Nuclear levels in 60Ni from the decay of 60Cu

Abstract

Radiations from 60Cu have been investigated by means of a single channel NaI-scintillation spectrometer and a magnetic lens type β-ray spectrometer. Moreover, γ — γ coincidences using two single channel scintillation spectrometers have been measured. Three positon groups and eight γ-rays were found (see {xgtable I and III}). A decay scheme is proposed in which probable spin and parity assignments are given to four new levels in 60Ni at 2.18 ± 0.02; 3.11 ± 0.03; 3.52 ± 0.05 and 3.98 ± 0.04 MeV. From the decay characteristics a spin 2+ could be assigned unambiguously to the 60Cu ground state. The total mass-difference of 6.23 ± 0.02 MeV between 60Cu and 60Ni fits well into a linear plot of mass-differences of Cu-Ni and Cu-Zn isobars as a function of the mass number A. A discussion of some extrapolations from those plots to yet uncertain decay characteristics of nuclides in this region is added. A description of the components of the scintillation spectrometer and the two-fold coincidence circuit is given.