DR CHRISTINE PRIOR In conventional radiocarbon dating, you’re measuring the presence of the C-14 when you measure the radioactive decay.
The C-14 decays with the beta particle, and you have some detection equipment and you count the C-14s one by one.
A mass spectrometer is an instrument that uses a series of magnets to bend a beam of ions and then physically count how many there are, so with AMS radiocarbon dating, we can measure a carbon-12, 13 and 14 beam, and we measure the ratio of 14 to 13, and from that, we can tell how much C-14 is in the sample.
What you’re doing is measuring all of the carbon isotopes in the sample – the 12, 13 and 14 – the accelerator operates like a giant mass spectrometer.Dr Christine Prior is Team Leader of the Rafter Radiocarbon Laboratory at GNS Science.In this video, she compares conventional and accelerator mass spectrometry (AMS) radiocarbon dating. Accelerator mass spectrometry (AMS) is a technique for direct measurement of the concentration of radioisotopes.A radiocarbon measurement can be obtained on a sample of ~0.5 mg of carbon, and measured to 40 years in uncalibrated radiocarbon age in a measurement time of 3040 minutes on each sample.