1. Graduate School of Engineering; Shinshu University; Nagano Japan
2. Department of Helical Plasma Research, National Institute for Fusion Science, National Institutes of Natural Sciences; Toki Japan
3. Graduate School of Engineering; Nagoya University; Nagoya Japan
4. Graduate School of Science and Engineering; Yamagata University; Yonezawa Japan
5. Department of Fusion Science; The Graduate University for Advanced Studies, SOKENDAI; Toki Japan
6. Department of Mechanical Engineering and Science, Graduate School of Engineering; Kyoto University; Kyoto Japan