[1] Cent Res Inst Elect Power Ind, Radiat Safety Res Ctr, 2-11-1 Iwado Kita, Komae, Tokyo 2018511, Japan
[2] Wakasa Wan Energy Res Ctr, Dept Res & Dev, Proton Med Res Grp, Tsuruga, Fukui, Japan
[3] High Energy Accelerator Res Org KEK, Photon Factory, Inst Mat Struct Sci, Tsukuba, Ibaraki, Japan
[4] Japan Atom Energy Agcy, Quantum Beam Sci Ctr, Res Grp Radiat & Biomol Sci, Tokai, Ibaraki, Japan