National Magnetic Confinement Fusion Science Program of China [2014GB108002, 2013GB107001]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [11205086, 11205053, 11375085, 11405082]; Construct Program of Fusion and Plasma Physics Innovation Team in Hunan Province, China [NHXTD03]; Natural Science Foundation of Hunan Province, ChinaNatural Science Foundation of Hunan Province [2015JJ4044]