1. Department of Quantum Science and Energy Engineering, Tohoku University, Aramaki-Aza-Aoba 01, Aoba-ku, Sendai 980-8579, Japan
2. Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Watanuki 1233, Takasaki 370-1292, Japan
3. National Institute of Radiological Science, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
4. TOKIN Machinery Corporation, Kohriyama 6-7-1, Taihaku-ku, Sendai 982-0003, Japan