Production of A=6,7 nuclides in the alpha+alpha reaction and cosmic ray nucleosynthesis - art. no. 065805

Cross sections for production of He-6, Li-6, Li-7, and Be-7 in the alpha alpha reaction were measured at bombarding energies of 159.3, 279.6, and 61 9.8 MeV and are found to decrease rapidly with increasing energy. These cro ss sections are essential for the calculation of the rate of nucleosynthesi s of the lithium isotopes in the cosmic rays and thereby play a key role in our understanding of the synthesis of Li, Be, and B. The results for Li-6 differ significantly from the tabulated values commonly used in cosmic ray production calculations and lead to lower production of Li-6.