The AMS technique allows to date samples containing only a few mg of carbon.
When cosmic rays enter the atmosphere, they undergo various transformations, including the production of neutrons.
The resulting neutrons participate in the following reaction: n + 14N is relatively common, as nitrogen constitutes nearly 80% of Earth's atmosphere.
is a radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to ca. Within archaeology it is considered an absolute dating technique.
The technique was discovered by Willard Frank Libby and his colleagues in 1949.