1. National Institutes for Quantum and Radiological Science and Technology, Rokkasho, Aomori 039-3212, Japan
2. Japan Atomic Energy Agency, CCSE, 178-4-4 Wakashiba, Kashiwa, Chiba, Japan
3. Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, 606-8501 Kyoto, Japan
4. Fraunhofer Institute for Industrial Mathematics (ITWM), 67663 Kaiserslautern, Germany
5. Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
6. CEA, IRFM, F-13108 St. Paul-lez-Durance Cedex, France