1. University of South China, School of Electrical Engineering, Hengyang 421001, People’s Republic of China
2. Lanzhou University, Lanzhou, 730000, People’s Republic of China
3. Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, People’s Republic of China
4. University of South China, School of Nuclear Science and Technology, Hengyang 421001, People’s Republic of China