Neutron capture

<p>Neutron capture is a <a href="/facts/Nuclear_reaction/202yClUr">nuclear reaction</a> in which an <a href="/facts/Atomic_nucleus/orpIm5Xl">atomic nucleus</a> and one or more <a href="/facts/Neutron/oRCM1geb">neutrons</a> collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged <a href="/facts/Proton/clCjepXP">protons</a>, which are repelled <a href="/facts/Electrostatics/bxkuW6s4">electrostatically</a>.
</p><p>Neutron capture plays a significant role in the cosmic <a href="/facts/Nucleosynthesis/F9MIeADF">nucleosynthesis</a> of heavy elements. In stars it can proceed in two ways: as a rapid process (<a href="/facts/R-process/wEDL01yc">r-process</a>) or a slow process (<a href="/facts/S-process/31HVkqkI">s-process</a>). Nuclei of <a href="/facts/Mass_number/VyBbJ1oI">masses</a> greater than 56 <a href="/facts/Iron_peak/GYAe3weY">cannot be formed</a> by exothermic <a href="/facts/Thermonuclear_reaction/hP0gLDqj">thermonuclear reactions</a> (i.e., by <a href="/facts/Nuclear_fusion/hP0gLDqj">nuclear fusion</a>) but can be formed by neutron capture.
Neutron capture on protons yields a line at 2.223 MeV predicted and commonly observed in <a href="/facts/Solar_flares/6kCvPKxD">solar flares</a>.
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Neutron capture open-in-new

Neutron capture