COSMIC-RAY NUCLEOSYNTHESIS IN THE EARLY GALAXY

Cosmic ray spallation/fusion reactions may yield astrophysically inter esting amounts of lithium, beryllium and boron during the early evolut ion of the Galaxy. In particular, since alpha,alpha fusion reactions c an produce Li-6 and Li-7 whereas Be and B require CNO nuclei as spalla tion targets, the Pop II ratios of Li to Be and/or B are vastly differ ent from their Pop I counterparts. Current data on Pop II Be do not ex clude the possibility that significant amounts of lithium have been pr oduced via this mechanism. The observed increase in the Pop II abundan ce of beryllium with increasing metallicity points to synthesis during the early Galaxy. The boron to beryllium ratio is relatively insensit ive to model-dependent, evolutionary uncertainties and could provide a signature for cosmic ray nucleosynthesis during the early Galaxy.