GAS ION SOURCE PERFORMANCE of the ENVIRONMICADAS at HEKAL LABORATORY, DEBRECEN, HUNGARY

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 g 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 A with a 5% CO2 in He mixing ratio. The relative errors average ±6% for samples greater than or equal to 10 gC 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.