Does Cosmic Ray Spallation Produce Boron?

Cosmic ray spallation is thought to be responsible for the abundance in the universe of some light elements—lithium, beryllium, and boron—as well as the isotope helium-3. ... Boron can also be created directly. The beryllium and boron are brought down to the ground by rain.

Where does most of the boron and beryllium in the universe come from?

These two elements, not coincidentally, are also bound together in their origins, for all beryllium and most boron are produced deep in space by cosmic rays. Only lithium and deuterium, an isotope of hydrogen, share this origin.

What does cosmic rays consist of?

Cosmic rays originate as primary cosmic rays, which are those originally produced in various astrophysical processes. Primary cosmic rays are composed mainly of protons and alpha particles (99%), with a small amount of heavier nuclei (≈1%) and an extremely minute proportion of positrons and antiprotons.