Ground-state band and deformation of the Z=102 isotope 254No

The ground-state band of the Z=102 isotope 254No has been identified up to spin 14, indicating that the nucleus is deformed. The deduced quadrupole deformation, β=0.27, 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 254No up to spin 14 means that its fission barrier persists at least up to that spin

Structure of the Odd-A, Shell-stabilized nucleus No102253

In-beam γ-ray spectroscopic measurements have been made on No102253. A single rotational band was identified up to a probable spin of 39/2, which is assigned to the 7/2+[624] Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interprete the sparse data set associated with cross sections of around 50nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the γγ matrix

Orientation dependence in molecular dynamics simulations of shocked single crystals

The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb$48Ca,2n$ reaction at 215 and 219 MeV. This nucleus is populated up to spin 22h and excitation energy >˜6 MeV above the yrast line, with the half-maximum points of the energy distributions at ˜5 MeV for spins between 12h and 22h. This suggests that the fission barrier is >˜5 MeV and that the shell-correction energy persists to high spin