Spontaneous current relaxation in NBI heated plasmas on EAST  

作　　者：Weixing DING Haiqing LIU Jinping QIAN Shoubiao ZHANG D L BROWER Zhiyong ZOU Weiming LI Yao YANG Long ZENG Jinlin XlE Ping ZHU Changxuan YU Ting LAN Shouxin WANG Hui LIAN Yinxian JIE Liqun HU and Baonian WAN 丁卫星;刘海庆;钱金平;张寿彪;D L BROWER;邹志勇;李维明;杨曜;曾龙;谢锦林;朱平;俞昌旋;兰婷;王守信;连辉;揭银先;胡立群;万宝年(University of California Los Angeles;University of Science and Technology of China;Institute of Plasma Physics,Chinese Academy of Sciences)

机构地区：[1]University of California Los Angeles,Los Angeles,California 90095,United States of America [2]Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,People＇s Republic of China [3]University of Science and Technology of China,Hefei 230026,People＇s Republic of China

出　　处：《Plasma Science and Technology》2018年第9期3-7,共5页等离子体科学和技术（英文版）

基　　金：supported by National Key R&D Program of China,contract No.2014GB106002;partly supported by the US D.O.E.contract DESC0010469;partly supported by the Major Program of Development Foundation of Hefei Center for Physical Science and Technology with contract No.2016FXZY007

摘　　要：We report on current profile evolution in EAST NBI driven plasmas where two neutral beams are injected,one during the current ramp phase and the second during flattop.At the end of the current ramp phase,it is found that a flat q profile with q0-1 is achieved with low magnetic shear in the core.It is observed that plasma current and density both relax much faster than resistive time,even in the absence of sawtooth activity when H-L transition occurs.Density fluctuations associated with magnetic perturbations（3/2） as a precursor to the H-L transition are observed.It is likely that these modes play a role in fast current transport.We report on current profile evolution in EAST NBI driven plasmas where two neutral beams are injected,one during the current ramp phase and the second during flattop.At the end of the current ramp phase,it is found that a flat q profile with q0-1 is achieved with low magnetic shear in the core.It is observed that plasma current and density both relax much faster than resistive time,even in the absence of sawtooth activity when H-L transition occurs.Density fluctuations associated with magnetic perturbations（3/2） as a precursor to the H-L transition are observed.It is likely that these modes play a role in fast current transport.

关 键 词：current transport NBI plasma density fluctuations magnetic perturbations EAST 

分 类 号：TL631.24[核科学技术—核技术及应用]