Reduction of impurity confinement time by combined heating of LHW and ECRH in EAST

• 作者: Zong Xu Zhen-Wei Wu Ling Zhang Yue-Heng Huang Wei Gao Yun-Xin Cheng Xiao-Dong Lin Xiang Gao Ying-Jie Chen Lei Li Yin-Xian Jie Qing Zang Hai-Qing Liu EAST team
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（7）
• 所属期刊栏目: PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
• 页码范围: 391-401
• 页数: 11页
• 语种: 英文
• DOI: 10.1088/1674-1056/abe1a6

摘要

The core impurity confinement properties are experimentally investigated in the Experimental Advanced Supercon-ducting Tokamak (EAST) plasma heated by lower hybrid wave (LHW) and electron cyclotron resonance heating (ECRH)(LHW+ECRH).It is shown that the impurity confinement time (τimp) in the L-mode plasma jointly heated by LHW and ECRH is weakly dependent on electron density but strongly dependent on the heating power,thus it is shorter than that in LHW-only heated L-mode plasma with the similar plasma parameters.The combined heating of LHW and ECRH can reduce the collisionality and indicates a more effective heating method for core τimp reduction and normalized poloidal beta(βp) improvement.It should be emphasized that in this high βp operation window the small ELM regime can be accessed,and an L-mode level τimp (40 ms-80 ms) and high βN (～ 1.7) can be obtained simultaneously.It means that this typical small ELMy H-mode regime has an advantage in avoiding the serious tungsten accumulation,and will be competitive in future long-pulse steady-state and high-performance operation with high-Z material plasma-facing components.