ACCELERATOR MASS SPECTROMETRY (AMS) DATING

A radiocarbon dating technique where a nuclear accelerator is used to enable the individual counting of 14C atoms. Conventional mass spectrometers are able to separate the three isotopes of carbon, 12 C, 13 C and 14 C, by virtue of their mass difference, but are not sensitive enough to detect natural concentrations of 14 C. The 14 C ion beam is also affected by the presence of ions of the same mass such as 14 N and 13 CH. A nuclear accelerator is required to enable the discrimination between the contaminating ions and to provide the 14 C ions with sufficient energy to enable their detection. The equipment required is expensive, but the sample throughput rate is greater than conventional techniques. The big advantage of ams dating over conventional radiocarbon dating is the sample size requirement of ~1 mg in contrast to the >2 g required by most conventional laboratories.