Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak

Plasma discharges with a negative triangularity (δ=−0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (βN=2.7) and confinement characteristic of the high confinement mode (H98y2=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 Te/Ti>1 and dominant neutral beam injection heating with Te/Ti=1, turbulent fluctuations over radii 0.5

在DIII-D托卡马克装置中，已实现负三角度（δ=−0.4）的等离子体放电：该放电具有显著的归一化β（β_N=2.7），且具备高约束模（H-mode）的约束特性（H98y2=1.2），尽管其不存在边缘压强台基，也未出现边缘局域模（ELMs）。这类内壁限制型等离子体的整体性能，与等离子体电流、拉长比及横截面积一致的正三角度（δ=+0.4）带ELM的H模放电相近。对于电子温度与离子温度之比Te/Ti>1的主导电子回旋加热工况，以及Te/Ti=1的主导中性束注入加热工况，径向0.5处的湍流涨落