Affiliation: | (1) Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370–12, Japan(Fax: +81-273-46-9687, E-mail: itohq@taka.jaeri.go.jp), JP;(2) Institute of Materials Science, University of Tsukuba, 1–1–1 Tennodai, Tsukuba, Ibaraki 305, Japan, JP;(3) Electrotechnical Laboratory, 1–1–4 Umezono, Tsukuba, Ibaraki 305, Japan, JP |