New atomic-mass determinations are reported which establish the masses of Hf174 and W180 with significantly improved precision, and lead to new values for the double-neutron separation energies S2n of Hf176, W180, and W182. A plot of S2n in the region 94<~N<~114 now shows systematic downward breaks at N=98, 104, and 108. These features are interpreted in terms of energy gaps above the Nilsson single-particle levels 92+ (N=108), 52- (N=98), and 1/2- (N=104).
ASJC Scopus subject areas
- Physics and Astronomy(all)