Instruments used in radiocarbon dating
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.
For analysis, the carbon dioxide from a burnt sample is placed into the instrument's vacuum measurement chamber.
Even if the absorption is small for a single pass, thousands of passes provide enough absorption to detect even trace amounts of radiocarbon.
"Although the instrument is relatively simple, the performance obtained by our system is a result of many years of studying of the physics of the various optical components," Giusfredi said.
"Accelerator mass spectroscopy can be used to carbon date bones, wood, fabrics or anything of biological origin, pinpointing its age of up to 50,000 years ago," said Iacopo Galli, a member of the research team.
"Using our new technique, we can do something similar but with a lower cost and with a faster delivery time for the results." The researchers report that their SCAR instrument can detect radiocarbon dioxide concentration with a precision of 0.4 percent, which approaches the 0.2 percent precision of the best accelerator mass spectrometers.