Laser Spectroscopy for Monitoring of Radiocarbon in Atmospheric Samples

In-situ monitoring of radiocarbon emissions is challenging due to the lack of a suitable method for sensitive online detection of this isotope. Here we report on a complete system for automatized continuous on-site monitoring of radiocarbon gaseous emissions from nuclear facilities. By combining radiocarbon detection using mid-infrared cavity ring-down spectroscopy and an advanced sampling system, an elevated amount of radiocarbon in an atmospheric-like gas matrix was detected. Radiocarbon was detected in the form of ¹⁴CO₂ after extraction of the carbon dioxide from the air sample. The system is also able to discriminate between radiocarbon in organic or inorganic molecular form by converting ¹⁴CH₄ into ¹⁴CO₂. This work lays the groundwork for further use of this technology in nuclear facilities for online on-site monitoring of radioactive gaseous emissions as well as future work on in-situ monitoring of atmospheric radiocarbon.