Photo-nuclear astrophysics in NewSUBARU γ-ray source

A laser Compton scattering (LCS)γ-ray source has been installed at an electron storage ring NewSUBARU at SPring-8. We have studied the nuclear physics using this LCS g-ray source. The half-lives of unstable isotopes, 184Re and 164Hom, produced by photo-induced reactions have been measured. These half-lives are shorter than previous recommended values by 7% and 3%, respectively. These changes of the half-lives affects to evaluation of cross-sections using the activation method. We have discussed a problem of the residual ratio of an isomer in 180Ta in supernova explosions. The unstable ground state and the metastable isomer are linked by (γ, γ') reactions. We have developed a new time-dependent model to calculate the isomer ratio in supernovae. The solar abundance of 180Ta is reproduced by the supernova neutrino process with the present calculated isomer ratio.