<i>g</i>factor measurements of s isomeric states in neutron-rich nuclei around⁶⁸Ni produced in projectile-fragmentation reactions

Abstract

We report the first g factor measurement on microsecond isomers of neutron-rich nuclei produced in projectile-fragmentation reactions at intermediate energies. The nuclides in the vicinity of 68Ni were produced and spin oriented following the fragmentation of a 76Ge, 61.4 MeV u−1 beam at GANIL. The LISE spectrometer was used to select the nuclei of interest. The time-dependent perturbed angular distribution (TDPAD) method was applied in combination with the heavy-ion–gamma correlation technique to measure the g factors of 69mCu (Jπ = 13/2+, T1/2 = 350 ns) and 67mNi (Jπ = 9/2+, T1/2 = 13.3 μs). Specific details of the experimental technique and the comparison of the results (|g(69mCu)| = 0.225(25) and |g(67mNi)| = 0.125(6)) with theoretical calculations are discussed. These results provide another indication of the importance of proton excitations across the Z = 28 shell gap.