PRODUCTION OF LI, BE, AND B IN THE EARLY GALAXY

We consider the production of lithium, beryllium, and boron via collisions between cosmic rays and interstellar gas nuclei during the early (Population II) evolution of the Galaxy. There is a qualitative as well as quantitative difference from the usual (Population I) spallation production of these intermediate-mass nuclei. In particular, since Li-6 and Li-7 can be produced via alpha + alpha-fusion reactions whereas Be-9, B-10, and B-11 require CNO nuclei as spallation targets, the ratio of Li to Be or B is vastly different from that predicted in previous spallation calculations. Current data do not exclude (and may even support) the possibility that significant amounts of Li are produced through this mechanism and recently quoted constraints must be reconsidered in light of our results.