Study of the mechanism of ITB formation and sustainment with optimized q profiles in ELMy H mode discharges on the EAST. (27th August 2021)

• Record Type: Journal Article
• Authors: Chu, Y Q; Liu, H Q; Zhang, S B; Jie, Y X; Lian, H; Wu, M Q; Zhu, X; Wu, C B; Xu, L Q; Wang, Y F; Wang, S X; Zhang, T; Yang, Y; Hanada, K; Lyu, B; Li, Y Y; Zang, Q
• Other Names: collab.
• Is Part Of: Plasma physics and controlled fusion. Volume 63:Number 10(2021)
• Publication Date: 2021-08-27
• Subjects: high normalized beta -- ITB -- q profile -- MHD; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/ac1b1f
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: Recently, improved confinement plasma with the internal transport barrier (ITB) on the Experimental Advanced Superconducting Tokamak has been achieved through extensive experiments in high β N scenario development. ELMy H-mode plasmas are heated by lower hybrid wave and neutral beam injection, with B T = 1.6 T, I p = 400/450 kA and q 95 in the range 3.7–4.6. ITB with optimized reversal q profiles and central flat q profiles are observed in these H-mode plasmas, which lead to better confinement. The electron temperature ITB, ion temperature ITB, and electron density ITB exhibit different characteristics. In this paper, the formation and sustainment of ITB on n e channel has great relationship with magnetohydrodynamics (MHD) behaviors. For T e channel, q profile has a dominating effect. Reversal magnetic shear and MHD behaviors are both effective in T i ITB formation. Suppression of turbulence in the ITB region is the common reason on all the channels. In addition, the power threshold of the ITB formation should be concentrated on electrons and ions separately. The results of this study can widen the understanding of ITB and be helpful in exploring better candidate operational scenarios for future fusion devices.