1. College of Physical Science and Technology, Sichuan University, Chengdu 610064, People's Republic of China
2. Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
3. Southwestern Institution of Physics, Chengdu 610041, People's Republic of China
4. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
5. Fusion Simulation Center, Peking University, Beijing 100871, China