We report the experimental observation of seed magnetic island formation by nonlinear three-wave coupling of magnetic island triplets. In this experiment, disruptive 2,1 islands are seeded by the coupling of 4,3 and 3,2 tearing modes to a central 1,1 sawtooth precursor. Three-wave interactions between these modes are conclusively identified by bispectral analysis, indicating fixed phase relationships in agreement with theory. This new observation of this seeding mechanism has important implications for future reactors that must operate in stable plasma equilibria, free of disruptive 2,1 islands.

中文翻译：

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托卡马克非线性三波相互作用的新古典撕裂模式播种

我们报告了通过磁岛三元组的非线性三波耦合对种子磁岛形成的实验观察。在这个实验中，破坏性的 2,1 岛是通过将 4,3 和 3,2 撕裂模式耦合到中央 1,1 锯齿前体来播种的。通过双谱分析最终确定了这些模式之间的三波相互作用，表明与理论一致的固定相位关系。对这种播种机制的这一新观察对未来的反应堆具有重要意义，这些反应堆必须在稳定的等离子体平衡中运行，没有破坏性的 2,1 岛。