1. Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Mukouyama, Naka-machi, Ibaraki-ken, 311-0193, Japan
2. Princeton Plasma Physics Laboratory, Princeton, NJ, 08543, U.S.A.
3. Vienna Office, Japan Atomic Energy Research Institute, Baumannstrasse 4-2-13, A1030, Wien, Austria 81-29-270-7453