Ground-State Band and Deformation of theZ=102IsotopeN254o

The ground-state band of the $Z=102\mathrm{}$ isotope ${}^{254}\mathrm{No}$ has been identified up to spin 14, indicating that the nucleus is deformed. The deduced quadrupole deformation, $\beta =0.27\mathrm{}$, is in agreement with theoretical predictions. These observations confirm that the shell-correction energy responsible for the stability of transfermium nuclei is partly derived from deformation. The survival of ${}^{254}\mathrm{No}$ up to spin 14 means that its fission barrier persists at least up to that spin.