1. An upper limit to interstellar 244Pu abundance as deduced from radiochemical search in deep-sea sediment: An account.
- Author
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Paul, M., Valenta, A., Ahmad, I., Berkovits, D., Bordeanu, C., Ghelberg, S., Hashimoto, Y., Hershkowitz, A., Jiang, S., Nakanishi, T., and Sakamoto, K.
- Subjects
INTERSTELLAR medium ,COSMIC abundances ,PLUTONIUM isotopes ,MARINE sediments ,RADIOCHEMICAL research - Abstract
We report here a search for the “live”
244 Pu in 1 kg deep-sea dry sediment collected in 1992 in the North Pacific. After a 546 day alpha-counting of a Pu fraction chemically separated from the alkaline-fused sediment sample at Kanazawa University, AMS analysis was performed at Hebrew University and Weizmann Institute. Only one count of244 Pu with no background ions was detected, indicating no excess over the expected stratospheric man-made fallout. A limit of 0.2 atoms of244 Pu cm−2 ·y−1 for extra terrestrial deposition was set under reasonable assumptions and it was then concluded from this result and the available data on interstellar medium (ISM) that the abundance of244 Pu in the ISM is less than 2·10−11 g244 Pu (g·ISM)−1 . Implications of the present result are discussed. [ABSTRACT FROM AUTHOR]- Published
- 2007
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