PROGRESS AT THE GRONINGEN AMS FACILITY

A new generation accelerator mass spectrometer (AMS) is operational si nce May 1994 at the Centre for Isotope Research in Groningen, The Neth erlands. The fully automated and high throughput AMS system, manufactu red by High Voltage Engineering Europa (HVEE) is dedicated to radiocar bon analysis. The model 4130 C-14 AMS is able to analyse up to 3000 sa mples per year. The system is characterized by a simultaneous transpor t of all three isotopes. Since the system is fully operational, variou s tests have been done to obtain insight in the system performance. Ba ckground, including sample preparation is, at present, approximately 4 5 ka and is still improving, whereas machine background is negligible. Performance tests on identical samples and cross checking with conven tional 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 thou sand and 0.5 pMC respectively.