The length of time it takes for the light to decay from its initial intensity is used to calculate the concentration of radiocarbon in the gas mixture in the cavity.
The highly reflective mirrors create an effective path longer than 5 kilometers for interactions between the light and the gas sample.
"In principle, we can use our apparatus to detect many other molecules such as methane, nitrous oxide and other greenhouse gases or chemicals of interest for national security or forensics." How it works The SCAR device detects radiocarbon levels by measuring how laser light interacts with the carbon dioxide that is produced when a given sample is burned.
For analysis, the carbon dioxide from a burnt sample is placed into the instrument's vacuum measurement chamber.
AMS is faster and needs a much smaller sample, but is more expensive.
"With a portable instrument, direct measurements could be conducted on-site, with results returned in a very short time," Galli said.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.So the most important things about AMS radiocarbon dating as opposed to conventional is that the sample size is much, much smaller.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.