[1] Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China
[2] Univ Cassino, Univ Naples Federico II, CREATE, I-80125 Naples, Italy
[3] Univ Napoli Parthenope, I-80125 Naples, Italy
[4] Univ Sci & Technol China, Sch Nucl Sci & Technol, Hefei 230026, Peoples R China
[5] CR Frascati, ENEA UnitaTecn Fus, I-00044 Rome, Italy