High-spin states of ${}^{98,99,100}\mathrm{Ru}$ have been populated using the reaction ${}^{70}\mathrm{Zn}{(}^{36}\mathrm{S},\alpha \mathrm{x}n)$ at 130 MeV. The $\gamma$ rays have been detected with the EUROGAM-2 array. New high-spin bands have been established in these nuclei and interpreted as terminating configurations using the Nilsson-Strutinsky cranking formalism. These bands were observed up to the predicted terminating states which are built from $g_{9/2}$ protons and $N=3\mathrm{}$ proton holes combined with $d_{5/2},$ $g_{7/2},$ and $h_{11/2}$ neutrons relative to a ${}^{90}\mathrm{Zr}$ core. Core-excited configurations with $N=3\mathrm{}$ proton holes have been found to play an important role. The observed high-spin states assigned as terminating show systematic behavior and provide new information on the energy spacing between the ${2d}_{5/2}$ and ${1g}_{7/2}$ neutron subshells.

• Received 12 October 1999

DOI:https://doi.org/10.1103/PhysRevC.62.044317