FEL/Duke University, Durham, North Carolina
TUNL, Durham, North Carolina
Funding: This work is supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086 and by US Department of Energy grant DE-FG02-01ER41175.
Since 2008, the upgraded High Intensity Gamma-ray Source (HIGS) at the Duke FEL Lab has provided users with gamma beams of unprecedented quality for scientific research. The recently completed accelerator upgrades include a HOM-damped RF cavity, a full-energy top-off booster injector, redesigned storage ring straight sections, and two new FELs. The HIGS facility is now capable of producing a high intensity gamma beam in a wide energy range (1 - 100 MeV) using commercial FEL mirrors. It has achieved an exceptionally high flux, up to ~1010 g/s total (< 20 MeV), making it the world's most powerful Compton gamma source. It produces almost 100% polarized gammas, either linear or circular. At the HIGS, the gamma energy can be changed rapidly within a factor of three in minutes. Operated by Triangle Universities Nuclear Laboratory since summer 2008, the HIGS is a dedicated Compton gamma source, capable of producing more than 2,000 h of gamma beam time per year with a five-day, two-shift schedule. Future development at the HIGS includes higher energy gamma beams toward the pion threshold and a rapid switch of circular polarization.
