@article {longworth_radiocarbon_2022,
	title = {Radiocarbon measurement of CO2 from carbonate minerals using a hybrid gas ion source with an open split interface},
	journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	volume = {531},
	year = {2022},
	month = {11/2022},
	pages = {49{\textendash}55},
	abstract = {We have developed a method for measuring radiocarbon in carbonate minerals as CO2 gas via a NEC MCSNICS hybrid sputter gas ion source (HGIS). The method uses helium as a carrier gas to displace CO2 from sample vials to an open split, where a glass capillary samples the mixture for delivery directly to the HGIS. This method skips the gas transfer and quantification steps used in a closed inlet HGIS system, simplifying sample measurement. Samples larger than 8 mg carbonate can be measured. Results from measurements of consensus standards (TIRI I, IAEA C2, and an internal modern shell standard), and samples from a marine core (F14C = 0.4{\textendash}1.15) show that the method agrees well with traditional AMS measurement of the same samples as graphite, and that the 1σ uncertainty is about 1\%. We discuss advantages and disadvantages of continuous flow sample introduction, and the effect of reduced precision on calibrated age-depth models produced using gas-source data.},
	keywords = {Carbonate, Hybrid gas ion source, radiocarbon},
	issn = {0168-583X},
	doi = {10.1016/j.nimb.2022.08.013},
	url = {https://www.sciencedirect.com/science/article/pii/S0168583X2200218X},
	author = {Longworth, Brett E. and Burton, Joshua R. and Pendleton, Simon L. and Moser, Sydney D. and Roberts, Mark L. and Kurz, Mark D.}
}
