High-spin states of the doubly odd nucleus 178Ta

Abstract The properties of levels in 178 Ta have been investigated via the reactions 176 Lu(α, 2n) 178 Ta, 178 Hf(d, 2n) 178 Ta and 178 Hf(p, n) 178 Ta. Energies, intensities, angular distributions, prompt and delayed coincidence relations of γ-ray transitions, lifetimes of isomeric levels as well as conversion electron spectra have been measured. The high-spin states observed have been assigned to rotational bands built on proton-neutron two-quasiparticle excitations with K π = 6 − , 7 − , (8) + and 9 − , respectively. A high-spin isomer with a half-life of T 1 2 = 60 ms has been found at 1470.6 keV and assigned as a 15 − four-quasiparticle state. Nilsson configurations are proposed for most of the levels.