Fr.: processus s
A → nucleosynthesis process by which → chemical elements heavier than → copper are formed through a slow flux of → neutrons absorbed by atomic nuclei (→ neutron-capture element). The → capture of neutrons occurs on time scales that are long enough to enable unstable nuclei to decay via the emission of a → beta particle before absorbing another neutron. Prominent s-process elements include → barium, → zirconium, and → yttrium. See also: → r-process.