In-beam gamma-ray spectroscopy of odd-neutron Mo and Ru isotopes

Abstract

Levels of Mo and Ru isotopes, excited by the reactions 94Zr(α, 3n) 95Mo, 96Zr(α, 3n) 97Mo, 92Mo(α, n) 95Ru, 94Mo(α, n) 97Ru, 98Mo(α, 3n) 99Ru, and 100Mo(α, 3n) 101Ru, have been studied by in-beam γ-ray spectroscopic techniques (γ-singles spectra, beam-γ delay, γγ coincidence, and γ-ray angular distributions). A new isomer, t 1 2 = 8 ns , is found in 95Ru. Much of the new information concerns high-spin states. In 95Mo, number of these states are predicted by calculations for the configuration (πp 1 2 ) 2 (πg 9 2 ) 2 (v d 5 2 ) 3 , and most of the others can be accounted for qualitatively by inclusion of other neutron orbitals, primarily g 7 2 and h 11 2 for the high-spin states. Similar shell-model structures are inferred for some levels in 97, 99, 101Ru. In 101Ru and 99Ru we observed also sequences of high-spin, odd-parity states which can be characterized as phonon bands coupled to an 112 − particle state.