Magnetic dipole moments of Cu 58 and Cu 59 by in-source laser spectroscopy

Online measurements of the magnetic dipole moments and isotope shifts of $^{58}\mathrm{Cu}$ and $^{59}\mathrm{Cu}$ by the in-source laser spectroscopy method are reported. The results for the magnetic moments are $\ensuremath{\mu}$ ($^{58}\mathrm{Cu}$) $=+0.52(8) {\ensuremath{\mu}}_{N},\ensuremath{\mu}$($^{59}\mathrm{Cu}$) $=+1.84(3) {\ensuremath{\mu}}_{N}$ and for the isotope shifts $\ensuremath{\delta}{\ensuremath{\nu}}^{59,65}=1.72(22)$ GHz and $\ensuremath{\delta}{\ensuremath{\nu}}^{58,65}=1.99(30)$ GHz in the transition from the $3{d}^{10}4s $$^{2}\mathrm{S}$${}_{1/2}$ ground state to the $3{d}^{10}4p $$^{2}\mathrm{P}$${}_{1/2}$ state in Cu I. The magnetic moment of $^{58}\mathrm{Cu}$ is discussed in the context of the strength of the subshell closure at $^{56}\mathrm{Ni}$, additivity rules and large-scale shell model calculations.