THE ROLE OF GRAVITATIONAL SUPERNOVAE IN THE GALACTIC EVOLUTION OF THELI, BE AND B-ISOTOPES

The observed Be and B relationships with metallicity clearly support t he idea that both elements have a primary origin and that they are pro duced by the same class of objects. Spallation by particles accelerate d during gravitational supernova events (SNII, SNIb/c) seems to be a l ikely origin. We show, in the context of a model of chemical evolution , that it is possible to solve the Li, Be and B abundance puzzle with the yields recently proposed by Ramaty et al., provided that SNII are unable to accelerate helium nuclei significantly and that different me chanisms are allowed to act simultaneously.