The high intensity γ-ray source (HIγS) and recent results

The high intensity γ-ray source (HIγS) utilizes intra-cavity backscattering of free electron laser photons from the Duke electron storage ring to produce a unique monoenergetic beam of high-flux γ-rays with high polarization and selectable energy resolution. At present, γ-ray beams with energies from 2 to 58 MeV are available with intensities as high as 105-5 × 106 γ/s, energy spreads of 3% or better, and nearly 100% linear polarization. The quality and intensity of the γ-ray beams at HIγS are responsible for the unprecedented performance of this facility in a broad range of research programs in nuclear structure, nuclear astrophysics and nuclear applications. Recent results from excitation of isomeric states in (γ, n) reactions and parity assignments of dipole states determined via the (γ, γ′) reaction are presented.