The static quadrupole moment of the first excited state of 60Ni

Abstract

From measurements of the Coulomb excitation of the 1.3325 MeV first excited state in 60Ni using sulphur and oxygen ions, it has been possible to obtain a value for the static quadrupole moment of this state. Analysis of the data using a coupled-channel computer code yields the results: B(E2; 0 + → 2 +) = 0.0914±0.0020 ( e · b) 2 and a first excited state static quadrupole moment of Q = 0.00±0.13 e · b. These results are in good agreement with both microscopic- and macroscopic-model predictions. Uncertainty in the signs of the interference terms due to virtual excitation through higher excited 2 + states contributed 40% of the error assigned to Q. The 16O scattering data deviated markedly from Coulomb excitation theory for incident energies above 30 MeV presumably due to the occurrence of nuclear interactions. These deviations were indistinguishable from those produced by the reorientation effect assuming a large negative static quadrupole moment for the first excited state.