Noun
s-process (plural s-processes)
(nuclear physics, astrophysics) the relatively slow nucleosynthesis process, in giant stars, in which neutron capture synthesizes elements up to atomic mass number 210 (at which point alpha decay becomes a deterrent to further building).
Apart from the s-process, the latter three isotopes have been synthesized as a result of the r-process (lead-204 is not produced in this manner because its isobar mercury-204 is stable, and it is not formed as a decay product of r-process products). Source: Internet
In the s-process, a nucleus in a star captures another slow neutron, and if the resulting nucleus is unstable, it typically undergoes a beta decay to become an element of the next atomic number. Source: Internet
Observation of barium abundances some 20-50 times greater than found in unevolved stars is evidence of the operation of the s-process within such stars. Source: Internet