摘要
At the EAST tokamak, the ion temperature(T_(i)) is observed to be clamped around 1.25 keV in electron cyclotron resonance(ECR)-heated plasmas, even at core electron temperatures up to 10 keV(depending on the ECR heating power and the plasma density). This clamping results from the lack of direct ion heating and high levels of turbulence-driven transport. Turbulent transport analysis shows that trapped electron mode and electron temperature gradient-driven modes are the most unstable modes in the core of ECR-heated H-mode plasmas. Nevertheless, recently it was found that the T_(i)/T_(e)ratio can increase further with the fraction of the neutral beam injection(NBI) power, which leads to a higher core ion temperature(Ti0). In NBI heating-dominant H-mode plasmas, the ion temperature gradient-driven modes become the most unstable modes.Furthermore, a strong and broad internal transport barrier(ITB) can form at the plasma core in high-power NBI-heated H-mode plasmas when the T_(i)/T_(e)ratio approaches ~1, which results in steep core Teand Tiprofiles, as well as a peaked neprofile. Power balance analysis shows a weaker Teprofile stiffness after the formation of ITBs in the core plasma region, where Ticlamping is broken,and the core Tican increase further above 2 keV, which is 80% higher than the value of Ticlamping in ECR-heated plasmas. This finding proposes a possible solution to the problem of Ticlamping on EAST and demonstrates an advanced operational regime with the formation of a strong and broad ITB for future fusion plasmas dominated by electron heating.
作者
刘建文
臧庆
梁云峰
陈佳乐
邬潇河
Alexander KNIEPS
扈嘉辉
金仡飞
张斌
储宇奇
刘海庆
吕波
段艳敏
李妙辉
陈颖杰
龚先祖
the EAST Team
Jianwen LIU;Qing ZANG;Yunfeng LIANG;Jiale CHEN;Xiaohe WU;Alexander KNIEPS;Jiahui HU;Yifei JIN;Bin ZHANG;Yuqi CHU;Haiqing LIU;Bo LYU;Yanmin DUAN;Miaohui LI;Yingjie CHEN;Xianzu GONG;the EAST Team(Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,People’s Republic of China;University of Science and Technology of China,Hefei 230026,People’s Republic of China;Forschungszentrum Jülich GmbH,Institut für Energie-und Klimaforschung–Plasmaphysik,Partner of the Trilateral Euregio Cluster(TEC),Jülich 52425,Germany)
基金
supported by National Natural Science Foundation of China(No.12135015)
the Users with Excellence Program of Hefei Science Center,CAS(No.2021HSCUE012)
the National Key R&D Program of China(No.2022Y FE03010003)
the Major Science and Technology Infrastructure Maintenance and Reconstruction Projects of the Chinese Academy of Sciences 2021
the Special Funds for Improving Conditions for Scientific Research in National Scientific Institutions 2022
the China Scholarship Council。