1. Japan Aerospace Exploration Agency, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan, Advanced Engineering Service Co., Ltd., 1-6-1 Takezono, Tsukuba, Ibaraki, 305-0032, Japan, Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226, Japan, Toshiba Corporation, Power & Industrial Systems R & D Center, 8 Shinsugita-Cho, Isogo-Ku, Yokohama, Kanagawa 235-8523, Japan