1. Research Center for Energy and Environmental Materials, National Institute for Materials Science, Tsukuba, Japan
2. National Institute for Materials Science, Tsukuba, Japan
3. Sophia University, Tokyo, Japan
4. Kobe Steel Ltd., Kobe, Japan
5. Furukawa Electric Company, Ltd., Tochigi, Japan
6. High Field Laboratory for Superconducting Materials, Institute for Material Research, Tohoku University, Sendai, Japan
7. Rokkasho Fusion Institute, National Institutes for Quantum Science and Technology, Aomori, Japan