r-process

(redirected from R process)

r-process

A rapid process of nucleosynthesis that is thought to occur when there is a very high flux of neutrons, as in certain supernova explosions. All nuclei with a mass number greater than bismuth–209 (see s-process) and all neutron-rich isotopes heavier than iron have been produced by the r-process. The process involves the capture by a nucleus of two or more neutrons in quick succession. The nucleus will then undergo chains of beta decay, this beta-particle (electron) emission having been suppressed during the rapid capture process. The decay product will be a stable neutron-rich nucleus. Many heavy nuclei can be produced both by the r- and the s-process.

r-process

[′är ‚prä·səs]
(nuclear physics)
The synthesis of elements and nuclides in supernovas through rapid captures of neutrons in a matter of seconds, followed by beta decay.