Gas Ion Source Performance of the Environmicadas at Hekal Laboratory, Debrecen, Hungary

Abstract

A coupled accelerator mass spectrometer–gas interface system has been successfully operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary, since 2013. Over the last 6 years more than 500 gas targets were measured below 100 µg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2, and IAEA-C7 standards. The performance of our instrumentation shows good agreement with other published gas-interface system data and also shows a quite good agreement with the nominal value of international standard samples. There is a measurable but quite small memory effect after modern samples, but this does not significantly affect the final results. Typical ion currents at the low energy side were between 10–15 µA with a 5% CO2 in He mixing ratio. The relative errors average ±6% for samples greater than or equal to 10 µgC sample with mean count rates of 300 counts per microgram C for OxII. The blank is comparable with other systems, which is 0.0050 ± 0.0018 F14C or 34,000–47,000 yr BP, which allows for the routine measurement of both of small environmental and archeological samples.

A UNIVERSAL GAS INTERFACE FOR SIMULTANEOUS 14C AND δ13C MEASUREMENTS

“…Graphite measurements are precise but typically require sample sizes of 1 mg C, whereas gas measurements can be used for small samples down to a few μg C and require less preparation time, while providing a precision of around 0.5% (Ruff et al 2010). This is comparable to other MICADAS laboratories (Mollenhauer et al 2021;Molnár et al 2021), even if somewhat higher precisions of 0.2% can be achieved with higher sample sizes (Bard et al 2015).…”

A Note: Radiocarbon Data Comparison of Small Gaseous Samples Measured by Two Micadas at Eth Zurich and Ocean University of China

“…In particular, carbon cycle related investigations (e.g., compound-specific radiocarbon analysis) often require quick measurements of small-sized samples to get adequate information from samples with limited sizes. To provide quick 14 C measurements for smallsized CO 2 gaseous samples (Fahrni et al 2013;Haghipour et al 2019;Molnár et al 2021), the MIni CArbon DAting System (MICADAS) was developed at ETH Zurich (Synal et al 2007). MICADAS has now been commercialized and set up among research institutions (e.g., Schulze-König et al 2010;Bard et al 2015), in applications including carbon cycle studies (Eglinton et al 2021), paleoclimate reconstruction (Gottschalk et al 2018), archeological dating (Cersoy et al 2017) and biomedical research (Schulze-König et al 2010).…”