The Institute of Scientific and Industrial Research, Osaka University


LAST UPDATE 2017/02/26

  • 研究者氏名
    Researcher Name

    誉田義英 Yoshihide HONDA
    准教授 Associate Professor
  • 所属
    Professional Affiliation

    The Institute of Scientific and Industrial Research, Osaka University

    Research Laboratory for Quantum Beam Science
  • 研究キーワード
    Research Keywords

    Positron Annihilation Spectroscopy
    Perfluorinated polymers
    Cray Minerals
    Electron Linear Accelerator
Research Subject
Evaluation of materials using positron annihilation spectroscopy

研究の背景 Background


The lifetimes of a positron and an ortho-positronium (o-Ps), which is a triplet of electron-positron bound state, in materials are used, in general, to get the information of defects or free volume with high sensitivity. However, in many functional materials or impurity-included ones, the annihilation process of positron/o-Ps lifetime would be greatly influenced by the presence of local electric field due to the functional groups and the impurities, implying that a subtle change relating to them can be detected with positron.

研究の目標 Outcome


The degradation process of polymer electrolyte membranes due to radicals in fuel cell has been investigated. Also, to find a proper manner to separate the fallout due to nuclear power plant accident, the relationship between structure difference and the trapping efficiency of radioisotopes in clay minerals of soil and the effective decontamination material are investigated mainly using positron annihilation spectroscopy (PAS).

研究図Research Figure

Fig.1. Deduced localization of orthopositronium by changing temperature and humidity. Fig.2. Localization of HO* in hydrophilic site deduced by pulse radiolysis (upper) and the destructions due to HO* and H* observed by PAS (lower). Fig.3.Doppler broadened spectra for different clay minerals (upper) and extraction rate of Cs (lower).

文献 / Publications

J. Power Sources, 196, 9856 (2011). Material Sci. Forum, 733, 53, (2012). J. Phys: Conf. Ser., 443, 012052, (2013).