1. Japan Atomic Energy Research Institute, Department of Reactor Engineering Tokai Research Establishment, Tokai-mura, Naka-gun, Ibaraki-ken, 319-11 Japan
2. University of California, Los Angeles School of Engineering and Applied Science Mechanical, Aerospace, and Nuclear Engineering Department Los Angeles, California 90095
3. Argonne National Laboratory, Fusion Power Program Building 205, 9700 South Cass A venue, Argonne, Illinois 60439