1. Shanghai EBIT Lab, Key Laboratory of Nuclear Physics and Ion-Beam Application, Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433, China
2. Science and Technology on High Power Microwave Laboratory, Institute of Applied Electronics, CAEP, Mianyang 621900, China
3. National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China