The University of Texas at Austin, Austin, Texas 78712, USA.
MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2019 Mar 22;122(11):115001. doi: 10.1103/PhysRevLett.122.115001.
Plasma discharges with a negative triangularity (δ=-0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (β_{N}=2.7) and confinement characteristic of the high confinement mode (H_{98y2}=1.2) despite the absence of an edge pressure pedestal and no edge localized modes (ELMs). These inner-wall-limited plasmas have a similar global performance as a positive triangularity (δ=+0.4) ELMing H-mode discharge with the same plasma current, elongation and cross sectional area. For cases both of dominant electron cyclotron heating with T_{e}/T_{i}>1 and dominant neutral beam injection heating with T_{e}/T_{i}=1, turbulent fluctuations over radii 0.5<ρ<0.9 were reduced by 10-50% in the negative triangularity shape compared to the matching positive triangularity shape, depending on the radius and conditions.
在 DIII-D 托卡马克中创建了具有显著归一化β（β_{N}=2.7）和高约束模式（H_{98y2}=1.2）约束特性的具有负三角形度（δ=-0.4）的等离子体放电，尽管没有边缘压力峰和没有边缘局部模式（ELMs）。这些内壁限制等离子体具有与具有相同等离子体电流、拉长和横截面积的正三角形度（δ=+0.4）ELMing H 模式放电相似的整体性能。对于电子回旋共振加热占主导地位（T_{e}/T_{i}>1）和中性束注入加热占主导地位（T_{e}/T_{i}=1）的情况，与匹配的正三角形度形状相比，在半径 0.5<ρ<0.9 处的湍流波动减小了 10-50%，这取决于半径和条件。
