1. Department of Fusion Engineering Research, Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka-machi, Ibaraki-ken 311-01
2. Electron Tube & Devices Division, Toshiba Co., Ohtawara-shi, Tochigi 324
3. R&D Center, Toshiba Co., Ukishima, Kawasaki-shi, Kanagawa 210