A mean lifetime measurement using the Doppler shift attenuation method has been performed at GASP in order to measure the quadrupole moment of the yrast superdeformed band of ${}^{144}\mathrm{Gd}$. The extracted intrinsic quadrupole moment above the backbending, $Q_0{=13.7\mathrm{}}_{-0.9}^{+1.1\mathrm{}}\hspace{0.5em}e$ b, is in nice agreement with cranked shell model predictions. To fit the data properly below the backbending a smaller $Q_0$ value is required ${(11.6\mathrm{}}_{-1.0}^{+1.4\mathrm{}})e$ b. This is consistent with the predicted lower deformation in the second well for the configuration without high-$N$ $(\pi N=6\mathrm{}$ and $\nu N=7)$ intruder orbitals occupied.

• Received 3 June 1999

DOI:https://doi.org/10.1103/PhysRevC.60.054302