1. School of Nuclear Science and Technology, University of South China, Hengyang, Hunan 421001, People's Republic of China
2. FSC and State Key Lab of Nuclear Physics and Technology, Department of Physics, Peking University, Beijing 100871, People's Republic of China
3. Southwestern Institute of Physics, P O Box 432, Chengdu 610041, People's Republic of China
4. Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310058, People's Republic of China
5. School of Environmental Protection and Safety Engineering, University of South China, Hengyang 421001, People's Republic of China