High spin excited states in neutron-rich nuclei ${}_{}{}^{112,114,116}{}_{}{}^{}\mathrm{Pd}$ have been investigated by measuring prompt γ rays emitted from a ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$ spontaneous fission source. Two different measurements were performed. First, γ-γ coincidence data, necessary to determine the decay schemes, were obtained by using an array of 20 Compton-suppressed Ge detectors. Second, Z identification and the enhancement of a desired neutron channel were carried out using a x-n-γ multiplicity spectrometer. Ground state bands have been extended to ${\mathit{J}}^{\mathrm{\pi }}$=${10}^{+}$ for ${}_{}{}^{112}{}_{}{}^{}\mathrm{Pd}$, and ${\mathit{J}}^{\mathrm{\pi }}$=${12}^{+}$ for ${}_{}{}^{114}{}_{}{}^{}\mathrm{Pd}$ and ${}_{}{}^{116}{}_{}{}^{}\mathrm{Pd}$. Band crossings were observed in all three isotopes. It was found from cranked shell model calculations that these backbends are due to the alignment of two ${\mathit{g}}_{9/2}$ protons. The measured energy levels were also compared with predictions of the interacting boson model.

• Received 1 March 1993

DOI:https://doi.org/10.1103/PhysRevC.48.566