Spectroscopy of Nb90 at high spin

Abstract

Excited states of Nb90 were investigated via prompt and delayed γ decays and the recoil-isomer tagging technique. The level scheme of Nb90 has been extended up to J=19 and Ex=8.4 MeV. Half-lives of the 11- and 17/2- isomeric levels in Nb90,91 were measured to be 0.47±0.01 and 3.3±0.4 μs, respectively. The results are compared with the predictions of large-basis shell model calculations. The effects of truncation of the valence model space on the calculated results are discussed. © 2005 The American Physical Society.