The creation of free neutrons by electron capture during the rapid compression of the supernova core along with assembly of some neutron-rich seed nuclei makes the r process a primary process ; namely, one that can occur even in a star of pure H and He, in contrast to the B2FH designation as a secondary process.

The creation of free neutrons by electron capture during the rapid collapse to high density of the supernova core along with assembly of some neutron-rich seed nuclei makes the r process a primary process ; namely, one that can occur even in a star of pure H and He, in contrast to the B2FH designation as a secondary process building on preexisting iron.

0.041 seconds.