Electric Quadrupole Moment of theRn211632−Isomer: Absence of Core Deformation at Very High Spins

The electric quadrupole moments of ${}_{}{}^{211}{}_{}{}^{}\mathrm{Rn}$ isomers were determined as $Q\left({\frac{17}{2}}^{-}\right)=19\mathrm{}\left(2\right)\mathrm{}$ e.fm2 and $Q\left({\frac{63}{2}}^{-}\right)=160\mathrm{}\left(22\right)\mathrm{}$ e.${\mathrm{fm}}^2$ via measurements of the quadrupole interaction in a Bi single-crystal host. The results indicate that the spherical shape is preserved in the lead region even at the core-excited very-high-spin regime, in contradiction to theoretical predictions.