Fine structure in a alpha decay of 188, 192Po

Abstract

The α decay of 188,192Po has been reexamined in order to probe the 0+ states in the daughter nuclei 184,188Pb that can be associated with coexisting spherical, oblate, and∕or prolate configurations. Improved values were measured for the excitation energy and the feeding α-decay intensity of the 0+2state in 184,188Pb and conflicting results on the 0+3 state in 188Pb were clarified. All known cases of fine structure in the α decay of the even-even Po nuclei are reviewed. The reduced α-decay width systematics combined with potential-energy-surface calculations confirm the onset of deformation in the ground state of the polonium nuclei around the neutron midshell. An isomeric state with a half-life of 580(100)ns has been identified in 192Po.