1. Frontier Technology R&D Division, Daihatsu Motor Company Ltd., Shiga 520-2593, Japan
2. Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
3. Quantum Beam Science Center, Japan Atomic Energy Agency, Sayo-gun, Hyogo 679-5148, Japan
4. Department of Applied Physics,
Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
5. Chemical
and Nuclear Engineering Department, Center for Emerging Energy Technologies, University of New Mexico, Albuquerque, New Mexico 87131, United States