Abstract
Beta-decay half-lives and β-delayed neutron-emission probabilities of the very neutron-rich nuclei and have been measured. These isotopes, which lie at or close to the N=28 magic shell, were produced in interactions of a 60 MeV/u beam from GANIL (Grand Accélérateur National d’Ions Lourds) with a target, and were separated by the doubly achromatic spectrometer LISE (Ligne d’Ions Super Epluchés). Their decay was studied by a β-n time correlation measurement. The results are compared to recent model predictions and indicate a rapid weakening of the N=28 shell effect below . The nuclear structure effects reflected in the decay properties of the exotic S and Cl isotopes may be the clue for the astrophysical understanding of the unusual Ca abundance ratio measured in the solar system as well as the Ca-Ti-Cr anomalies observed in E. King inclusions of the Allende meteorite.
- Received 11 November 1992
DOI:https://doi.org/10.1103/PhysRevC.47.2941
©1993 American Physical Society