PROGRESS AT THE GRONINGEN AMS FACILITY

A new generation accelerator mass spectrometer (AMS) is operational since May 1994 at the Centre for Isotope Research in Groningen, The Netherlands. The fully automated and high throughput AMS system, manufactured by High Voltage Engineering Europa (HVEE) is dedicated to radiocarbon analysis. The model 4130 C-14 AMS is able to analyse up to 3000 samples per year. The system is characterized by a simultaneous transport of all three isotopes. Since the system is fully operational, various tests have been done to obtain insight in the system performance. Background, including sample preparation is, at present, approximately 45 ka and is still improving, whereas machine background is negligible. Performance tests on identical samples and cross checking with conventional C-14 decay counting and C-13 spectrometry showed a precision on the (13)delta and the C-14/C-12 ratio of better than 2 parts per thousand and 0.5 pMC respectively.