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Esaka, Fumitaka; Magara, Masaaki
Mass Spectrometry Letters, 7(2), p.41 - 44, 2016/06
Secondary ion mass spectrometry (SIMS) is a promising tool to measure isotope ratios of individual uranium particles in environmental samples for nuclear safeguards. However, the analysis requires prior identification of a small number of uranium particles that coexist with a large number of other particles without uranium. In the present study, this identification was performed by scanning electron microscopy -energy dispersive X-ray analysis with automated particle search mode. The analytical results for an environmental sample taken at a nuclear facility indicated that the observation of backscattered electron images with 1000 magnification was appropriate to efficiently identify uranium particles. Lower magnification (less than 500) made it difficult to detect smaller particles of approximately 1 m diameter.
Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Lee, C. G.; Kimura, Takaumi
Mass Spectrometry Letters, 2(4), p.80 - 83, 2011/00
In this study, we applied secondary ion mass spectrometry (SIMS) and inductively coupled plasma mass spectrometry (ICP-MS) to the isotope ratio analysis of individual U-Pu mixed oxide particles. In the analysis of individual U-Pu particles prepared from mixed solution of uranium and plutonium standard reference materials, accurate U/U, Pu/Pu and Pu/Pu isotope ratios were obtained with both methods. However, accurate analysis of Pu/Pu isotope ratio was impossible, due to the interference of the Am peak to the Pu peak. In addition, it was indicated that the interference of the UH peak to the Pu peak has a possibility to prevent accurate analysis of plutonium isotope ratios. These problems would be avoided by a combination of ICP-MS and chemical separation of uranium, plutonium and americium in individual U-Pu particles.