Darmstadt 2008 – wissenschaftliches Programm
MS 3.3: Vortrag
Dienstag, 11. März 2008, 09:00–09:15, 3E
The French 5 MV AMS facility ASTERisques - Status after the first year — •Didier Bourlès1, Maurice Arnold1, Georges Aumaître1, Lucilla Benedetti1, Régis Braucher1, Frédéric Chauvet1, Robert C. Finkel1,2, and Silke Merchel1 — 1CEREGE, CNRS-IRD-Université Aix-Marseille, F-13454 Aix-en-Provence, France — 2CAMS, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
A new 5 MV accelerator mass spectrometry (AMS) system, fully dedicated to applied research, has been installed at CEREGE [1,2]. Since its acceptance test in March 2007, we have successfully established routine measurement conditions for the long-lived cosmogenic radionuclides 10Be and 26Al. Using 9Be carrier derived in our laboratory from phenakite crystals originating from a deep mine, we determined a background-level as low as 5x10−16 (10Be/9Be).
For 41Ca (extracted as CaF3−) and 129I, background levels are in the range of 2x10−14, whereas under optimum conditions the 36Cl background can reach 3x10−16 (36Cl/35Cl). The total transmission varies from 0.02 (36Cl with a post-stripping absorber foil) to 0.38 (26Al).
The main focus of applications has been on geological and environmental topics with the broad goal of using isotopic techniques to help understand the timing and rates of processes in the earth system. Work so far has included reconstruction of past climate, determination of the rate and timing of seismic activity, volcanic eruptions and rock falls.
 M. G. Klein et al., NIMB, submitted.  D. Bourlès et al., DPG Frühjahrstagung AK AMOP (2007) MS3.2.