"AMS (Accelerator Mass Spectrometry) Radiocarbon Dating"

Definition: AMS (Accelerator Mass Spectrometry) radiocarbon dating is a way to obtain radiocarbon dates from samples that are far tinier than that needed for standard radiocarbon dating. Standard c14 dates require amounts of between 1 and 10 grams of charcoal; AMS can use as little as 1-2 milligrams, and under special circumstances to samples as small as 50-100 micrograms.

In standard radiocarbon dating, scientists perform a limited or proportional count of the decaying C14 atoms. In AMS dating, researchers use an accelerator-based mass spectrometer to count all the C14 atoms, rather than just those atoms which are decaying. AMS dates are therefore more precise and require smaller samples.

Sources

For more detailed information on this and other dating techniques used in archaeology, see the Dating in Archaeology Short Course.