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Aoyama, Takafumi; Ito, Chikara; Okazaki, Koki; Harano, Hideki; Watanabe, Kenichi*; Iguchi, Tetsuo*
Journal of Nuclear Science and Technology, 45(Suppl.6), p.43 - 50, 2008/09
Times Cited Count:2 Percentile:16.93(Nuclear Science & Technology)no abstracts in English
Mashimo, Tsutomu; Ono, Masao; Huang, X.*; Iguchi, Yusuke*; Okayasu, Satoru; Kobayashi, Katsura*; Nakamura, Eizo*
Journal of Nuclear Science and Technology, 45(Suppl.6), p.105 - 107, 2008/09
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)It was observed that the concentration ratio Se/Se increased by % level in the specimen ultracentrifuged at 0.70.9 million G and at 300C(liquid state) or 190C (solid state), respectively. The present result is evidence of sedimentation of substitutional atoms in condensed matter via self-diffusion, and suggests its possible application to isotope separation by condensed matter centrifugation.
Nagasaki, Takanori*; Ito, Tsuyoshi*; Yoshino, Masahito*; Iwasaki, Kota*; Shiotani, Shinya*; Fukazawa, Hiroshi; Igawa, Naoki; Ishii, Yoshinobu*
Journal of Nuclear Science and Technology, 45(Suppl.6), p.122 - 127, 2008/09
Times Cited Count:5 Percentile:34.88(Nuclear Science & Technology)The neutron powder diffraction measurement was carried out at 10 K on the proton-conducting oxide BaZrInO with and without dissolved DO. Obtained diffraction data were analyzed by the Rietveld method and the maximum entropy method. It was found that deuterium atoms were located close the 12 site of the cubic perovskite structure with the space group -.
Koyama, Shinichi; Mitsugashira, Toshiaki*
Journal of Nuclear Science and Technology, 45(Suppl.6), p.55 - 64, 2008/09
Times Cited Count:9 Percentile:52.61(Nuclear Science & Technology)In order to evaluate the transmutation behavior of americium under fast neutron spectra, two irradiated Am samples (No.69, No.70) were analyzed by radiochemical methods. These samples were irradiated in the experimental fast reactor JOYO for 275 effective full power day by the fast neutron flux. Am, Am, Pu to Pu and Cm to Cm were clearly observed. The isotopic composition of Am exceeded 1.01 at% for sample No.69 and 1.48 at% for No.70. It was suggested that this difference came from the different rates of neutron capture reaction.
Ono, Masao; Iguchi, Yusuke*; Okayasu, Satoru; Esaka, Fumitaka; Kobayashi, Katsura*; Hao, T.; Bagum, R.*; Osawa, Takahito; Fujii, Kimio; Nakamura, Eizo*; et al.
Journal of Nuclear Science and Technology, 45(Suppl.6), p.108 - 110, 2008/09
Times Cited Count:1 Percentile:10.01(Nuclear Science & Technology)The atomic-scale graded structure of In-Pb alloy was formed by an ultracentrifuge experiment under conditions that a gravitational field of 810,000 G for 100 hours at 150C (solid state) in our previous study. The isotope fluctuation on this sample was measured using secondary ion mass spectrometer (SIMS). The ratio both Pb/Pb and In/In changed with positive gradient in the direction of centrifugal force approximately 1.2%. These isotope fluctuations were larger than that of starting state of natural state (In0.2%, Pb0.1%). These show that the sedimentation of isotopes occurred by solid centrifugation in this alloy, although achieved concentration gradients were small.
Atarashi-Andoh, Mariko; Koarashi, Jun; Ishizuka, Shigehiro*; Saito, Takeshi*; Hirai, Keizo*
no journal, ,
Soil organic matter (SOM) is the major reservoir of carbon in terrestrial ecosystems. Thus, to evaluate the CO flux from SOM is an important step toward estimating the effect of environmental change on the terrestrial carbon cycles. In this study, we estimated the contribution of different soil CO sources (SOM, litter and root) to CO flux from the forest floor based on measures of carbon isotopic ratios in SOM, litter, soil-respired CO and atmospheric CO in a cool-temperate deciduous forest.
Magara, Masaaki; Esaka, Fumitaka; Shinohara, Nobuo; Usuda, Shigekazu; Sakurai, Satoshi; Lee, C. G.; Yasuda, Kenichiro; Inagawa, Jun; Suzuki, Daisuke; Iguchi, Kazunari; et al.
no journal, ,
Information on isotope ratios of nuclear material is useful to know how it was produced and what purpose it was intended to use. On the other hand, one of the objectives for nuclear safeguards is to find out undeclared nuclear activities, therefore, the IAEA adopted the safeguards environmental sample analysis based on isotope ratio measurements of the nu-clear materials in 1995. Since 1998, analytical methods for safeguards environmental samples which are taken from nuclear facilities in the world wide by IAEA inspectors. Japan Atomic Energy Agency (JAEA) joined IAEA have been developed Analytical Laboratory Network for environmental analysis and are analyzing the environmental samples taken by the IAEA In the presentation, after introduction of the current status for the research and development activities at JAEA, techniques concerning isotope ratio measurement of plutonium in plutonium and MOX particles will be discussed.