In-target resonance ionization was applied for the first time, to our knowledge, for isotope-shift and hyperfine splitting measurements at the Investigation of Radioactive Isotopes on Synchrocyclotron (IRIS) facility. The production yield of the short-lived Gd atoms and the selectivity of the laser ionization appear to be nearly two and seven times higher, respectively, compared with those of a conventional target–laser-ion-source system. Changes in mean-square charge radii $\delta \langle r^2\rangle {}_{A,A^{\text{'}}}$ for ${}^{145}\mathrm{Gd}$,${}^{145}\mathrm{Gd}{}^m$, and ${}^{143}\mathrm{Gd}{}^m$ and magnetic moments for ${}^{145}\mathrm{Gd}$ and ${}^{143}\mathrm{Gd}{}^m$ are determined. The stabilization influence of the proton subshell closure on the $\delta \langle r^2\rangle {}_{A,A^{\text{'}}}$ (i.e., on the deformation) behavior at $N<82$ was not observed.

• Received 22 February 2005

DOI:https://doi.org/10.1103/PhysRevC.72.017301