Laser and decay spectroscopy of the short-lived isotope Fr 214 in the vicinity of the N=126 shell closure

Abstract

Combined decay and laser spectroscopy measurements of the isotope Fr214 are reported, using the collinear resonance ionization spectroscopy (CRIS) technique at the ISOLDE facility at CERN. For the Iπ=(1-) spin assignment, the g-factor value of g(Fr214)=+0.241(16) corresponds to a relatively pure (π1h9/2 - ν2g9/2) ground-state configuration. An alternative interpretation with g(Fr214)=+0.144(10), for a (2-) spin assignment suggests a greater contribution of configuration mixing with the ν1i11/2 orbital. As the N=126 shell closure is passed, a kink is observed at the δ(r2)213,214 value, which is analogous to the behavior observed in the neighboring isotopic chains.