  Using a Monte Carlo code which incorporates the delayed mixing into the ISM
of supernovae nucleosynthetic yields and ejecta kinetic energies (including
events with very large energies, e.g. collapsars/hypernovae), we tested three
evolutionary models of spallogenic light element origin, specifically Be. The
CRI, in which the cosmic rays are accelerated out of an ISM which is
increasingly metal poor at early times, under-predicts the measured Be
abundance at the lowest [Fe/H], the increase in [O/Fe] with decreasing [Fe/H]
indicated by recent data notwithstanding. The CRS, in which cosmic rays with
composition similar to that of the current epoch cosmic rays are accelerated
out of fresh supernova ejecta and maintain a constant metallicity at all
epochs, can account for the measured Be abundances with an acceleration
efficiency that is in good agreement with the current epoch cosmic-ray data.
The LECR, in which a postulated low energy component also accelerated out of
fresh ejecta coexists with the CRI cosmic rays, can account for the
observations as well, except that the required acceleration efficiency becomes
prohibitively large for some of the parameters that have been previously
assumed for this as-yet undetected cosmic-ray component.
