Li, Be, and B production in proton-induced reactions: implications for astrophysics and space radiation effects

Cross sections for the production of mass 6 to 11 isobars from proton spallation of carbon targets have been measured at bombarding energies of 45, 55, 60, 65, 75 and 100 MeV. The results of these measurements and similar studies by other groups are used to test theories of Li, Be and B nucleosynthesis. The measured abundance ratios for 7Li/6Li, 11B/10B, Li/Be and B/Li can be reproduced using measured cross sections and models which propose interstellar proton fluxes phi(E) of the form (m/sub p/c2 + E)-2.6, E/sup -γ/ (γ approximately equal to 1.5--2.0) or E-3 for E greater than 30 MeV, if a substantial amount of 7Li is synthesized via some other source. The cross sections for formation of Li, Be and B are also of importance because of possible high LET effects in biological material exposed to cosmic radiation. Our measurements are compared with calculated cross sections that have been used to estimate LET effects. 3 tables, 4 figures