r-process - Wikipedia
In nuclear astrophysics, the rapid neutron-capture process, also known as the r-process, is a set of nuclear reactions that is responsible for the creation of approximately half of the atomic nuclei heavier than iron, the "heavy elements", with the other half produced by the p-process and s …
Origin of the heaviest elements: The rapid neutron-capture process
2021年2月1日 · The rapid neutron-capture process plays a major role in the production of heavy elements from Fe to U. This review surveys the history and current understanding of $r$-process nucleosynthesis, covering new data from atomic and nuclear physics, astrophysical modeling of $r$-process sites, astronomical observations of stellar abundances, and ...
R-process | chemistry | Britannica
neutron capture, type of nuclear reaction in which a target nucleus absorbs a neutron (uncharged particle), then emits a discrete quantity of electromagnetic energy (gamma-ray photon). The target nucleus and the product nucleus are isotopes, or forms of the same element. Thus phosphorus-31, on undergoing neutron capture, becomes phosphorus-32.
Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
2019年1月5日 · Abstract: The production of about half of the heavy elements found in nature is assigned to a specific astrophysical nucleosynthesis process: the rapid neutron capture process (r-process). Although this idea has been postulated more than six decades ago, the full understanding faces two types of uncertainties/open questions: (a) The ...
2021年2月1日 · neutrons are the slow (s)-process and the rapid (r)-process (due to low or high densities of neutrons avail-able and the resulting reaction timescales of neutron cap-tures). In the s-process, taking place during stellar evo-lution and passing through nuclei near stability, there is su cient time for beta-decay between two neutron cap-tures.
Nucleosynthesis and observation of the heaviest elements
2023年2月15日 · The rapid neutron capture or ‘r process’ of nucleosynthesis is believed to be responsible for the production of approximately half the natural abundance of heavy elements found on the periodic table above iron (with proton number \(Z=26\)) and all of the heavy elements above bismuth (\(Z=83\)).
r-Process nucleosynthesis in gravitational-wave and other …
2022年4月4日 · These include insights into rapid neutron-capture (r-process) nucleosynthesis in neutron-star mergers and other astrophysical sites, such as collapsars and magnetorotational supernovae, with...
Slow capture produces nuclei near the valley of beta stability, while rapid capture (i.e., rapid compared to typical beta-decay timescales) ini-tially produces very neutron-rich radioactive nuclei that eventually beta-decay towards the valley of beta stability. Some nuclei can be built by more than one process, as illustrated in Fig. 1.
Radiative neutron capture reaction rates for nucleosynthesis: The ...
2023年6月2日 · The nucleosynthesis via rapid neutron capture process (r-process) occurring in astrophysical environment is regarded as carrying the load of producing nearly half of the heavy elements present in nature. This broad-spectrum problem poses a great challenge for physics.
Production mechanisms for elements heavier than iron, by slow (s-process) and fast (r-process) captures of neutrons, have been known for a long time , yet finding conditions in Nature and understanding the physics that allow these processes to robustly operate has been more elusive. Half of the elements heavier than iron are made by the s-process.