High-spin μs isomer in Zr98

A high-spin isomer in Zr98, of half-life 1.9 (2) μs, has been observed using the Lohengrin mass spectrometer of the high-flux reactor of the Institut Laue-Langevin, Grenoble. The isomer was produced by the thermal-neutron induced fission of Pu239. Measurements at the spectrometer focal point of γ-t and γ-γ-t, relative to the arrival of a fission fragment, allowed the isomer to be identified and the level scheme constructed. The isomeric state at 6603.3 keV of excitation energy is tentatively assigned a spin and parity of (17^-) and is proposed to have a π(g_9/2²)ν(g_7/2¹h_11/2¹) configuration.