An overview of world-wide AMS facilities
Prof. Walter Kutschera1
1University of Vienna, Faculty of Physics, Isotope Physics, , Austria
The current review will attempt to cover the world-wide spread of AMS facilities, reflecting the tremendous success of AMS to explore our environment at large.
Accelerator Mass Spectrometry (AMS) started in earnest in 1977, when physicists at three nuclear physics laboratories in North America (Berkeley, McMaster, Rochester) realised almost simultaneously that accelerators can be used to measure extremely low abundances of long-lived radioisotopes by ‘counting atoms rather than decays‘.
After early AMS experiments with existing accelerators, including cyclotrons, linear accelerators and tandem accelerators, it was quickly realised that tandem accelerators are best suited for AMS of 14C and a few other radioisotopes. The chief reason is the complete absence of the interference from the isobar 14N, because nitrogen does not form stable negative ions. Therefore, with very few exception (e.g. the ATLAS linear accelerator at Argonne National Lab), tandem accelerators became the dominant accelerator type for AMS.
The field of AMS benefitted greatly from the early development of dedicated AMS facilities, pioneered by the late Ken Purser. Eventually the field developed from a handful AMS facilities in the early 1980s to a world-wide total of ~150 in 2021. Originally, AMS at existing tandem accelerators and dedicated AMS facilities manufactured by High Voltage Engineering Europe (HVE) and by National Electrostatics Corporation (NEC) dominated the field. Later, intense ion-beam studies of the AMS group at the ETH Zuerich, partly in collaboration with NEC, allowed a considerable reduction of the terminal voltage from 3 MV to eventually 0.2 MV. This resulted in a laboratory-size AMS facility called MICADAS (Mini Carbon Dating System), which is now being manufactured by the spin-off company Ionplus.
Although 14C is by far the most-used radioisotope in research with AMS, many other radioisotopes in the half-life range from a few years to 100 million years (~40) are of interest for AMS studies in a multitude of different fields, examplified by the versatile program of the AMS-15 Conference. A number of these radioisotopes (e.g. 10Be, 26Al, 36Cl, 41Ca, 129I, and some of the actinide isotopes) can nowadays almost be considered ‘routine‘ ones, but there are quite a few rarely used radioisotopes which require special techniques to reduce the interference from stable isobars. The VERA lab has successfully developed the Ion Laser InterAction Spectrometry (ILIAMS) system to allow for yet difficult-to-measure radioisotopes like 90Sr, 135Cs, and 182Hf (Martschini et al., this meeting). ILIAMS also opens up new possibilities for low-energy accelerators to measure 36Cl by complete suppression of 36S.
One purpose of the current review is to present a complete list of all AMS facilities around the world, to the best of the author’s knowledge. For this I am thankful for the information provided by Henri van Oosterhout (HVE), Mark Sundquist (NEC), and Hans-Arno Synal (ETHZ). Comments and corrections for the list of AMS facilities are welcome and will be considered in the paper for the proceedings of the conference.
Born 1939 in Vienna. Ph.D. University of Graz 1965. 27 years away from Austria working in basic and applied nuclear physics research at various Institutions in Heidelberg, Munich, Tokyo, Chicago, Jerusalem, mainly in connection with tandem accelerators. From 1993 on Professor of Physics at the University of Vienna. Build-up of the Vienna Environmental Research Accelerator (VERA), an AMS facility for ‘all’ isotopes. His research covers many sections of AMS. Since 2008 Emeritus Professor of Physics at the University of Vienna. 2010 recipient of the Erwin Schrödinger Prize of the Austrian Academy of Sciences for his life-work in AMS.