1. Research
Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1
O̅okayama, Meguro-ku, 152-8550 Tokyo, Japan
2. Institute of Resource
Ecology, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden, Germany
3. Department of Materials
and Life Science, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino-shi, 180-8633 Tokyo, Japan