Y. Wakabayashi

Alpha-cluster dominance in the αp process in explosive hydrogen burning

1Center for Nuclear Study, University of Tokyo, Wako 351-0198, Japan 2Institute of Physics, VAST, Hanoi, Vietnam 3Japan Atomic Energy Agency, Tokai, Ibaraki 351-1195, Japan 4Department of Physics, Kyushu University, Fukuoka 812-8581, Japan 5Department of Physics, Tohoku University, Sendai 980-8578, Japan 6Department of Physics, Tsukuba University, Tsukuba 305-8571, Japan 7Faculty of Science, Yamagata University, Yamagata 990-8560, Japan 8Department of Physics, University of McMaster, Canada 9Universita di Catania and INFN-LNS, Catania, Italy 10Department of Physics, Seoul National University, Seoul, Korea 11Ewha Womans’ University, Seoul, Korea 12Institute of Modern Physics, Lanzhou, China 13Department of Physics, Chung Ang University, Seoul, Korea 14Max-Planck-Institut fur Astrophysik, D-85748 Garching, Germany

Search for spin-orbit-force reduction at 106,108Zr around r-process path

Shell gap at the magic number N = 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N = 82 and a new shell closure at N = 70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, 110Zr(Z = 40,N = 70). We performed β-γ and isomer spectroscopy at RIBF to observe low-lying states in 106,108Zr. The present results indicate a well deformed shape for 106,108Zr. The drastic reduction of the spin-orbit force most likely does not occur around 110Zr on an r-process path.

Nuclear Astrophysics Programs with Low‐Energy RI Beams at CRIB

Nuclear astrophysics activities with CNS RI beam separator (CRIB) are reported together with the present status of the CRIB facility which is supported by the AVF upgrade project for the total development of the low‐energy RIB facility. The activities include direct and indirect measurements of stellar reactions especially relevant to explosive burning processes such as nova and supernovae. Some recent results are discussed together with a scope of the facility.