rprocessus

Rprocessus is a term that appears infrequently in scholarly writing and does not have a single, established definition in major reference works. In many cases, it is encountered as an alternate spelling or shorthand for the rapid neutron capture process, commonly abbreviated as the r-process, a key mechanism of nucleosynthesis in the universe.

In the r-process, nuclei rapidly accumulate neutrons in environments with extremely high neutron flux. The rate of neutron captures exceeds the rate of beta decay, pushing nuclear species far from the valley of stability. When the neutron flux subsides, these neutron-rich nuclei beta-decay toward stability, forming many of the heavy elements beyond iron, including precious metals and actinides.

Astrophysical sites proposed for the r-process include core-collapse supernovae and neutron star mergers. In recent years, observations of kilonovae accompanying gravitational wave events, such as GW170817, provided compelling evidence that neutron star mergers produce substantial quantities of r-process nuclei. The patterns of elemental abundances observed in old stars also support a significant r-process contribution to galactic chemical evolution. However, the exact sites and the detailed physical conditions (neutron density, temperature, and timescale) remain active areas of research. Researchers discuss several variants, including main and weak r-processes, to explain different features in the observed abundance distribution.

Notes: The term rprocessus is not widely standardized; when encountered, it is often a stylistic variant or a reference to the same r-process concept in a Latinized or foreign-language context. For most purposes, the established term r-process is preferred.