AI 中文总结
该研究首次在EAST托卡马克核心区域观测到鱼骨驱动带状流的精细反向结构，发现其与此前模型预测不同。通过模拟揭示结构源于热离子和电子贡献的抵消，此机制此前未被捕捉，为调节湍流和改善核心约束提供了新途径。
AI 中文摘要
我们展示了在EAST托卡马克核心区域鱼骨驱动带状流的首次直接实验观测。与先前基于高能粒子排出机制的模型和模拟所预测的全局模式不同，观测到的流在q = 1有理面内呈现出精细尺度、径向反向的结构。在单个爆发中，流比鱼骨上升得更快且饱和更早，表明拍频驱动的非线性过程在早期占主导，而非高能粒子排出机制。全局非线性陀螺动力学模拟定量再现了观测到的径向分布，并揭示这种结构源于热离子和电子相当但相反贡献的抵消。先前理论框架未捕捉到这种抵消机制。这些发现表明鱼骨可产生具有独特径向拓扑的剪切流，为调节湍流和改善核心约束提供了一条有前景的途径。
英文摘要
We present the first direct experimental observation of fishbone-driven zonal flows in the core of the EAST tokamak. In contrast to the global pattern predicted by previous models and simulations based on the energetic-particle-expulsion mechanism, the observed flows exhibit a fine-scale, radially reversed structure inside the q = 1 rational surface. The flow rises faster and saturates earlier than the fishbone within a single burst, indicating that a beat-driven nonlinear process dominates the early stage rather than the energetic-particle-expulsion mechanism. Global nonlinear gyrokinetic simulations quantitatively reproduce the observed radial profile and reveal that this structure arises from the cancellation of comparable but opposite contributions from thermal ions and electrons. This cancellation mechanism is not captured in previous theoretical frameworks. These findings establish that the fishbone can generate sheared flows with a distinct radial topology, offering a promising pathway for regulating turbulence and improving core confinement.
