[1] Joint Inst Nucl Res, Dubna 141980, Moscow Region, Russia
[2] Jozef Stefan Inst, Ljubljana 1001, Slovenia
[3] Univ Tokyo, Dept Quantum Engn & Syst Sci, Tokyo 1138656, Japan
[4] Univ Maribor, Fac Civil Engn, SLO-2000 Maribor, Slovenia
[5] Nihon Univ, Coll Ind Technol, Lab Phys Sci, Narashino, Chiba 275, Japan
[6] Natl Inst Radiol Sci, Div Accelerator Phys & Engn, Inage Ku, Chiba 2638555, Japan