Slide 8 of 31
Notes:
The overabundance of light elements in the Universe is due to the fragmentation of the medium and heavy nuclei, the remains of which are almost always Li, Be and B.
This fragmentation is called spallation.
A quantitative analysis of the effects of spallation on the abundance of cosmic rays is difficult however. We would need to know what all the collision cross-sections for the various processes involved are - it’s further complicated because the relative abundances (which we will take a look at later) seem to change with energy.
