High resolution spectroscopy of the giant resonance in the 16O(γ,abs) reaction

The characteristics of the nuclear photo-absorption spectroscopy using the laser Compton scattering (LCS) photons and the high-resolution high-energy photon spectrometer (HHS) are presented in this paper. The maximum energy of a LCS photon was increased up to 30MeV, and the response functions of the HHS were improved. By taking advantage of these achievements, the 16 O(γ,abs) cross section was measured in the giant resonance region, that is, 20 to 25MeV. The preliminary result with the energy resolution of about 0.1% is presented and compared with the preceding data.