The chemical history of $^{14}{\rm C}$ in deep oilfields

Abstract

14C is an overwhelming background in low-background underground experiments, to the point where the observation of the all-important (pp) neutrinos from the Sun can not be observed in carbon-containing experiments. This paper shows that 14C purity can be improved by four orders of magnitude by a careful selection of the gas field. Two large reduction factors are at work: the low chemical affinity of methane to single carbon, and the migration of natural gas away from nitrogen-bearing kerogen during as the oilfield matures.