1. Graduate School of Engineering, Osaka University, 2–1, Yamadaoka, Suita, Osaka 565-0871, Japan
2. Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215, Japan
3. Department of Beam Physics, Division of Advanced Materials and Beam Science, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
4. Laser Accelerator R&D Team, RIKEN SPring-8 Center, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
5. Institute of Laser Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan