Definition of r-process in English:

r-process

noun

Astronomy
  • A nucleosynthetic process believed to occur in stars in circumstances of high neutron flux (e.g. in supernova explosions), in which atomic nuclei heavier than iron are formed from lighter ones by a succession of rapid neutron captures and slower beta decays.

Origin

1950s; earliest use found in Fred Hoyle (1915–2001), astronomer. From the initial letter of rapid + process.