Abstract
The proton-rich isotopes , and were produced in bombardments of , and , respectively, and their -decay properties were investigated with the use of a fragment mass analyzer and a double-sided Si strip detector. These data yielded unambiguous identifications of and and half-lives for all three Pb nuclei that are more precise than previously available values. An examination of reduced widths in the Pb mass region leads to the conclusion that the shell gap is greatly reduced for neutron numbers midway between 82 and 126. Available mass data, manifested in values and two-proton separation energies of even-even nuclei with the same neutron numbers, support this conclusion.
- Received 15 April 1999
DOI:https://doi.org/10.1103/PhysRevC.60.011302
©1999 American Physical Society