Proton states in193Ir and195Ir populated via the (α) reaction

The nuclear structures of193Ir and195Ir have been studied using the194Pt(t, α) and196Pt(t, α) reactions. Levels up to ∼2MeV in excitation energy were studied with a resolution of ∼13keV (FWHM) and spectroscopic strengths were extracted. The low-lying states in193Ir have been interpreted in terms of both the Nilsson and the rotation-vibration models including Coriolis, particle-vibration and rotation-vibrational couplings. The previously assigned 3/2+ [402], 11/2− [505], 1/2+[400] and 1/2+[411] bands were populated and candidates for the 5/2+ [402] and 7/2+ [404] bandheads were observed. TheK0 +2 gamma vibration based on the ground state was populated because it is mixed with the 7/2+ [404] state. Surprisingly, there was no significant difference between the stripping and pick-up strengths for the low-lying states in193Ir, suggesting that the equilibrium nuclear shape of193Ir has large overlaps with the shapes of both192Os and194Pt. The nuclear level structure of195Ir appears to be similar to those of the lighter iridium isotopes.