1. CAS Key Laboratory of Geospace Environment and Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei 230026, China
2. National Tokamak Fusion Program, Islamabad 3329, Pakistan
3. KTX Laboratory and Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei 230026, China
4. Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA