1. Materials Science & Technology Division Tritium Science & Technology Group Los Alamos National Laboratory, MS C348 Los Alamos, New Mexico 87545, USA 505-667-1410
2. Department of Thermonuclear Fusion Research Japan Atomic Energy Research Institute Tokai Research Establishment Tokai-mura, Naka-gun, Ibaraki-ken, 319-11 Japan 0292-82-5577