RIBF Nuclear Physics Seminar 130th: Structural evolution of neutron-rich nuclei around 108Zr

by Dr Toshiyuki SUMIKAMA (Tokyo University of Science)

Tuesday 10 Jan 2012, 16:00 → 17:30 Asia/Tokyo

RIBF Conference Hall

Neutron-rich Zr (Z = 40) isotopes are known to be suddenly deformed at N = 60 and quadrupole deformation reaches around 0.4. While the deformed sub-shell closure is predicted at N = 60, 62, and 64, the relation between the deformation evolution and the deformed sub-shell closure is unknown, because the deformation evolution beyond N = 64 has not been measured. We measured the low-lying state energies of 106Zr and 108Zr to investigate the deformation evolution. The secondary beam of the neutron-rich Zr and Y (Z = 39) isotopes was produced as in-flight fission fragments of the 238U beam with 345 MeV/nucleon at RI Beam Factory, RIKEN. We measured the beta-delayed gamma rays from 106Y, which decays to 106Zr, and the gamma rays from a newly-discovered isomer of 108Zr. We will show experimental results and discuss about the deformed sub-shell closure at N = 64, and a possible structure of 108Zr isomer. The structure of Nb and Mo isotopes will be also discussed.