Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
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Direct detection of live 60Fe and 244Pu on Earth as a monitor for recent heavy-element nucleosynthesis
Observation and detection of freshly produced nuclides provides a direct clue for understanding stellar nucleosynthesis. In particular, radionuclides can act as radioactive clocks for their recent production. Previous measurements in deep-sea manganese crusts and sediments for extraterrestrial 60Fe (t1/2=2.6 Myr) at TU Munich  and for 244Pu (t1/2=81 Myr) at Munich , Hebrew University  and the VERA laboratory, Vienna  applied accelerator mass spectrometry (AMS), the most sensitive technique for detecting the expected small traces of interstellar material in terrestrial archives.
Recently, we have started a program at the ANU to follow-up a discovery of a 60Fe excess in an ocean crust sample pointing to a recent close-by supernova (SN) . A substantial beamtime devoted to 60Fe has resulted in an exceptional sensitivity of 60Fe/Fe below 10-16. We have searched for a SN-signal in three deep-sea sediment cores (Indian Ocean). We will present first data for 60Fe allowing high time resolution and will relate it to potential recent SNe.
In addition, we have re-measured with an independent method the 60Fe half-life via 60Fe AMS measurements that allows us addressing the discrepancy of the two existing half-live values [5,6].
 K. Knie et al., PRL93 (2004), C. Fitoussi et al., PRL101 (2008).
 C. Wallner et al. New Astr. Rev. 48 (2004)
 M. Paul et al, ApJL 558 (2001)
 A. Wallner et al., submitted
 G. Rugel et al., PRL103 (2009)
 W. Kutschera et al., NIM B5 (1984)
Keywords: accelerator mass spectrometry; supernova; radionuclide
XIII Nuclei in the Cosmos, 07.-11.07.2014, Debrecen, Ungarn