtis C., Douglas D., Dylla HF., Dillon-Townes L., Evans R., Grippo A., Gubeli J., Hardy D., Heckman J., Hernandez-Garcia C., Hiatt T., Jordan K., Merminga L., Neil G., Preble J., Rutt H., Shinn M., Siggins T., Toyokawa H., Waldman DW., Walker R., Wilson N., Yunn B., Zhang S.
We report initial lasing results from the IR Upgrade FEL at Jefferson Lab (Proceedings: 2001 Particle Accelerator Conference, IEEE, Piscataway, NJ, 2001). The electron accelerator was operated with low average current beam at 80MeV. The time structure of the beam was 120pC bunches at 4.678MHz with up to 750μs pulses at 2Hz. Lasing was established over the entire wavelength range of the mirrors (5.5-6.6μm). The detuning curve length, turn-on time, and power were in agreement with modeling results assuming a 1ps FWHM micropulse. The same model predicts over 10kW of power output with 10mA of beam and 10% output coupling, which is the ultimate design goal of the IR Upgrade FEL. The behavior of the laser while the dispersion section strength was varied was found to qualitatively match predictions. Initial CW lasing results also will be presented. © 2004 Elsevier B.V. All rights reserved.