A low cost optical radiocarbon (14C) sensor for greenhouse gas source attribution

Abstract:

Radiocarbon (¹⁴C) provides a convenient means for the attribution of atmospheric greenhouse gases between anthropogenic and biogenic sources. Unfortunately, routine measurements are costly and require extensive sample preparation to meet sensitivity goals only achievable at large accelerator mass spectrometer facilities. We describe an alternate approach in which a laser is used to selectively record the absorption signatures of the ¹⁴C isotope of CO₂. The designed instrument will allow for bench-top measurements of ¹⁴CO₂ at and below ambient levels (~1.2 parts-per-trillion). The use of a commercially available mid-infrared quantum cascade laser as the optical source greatly reduces the cost of the instrument over more complicated sources and should allow for routine inline measurements.