Düsseldorf 2007 – wissenschaftliches Programm
MS 3.2: Vortrag
Dienstag, 20. März 2007, 14:30–14:45, 5F
The new French 5 MV AMS facility: ASTERisques — •Didier Bourlès, Maurice Arnold, Georges Aumaître, Régis Braucher, Fredéric Chauvet, and Silke Merchel — CEREGE, CNRS-IRD-Université Aix-Marseille, F-13454 Aix-en-Provence, France
A new 5 MV accelerator mass spectrometry (AMS) system, developed by HVE, has been installed at CEREGE.
Ions are extracted from a hybrid ion source which can handle gaseous and solid samples. On the low-energy side the ions are separated by an energy-analyser, a 54° electrostatic deflector, and a mass-analyzer, a 90° magnet, equipped with a fast-bouncing system. The tandetron accelerator  contains a gas stripper and active stripper gas regulation. On the high-energy side, a 90° analysing magnet is followed by Faraday cups for stable isotope measurements. The rare isotopes are detected by a 4-anode gas ionization chamber after passing through an absorber foil, a 35° electrostatic deflector and a 30° vertical analysing magnet for further background reduction.
The system is fully dedicated to applied research. We will mainly measure long-lived (half-life > 100000 a) cosmogenic radionuclides isolated from geological and environmental samples. The determination of e.g. Be-10, Al-26, Cl-36 in bed rock, sediments and ice cores will help to reconstruct climatic changes, seismic activities, volcano eruptions and rock falls in the past . Understanding past events will enable us to better predict such events in the future.
 A. Gottdang et al., NIMB 190 (2002) 177.  J.C. Gosse and F.M. Phillips, Quat. Sci. Rev. 20 (2001) 1475.