Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
EP: Extraterrestrische Physik
EP 6: Poster
EP 6.1: Poster
Dienstag, 14. März 2006, 14:00–16:30, C
Non-destructive Trace Element Analysis of Presolar Stardust via XANES-PEEM — •Thomas Berg1, Pasqual Bernhard1, Jochen Maul1, Nicole Erdmann2, Christa Sudek3, Ulrich Ott3, and Gerd Schönhense1 — 1Universität Mainz, Institut für Physik, D-55099 Mainz — 2Universität Mainz, Institut für Kernchemie, D-55099 Mainz — 3Max-Planck-Institut für Chemie, D-55128 Mainz
Meteorites contain small amounts of presolar dust that survived the formation of the solar system without being affected by the isotope homogenisation. Therefore the isotopic composition not only of the bulk elements, but also of trace elements(1) is anomalous. Isotopic analysis via SIMS(2) / RIMS(3) often reveals the fingerprint of the nucleosynthetic s-processes that occurred in the grain’s origin star. The disadvantage of SIMS / RIMS, however, is that only a small number of isotopes can be investigated, because the sample grain is being destroyed. We present non-destructive synchrotron based XANES measurements using PEEM. Prior to isotopic analysis this technique is suitable for identification of interesting trace elements present in single stardust grains. In addition, XANES-PEEM provides information on the chemical environment in which the different elements occur within the particles. Supplementing TOF-SIMS measurements(4) confirming the XANES-PEEM results are also presented.
(1)E.Zinner,Annu.Rev.Earth Planet.Sci.26(1998)147
(2)K.K.Marhas,P.Hoppe,U.Ott,Meteorit.Planet.Sci.38(2003)A58
(3)M.R.Savina et al.,Geochim.Cosmichim.Acta67(2003)3201
(4)T.Stephan,Planetary Space Sci.49(2001)859