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  • 1 Kyoto University Research Reactor Institute Kumatori-cho, Sennan-gun Osaka 590-0494 Japan
  • | 2 Nihon University College of Humanities and Sciences Sakurajosui, Setagaya-ku Tokyo 156-8550 Japan
  • | 3 Tokyo Metropolitan University Department of Chemistry, Graduate School of Science Hachioji, Tokyo 192-0397 Japan
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Chemical composition of 15 magnetic spherules collected from deep sea sediment was determined by instrumental neutron activation analysis (INAA) under two different irradiation conditions using the Kyoto University Reactor (KUR). Based on their chemical composition, nine spherules were judged to be of extraterrestrial origin. The differences in the chemical composition of the nine spherules are discussed in terms of condensation temperatures for the elements. Comparing the detection limits derived from INAA under two different irradiation conditions, the sensitivity for INAA using KUR is discussed.