1. CAS Key Laboratory of Geospace Environment and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
2. KTX Laboratory and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
3. Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
4. CAS Institute of Plasma Physics, Hefei, Anhui 230031, China