90Zr revisited: Level structure, lifetimes, and transition rates from (n,n'γ) reaction measurements

The low-energy structure of spherical nuclei have been studied with a variety of probes, but recent advances in (n,n'γ) spectroscopic techniques have permitted study of nuclei in detail at increasingly higher excitation energies. The authors have revisited the N=50 region to study the nuclei 90Zr and 88Sr by observing γ rays emitted following the inelastic neutron scattering reaction. For En < 7.5 MeV, the level structure of 90Zr has been reinvestigated; a new level scheme, lifetimes, and extracted transition rates are presented, and the possibility of collective modes in this spherical nucleus are examined