Combined decay and laser spectroscopy measurements of the isotope ${}^{214}\mathrm{Fr}$ are reported, using the collinear resonance ionization spectroscopy (CRIS) technique at the ISOLDE facility at CERN. For the $I^{\pi }=(1^{-})$ spin assignment, the $g$-factor value of $g({}^{214}\mathrm{Fr})=+0.241(16)$ corresponds to a relatively pure $(\pi 1h_{9/2}$ $\otimes$ $\nu 2g_{9/2})$ ground-state configuration. An alternative interpretation with $g({}^{214}\mathrm{Fr})=+0.144(10)$, for a $\left(2^{-}\right)$ spin assignment suggests a greater contribution of configuration mixing with the $\nu 1i_{11/2}$ orbital. As the $N=126$ shell closure is passed, a kink is observed at the $\delta {\langle r^2\rangle }^{213,214}$ value, which is analogous to the behavior observed in the neighboring isotopic chains.

• Received 10 August 2016
• Publisher error corrected 17 November 2016

DOI:https://doi.org/10.1103/PhysRevC.94.054305

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society