Can black hole accretion produce Li-7?

An investigation has been made of spallation nuclear processes in an ion pressure-supported accretion torus around a black hole. It has been found that, within the torus, Be-9, B-10, and B-11 are produced in cosmic abundance ratios relative to Li-7, while D and He-3 production is relatively small, and Li-6 production is high by a factor of 3. However, Li-6 nuclei produced in the torus are preferentially destroyed in cooler regions, hence outflow from the torus may effectively serve to enrich the universe with Li-7. It is shown that the ion torus that may exist around a black hole at the Galactic center, or the hypothetical black holes which constitute the Galactic dark matter, could have been the site of Li-7 production. In case of the dark matter black holes, for plausible accretion disk viscosities, this mechanism requires massive black holes of M greater than 500 solar masses. 43 refs