Reaction O16(γ, p)N15 20.5 MeV Polarized Bremsstrahlung

Abstract

D 2 O soaked, H 2 O soaked and unsoaked emulsions were irradiated simultaneously at the characteristic angle the 20.5 MeV polarized brems-strahlung from a thin Al target in a betatron. The linear polarization of the gamma rays from 4 MeV to 6 MeV was estimated to be 31.7±5.0% observing the azimuthal angular distribution of photoprotons from deuterons. The H 2 O soaked emulsion and unsoaked one were used to study O 16 (γ, p ) reaction. The proton energy spectrum shows a structure which agrees with the earlier results except a peak at 1.1 MeV of proton energy. This peak which has never been found corresponds to the well-known resonance in N 15 ( p , γ)O 16 at 1.05 MeV of proton energy. The azimuthal angular distributions of photoprotons caused several photon energy regions were observed. From these angular distributions it is shown that a resonance at a photon energy of 17.3 MeV is E 1 transition, and the corresponding level of O 16 is considered to have J =1 - , T =1, which is in good agreement with the theoretical calculation in the intermediate coupling.