RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 59 , Issue 8
Showing 1-8 articles out of 8 articles from the selected issue
Note
  • Tetsuo YOSHIDA, Takayuki HIRONIWA, Toshiki MASUMIZU, Hideyuki HARA, Ma ...
    2010 Volume 59 Issue 8 Pages 463-469
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    We focus on dried fruits containing crystalline sucrose chiefly, and study a method for identification of sucrose-radicals in ESR spectra of irradiated dried fruits. We evaluated g-values and widths of ESR signals of irradiated dried fruits and sucrose respectively. The result showed it might be possible to identify sucrose-radicals by g-values and widths.
    We tried the establishment of criteria for the judgment that the sample has been irradiated. As a result, criteria may be established by normalized peak height of ESR signals. The peak height can be normalized by using standard irradiated alanine pellets.
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Materials(Data)
  • Sadaaki MIYAKE, Terumitsu YOSHIDA, Kunihiko TAKAHASHI, Masao IIJIMA, K ...
    2010 Volume 59 Issue 8 Pages 471-475
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    Concentrations of 134Cs, 137Cs and 40K in 73 supplements marketed in Japan were measured by gamma-ray spectrometry.
    In all supplements, 134Cs was not detected. On the other hand, 137Cs was detected in 9 supplements, and the concentrations of 137Cs in them were in the range of 2.3-190 Bq/kg. There was a tendency that concentrations of 137Cs in supplements made from materials accumulating 137Cs, such as mushrooms and blueberries, were high. Furthermore, 40K was detected in 56 supplements at levels of 17.6-11600Bq/kg.
    The committed effective dose of 137Cs in adults by annually taking supplements was estimated to be about 2.9μSv.
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Serial Lectures
Fundamentals and Applications of Neutron Diffraction(Fundamentals7)
  • Kenji OHOYAMA
    2010 Volume 59 Issue 8 Pages 477-490
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    For magnetic structure refinement of bulk materials, the neutron diffraction technique is the most reliable probe. In this short article, basic information of magnetic structure refinement by powder neutron diffraction;in particular, actual process of data analysis will be presented with real data. First, the author will explain some typical commensurate and incommensurate structures, and how the structure represent by propagation vector k, which is the one of the most important value for magnetic structure refinement. The author will show the magnetic structure factor, and explain the meanings of each factor of which the magnetic structure factor consists. Each process from neutron diffraction experiments to the analysis for practical magnetic structure refinements will be explained in the case of the rare earth compound TmB2C2. In the section, information on some diffractometers in Japan which are suitable for magnetic structure refinements will be given. Finally, information on some important and powerful analysis softwares for Rietveld analysis and a quite sophisticated technique, the representation analysis technique, will be presented.
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Fundamentals and Applications of Neutron Diffraction(Applications18)
  • Hiroaki KATO
    2010 Volume 59 Issue 8 Pages 491-500
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    As an example of application of neutron diffraction, magnetic properties of high-performance permanent magnets were reviewed, laying emphasis on rare-earth containing magnets. After introducing a development history of permanent magnets in the last century, basic properties and origin of magnetic anisotropy in ferromagnets were explained in terms of crystalline-electric-field interaction acting on a rare-earth ion. Main part of this article was devoted to a description of the strongest Nd-Fe-B magnet, main phase of which has been assigned to be Nd2Fe14B intermetallic compound by powder neutron diffraction experiments. Structural and magnetic properties in a series of Nd2Fe14B-type compounds were described systematically, including inelastic neutron scattering, small-angle neutron scattering, and high-field magnetization experiments on single crystal samples. Recent issue of Dy-containing Nd-Fe-B magnets for applications in a driving motor of the hybrid electric vehicle was mentioned in the final chapter, which consequently motivated and stimulated a research to enhance the coercivity of the Nd-Fe-B magnets with less Dy content.
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Fundamentals and Applications of Neutron Diffraction(Applications19)
Fundamentals and Applications of Neutron Diffraction(Applications20)
  • Hiroyuki NOJIRI
    2010 Volume 59 Issue 8 Pages 509-517
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    Recent progresses of neutron diffraction under high magnetic fields are introduced. A compact pulsed magnet is installed in a reactor and experiments up to 30T can be achieved without modification of conventional spectrometers. In pulsed neutron source, pulsed magnet system up to 50T has been developed. The first feasibility study was successfully performed up to 40T. Those advances will open a new stage in the use of neutron diffraction in high magnetic fields in both fundamental and applied sciences.
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Fundamentals and Applications of Neutron Diffraction(Applications21)
  • Taka-hisa ARIMA, Hiroyuki KIMURA
    2010 Volume 59 Issue 8 Pages 519-527
    Published: 2010
    Released: August 27, 2010
    JOURNALS OPEN ACCESS
    Magnetic structure of typical multiferroic materials RMnO3 and RMn2O5 (R:rare earth) has been investigated by neutron diffraction. Magnetic structure analysis using single crystal revealed that both the materials have a cycloidal magnetic structure, where ferroelectricity arises. Polarized neutron diffraction under electric field found the one-to-one correspondence between the direction of cycloidal rotation (spin chirality) and the direction of the electric polarization, evincing that the electric polarization is directly induced by the cycloidal magnetic order.
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Fundamentals and Applications of Neutron Diffraction(Applications22)
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