A New Path to Improve High βp Plasma Performance on EAST for Steady-State Tokamak Fusion Reactor*Supported by the National Magnetic Confinement Fusion Science Program of China under Grant No. 2015GB103000. (April 2020)

• Record Type: Journal Article
• Authors: Wan 万, Baonian 宝年
• Other Names: collab.
• Is Part Of: Chinese physics letters. Volume 37:Number 4(2020)
• Publication Date: 2020-04
• Subjects: 52.75.-d -- 52.77.Fv; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1088/0256-307X/37/4/045202
• Languages: English
• ISSNs: 0256-307X

Abstract

Abstract : High β p scenario is foreseen to be a promising candidate operational mode for steady-state tokamak fusion reactors. Dedicated experiments on EAST and data analysis find that density gradient ∇ n is a control knob to improve energy confinement in high β p plasmas at low toroidal rotation as projected for a fusion reactor. Different from previously known turbulent stabilization mechanisms such as E × B shear and Shafranov shift, high density gradient can enhance the Shafranov shift stabilizing effect significantly in high β p regime, giving that a higher density gradient is readily accessible in future fusion reactors with lower collisionality. This new finding is of great importance for the next-step fusion development because it may open a new path towards even higher energy confinement in the high β p scenario. It has been demonstrated in the recent EAST experiments, i.e., a fully non-inductive high β p (∼2) H-mode plasma (H 98 y 2 ≥ 1.3 ) has been obtained for a duration over 100 current diffusion times, which sets another new world record of long-pulse high-performance tokamak plasma operation with the normalized performance approaching the ITER and CFETR regimes.