摘要
The double tearing mode(DTM)in a high βN(βN>1.5)discharge with internal transport barrier on EAST was investigated.A 15 kHz tearing mode(TM)(m≥3,n=3)appears at outer q=2 surface at first,which is stable in the highβN phase.Then a 2 kHz TM(m=2,n=1)occurs at inner q=2 surface.Soon after,high βN collapsed with the crash of ELM,and DTM formed during the collapse of βN.The positions of the two islands of the DTM are consistent with the q=2 surface.The temperature fluctuations are the strongest between the two magnetic islands.A statistical analysis of high βN discharges operating with the reversed magnetic shear configuration in the EAST 2015-2018 campaign revealed the existence of the DTM in many discharges.During the DTM phase,all βN are reduced by 10%-30% within 0.1 s.However,there are two different βN behaviors thereafter-with and without βN recovery.Studying the physical mechanism of βN recovery during the DTM phase will benefit steady-state operation with reversed shear configurations in the future.
作者
吴茗甫
刘子奚
张涛
钟富彬
李恭顺
向皓明
耿康宁
叶凯萱
黄佳
文斐
王嵎民
韩翔
张寿彪
刘海庆
李国强
庄革
高翔
Mingfu WU;Zixi LIU;Tao ZHANG;Fubin ZHONG;Gongshun LI;Haoming XIANG;Kangning GENG;Kaixuan YE;Jia HUANG;Fei WEN;Yumin WANG;Xiang HAN;Shoubiao ZHANG;Haiqing LIU;Guoqiang LI;Ge ZHUANG;Xiang GAO
基金
the National Key R&D Program of China(Nos.2015GB110001,2017 YFE0300501 and 2017YFE0301205)
National Natural Science Foundation of China(Nos.11505221,11675211,11805136,11875289,11975230).