Coupling a proton and a neutron to the semidoubly magic nucleus Ni-68: A study of Cu-70 via the beta decay of Ni-70 and Cu-70
Van Roosbroeck, J × De Witte, H Gorska, M Huyse, Marc Kruglov, K Van de Vel, K Van Duppen, Piet Franchoo, S Cederkall, J Fedoseyev, VN Fynbo, H Georg, U Jonsson, O Koster, U Weissman, L Mueller, WF Mishin, VI Fedorov, D Walters, WB Smirnova, NA Van Dyck, A De Maesschalck, A Heyde, K #
American physical soc
Physical Review C vol:69 pages:1-19
The Ni-70 nucleus has been produced at the LISOL facility and its beta decay to Cu-70 has been observed. In parallel, the Cu-70 nucleus has been produced at the ISOLDE facility. A new third beta-decaying isomeric state in Cu-70 has been identified, partly with the aid of the in-source laser spectroscopy method. Its measured half-life is T-1/2=33(2) s. In addition, two isomeric transitions in Cu-70 have been observed at energies of 101.1(3) and 141.3(3) keV, and it allowed the relative placement of the three Cu-70 isomeric states and their tentative spin and parity assignments. The new Cu-70 isomer was found to be weakly populated in the beta decay of Ni-70. It allowed the construction of the Ni-70 decay scheme. Furthermore, the beta decay of the three Cu-70 isomers to Zn-70 has been measured and their decay schemes are presented. The Ni-70 beta decay to the isomeric states in Cu-70 and their subsequent isomeric decay and beta decay to Zn-70 are discussed within the extreme shell-model picture of two valence nucleons outside the semidouble magic Ni-68(28)40 core and it yields satisfactory results. Large-basis shell-model calculations using Ni-56(28)28 as the core and a realistic effective interaction support rather well the suggested interpretation.