1. National Institute for Fusion Science, Toki 509-5292, Japan
2. Kyushu University, Kasuga 816-8580, Japan
3. Nagoya University, Faculty of Engineering, Nagoya 464-8601, Japan
4. Graduate University for Advanced Studies, Hayama 240-0162, Japan
5. Kyoto University, Institute of Advanced Energy, Uji 611-0011, Japan
6. University of Tokyo, Tokyo, Japan
7. University of Tsukuba, Tsukuba, Japan
8. Institute of Plasma Physics, Academia Sinica, Hefei 230031, P.R. China
9. Korea Atomic Energy Research Institute, Daejeon 305-600, Korea Rep.