[1] Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China
[2] Natl Cheng Kung Univ, Inst Space Astrophys & Plasma Sci, Tainan 70101, Taiwan
[3] Univ Wisconsin, Dept Engn Phys, Madison, WI 53706 USA
[4] Forschungszentrum Julich, Assoc EURATOM FZJ, Trilateral Euregio Cluster, Inst Energy & Climate Res Plasma Phys, D-52425 Julich, Germany
[5] ITER Org, Plasma Operat Directorate, F-13115 St Paul Les Durance, France