The level structure of several Zr isotopes near $A=94\mathrm{}{(}^{92,93,94,95}\mathrm{Zr})$ has been studied in the fission of the compound nucleus ${}^{197}\mathrm{Pb},$ formed in the ${}^{24}\mathrm{Mg}{+}^{173}\mathrm{Yb}$ reaction at ${E(}^{24}\mathrm{Mg})=134.5\mathrm{}\hspace{0.5em}\mathrm{MeV}.$ Sequences of $\gamma$-ray transitions, observed in coincidence with known transitions in the complementary Mo fragments, have been newly assigned to ${}^{93,95}\mathrm{Zr}.$ The previously known level scheme of ${}^{94}\mathrm{Zr}$ has been considerably extended to higher excitations, and exhibits structural similarities to the level scheme of ${}^{92}\mathrm{Zr}$ up to spin $10ħ.$ The level schemes of ${}^{93}\mathrm{Zr}$ and ${}^{95}\mathrm{Zr}$ can be generally interpreted as the coupling of a $d_{5/2}$ neutron to the levels of ${}^{92,94}\mathrm{Zr}$ and ${}^{96}\mathrm{Zr},$ respectively. The observed experimental states are compared with theoretical shell-model calculations.

• Received 29 October 2001

DOI:https://doi.org/10.1103/PhysRevC.65.044303