Impact of T_(i)/T_(e )ratio on ion transport based on EAST H-mode plasmas  

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)

机构地区：[1]Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,People’s Republic of China [2]University of Science and Technology of China,Hefei 230026,People’s Republic of China [3]Forschungszentrum Jülich GmbH,Institut für Energie-und Klimaforschung-Plasmaphysik,Partner of the Trilateral Euregio Cluster(TEC),Jülich 52425,Germany

出　　处：《Plasma Science and Technology》2024年第4期68-78,共11页等离子体科学和技术（英文版）

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。

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.

关 键 词：ion temperature clamping TRANSPORT neutral beam injection STIFFNESS internal transport barrier 

分 类 号：TL631.24[核科学技术—核技术及应用]