title: Stable platinum isotope measurements in presolar nanodiamonds by TEAMS.
abstract: Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of198Pt/195Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.
authors.affiliation: University of Vienna, Faculty of Physics, VERA Laboratory, Währinger Strasse 17, A-1090 Vienna, Austria ; Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, Canberra, Australia ; Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Wallner
authors.forename: K
authors.initials: K
authors.lastname: Melber
authors.forename: S
authors.initials: S
authors.lastname: Merchel
authors.forename: U
authors.initials: U
authors.lastname: Ott
authors.forename: O
authors.initials: O
authors.lastname: Forstner
authors.forename: R
authors.initials: R
authors.lastname: Golser
authors.forename: W
authors.initials: W
authors.lastname: Kutschera
authors.forename: A
authors.initials: A
authors.lastname: Priller
authors.forename: P
authors.initials: P
authors.lastname: Steier
keywords: Nanodiamonds; Presolar grains; Pt; Super novae; TEAMS; Trace elements
references.citation: Science. 2004 Jan 30;303(5658):649-52
references.pmid: 14752154
references.citation: Nucl Instrum Methods Phys Res B. 2013 Jan;294(2-2):160-164
references.pmid: 23565016
references.citation: Nucl Instrum Methods Phys Res B. 2013 Jan;294(2-2):496-502
references.pmid: 23565017
references.citation: Phys Rev Lett. 2014 May 16;112(19):192501
references.pmid: 24877933