Abstract
The E0 transition strength in the 2(2)(+) > 2(1)(+) transitions of Ni-58,Ni-60,Ni-62 have been determined for the first time following a series of measurements at the Australian National University (ANU) and the University of Kentucky (UK). The CAESAR Compton-suppressed HPGe array and the Super-e solenoid at ANU were used to measure the delta(E2/M1) mixing ratio and internal conversion coefficient of each transition following inelastic proton scattering. Level half-lives, delta(E2/M1) mixing ratios and y-ray branching ratios were measured at UK following inelastic neutron scattering. The new spectroscopic information was used to determine the E0 strengths. These are the first 2(+) -> 2(+) E0 transition strengths measured in nuclei with spherical ground states and the E0 component is found to be unexpectedly large; in fact, these are amongst the largest E0 transition strengths in medium and heavy nuclei reported to date. (C) 2018 The Author(s). Published by Elsevier B.V.