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负三角形变位形下的托卡马克具有更低的湍流输运和更好的能量约束, 被认为是未来聚变堆一个更好的选择. 为了探索负三角形变位形下高能量粒子激发不稳定性的特征, 使用动理学-磁流体混合模型程序M3D-K开展了此位形下高能量离子激发鱼骨模的线性不稳定性和非线性演化的模拟研究. 基于类EAST参数条件, 模拟发现负三角形变解稳理想内扭曲模不稳定性, 但会致稳鱼骨模不稳定性. 非线性模拟发现在没有磁流体非线性效应时, 负三角形变位形下的鱼骨模更不容易饱和, 可能的解释是相比于正三角形变位形, 在负三角形变位形下的高能量离子轨道更接近与芯部, 因而更容易驱动鱼骨模不稳定性. 这些结果表明考虑高能量粒子激发的鱼骨模不稳定性后, 负三角形变位形相比于正三角形变位形并没有明显优势.The discharges with negative triangularity have lower turbulence induced transport and better energy confinement, so the tokamak with negative triangularity is recognized to be a better choice for future fusion device. In order to explore the features of the energetic particle driven instabilities with negative triangularity, the kinetic-magnetohydrodynamic hybrid code M3D-K is used to investigate the linear instability and nonlinear evolution of the fishbone driven by energetic ions with different triangularity. Based on EAST-like parameters, it is found that the negative triangularity destabilizes the ideal internal kink mode, but stabilizes the fishbone instability. Nonlinear simulations show that the fishbone instability with negative triangularity is hard to saturate without fluid nonlinearity. The possible explanation is that the orbits of fast ions are located more centrally with negative triagularity, so the energy exchange between energetic ions and the fishbone is more efficient than that with positive triangularity. These simulation results demonstrate that the negative triangularity does not have an obvious advantage over the positive triangularity, with the fishbone driven by energetic particles considered.
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Keywords:
- negative triangularity /
- fast ions /
- fishbone instability








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