High-spin g factors and proton alignment in 180,182,184Pt

The average g factors of high-spin states in 180,182,184 Pt were measured by the transient-field technique. In all three isotopes the quasicontinuum g factor at an angular momentum of ∼20ℏ is 〈 g 〉∼0.37. This contrasts with similar measurements on other nuclei that have 70⩽ Z ⩽80, where typical values of 〈 g 〉∼0.22 have been attributed to the influence of quasineutron alignments. Evidently proton and neutron configurations are about equally important at high spin in the Pt isotopes near mid-shell. This inference is consistent with the discrete spectroscopy, including the contention, supported by g K − g R values, that h 9/2 proton pairs align along with the i 13/2 neutrons at rotational frequencies of ℏ ω ≈0.3 MeV in 184 Pt. Links between the quasicontinuum g factors and features in the discrete spectroscopy are explored by comparing and contrasting the behavior of 184 Pt and 166 Hf.