1. Institute of Science and EngineeringShimane University Shimane 690‐8504 Japan
2. Research Institute for Applied MechanicsKyushu University Fukuoka 816‐8580 Japan
3. Research Center for Plasma TurbulenceKyushu University Fukuoka 816‐8580 Japan
4. Interdisciplinary Graduate School of Engineering SciencesKyushu University Fukuoka 816‐8580 Japan
5. National Institute for Fusion Science Gifu 502‐5292 Japan
6. Faculty of Arts and ScienceKyushu University Fukuoka 819‐0395 Japan
7. Institute of Science and Technology ResearchChubu University Aichi 487‐8501 Japan
8. Department of Innovative Energy Science and Engineering, Graduate School of EngineeringChubu University Aichi 487‐8501 Japan