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Tenth International Conference on Accelerator Mass Spectrometry, Berkeley : États-Unis
A search for supernova produced $^{244}$Pu in a marine sediment
G. Raisbeck1, T. Tran1, D. Lunney1, C. Gaillard2, S. Goriely, C. Waelbroeck, F. Yiou1

We describe here the chemical and AMS procedures that we have developed to look for $^{244}$Pu in marine sediments. This study was motivated by the report of Knie et al. [K. Knie, G. Korschinek, T. Faestermann, E.A. Dorfi, G. Rugel, A.Wallner, Phys. Rev. Lett. 93 (2004) 171103] for observation of 60Fe in a ferromanganese crust, which they have interpreted as resulting from the explosion of a supernova near the solar system $\sim$ 2.8 My ago. A novel aspect of the AMS procedure is the use of various Mo isotopes as “pilot” beams, which allow us to tune the machine for the various Pu isotopes, without the necessity of using enriched Pu standards, thus minimizing the risk of $^{244}$Pu contamination. These techniques have been tested on an IAEA marine sediment containing nuclear weapons contaminated $^{239}$Pu and then applied to an Indian Ocean sediment over the period 2.4–4.0 My.
1 :  CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
2 :  DRS-IPHC - Département Recherches Subatomiques
Accelerator mass spectrometry – 244Pu – Supernova