We calculate Alfvén eigenmodes within a magnetic island (MiAE) which have been conjectured over a decade ago. Starting from a cylindrical plasma equilibrium, we calculate the complete metric of the island interior assuming an iota profile with a constant shear for Wendelstein 7-X parameters. Then, we solve the resulting Magneto-Hydrodynamic equations inside the island optionally considering Finite Larmor Radius corrections. We find various eigenmodes in the lowest gaps for n = 0. The eigenmode with the lowest frequency shows a weakly non-linear dependence on the island width which deviates considerably from an earlier estimate.

中文翻译：

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磁岛内的剪切阿尔芬波

我们计算了十多年前推测的磁岛 (MiAE) 内的阿尔芬本征模态。从圆柱等离子体平衡开始，假设 Wendelstein 7-X 参数的 iota 剖面具有恒定剪切力，我们计算岛内部的完整度量。然后，我们求解岛内产生的磁流体动力学方程，可选地考虑有限拉莫尔半径校正。我们在最低间隙中发现了各种本征模态n = 0。最低频率的本征模显示出对岛宽度的弱非线性依赖性，这与早期的估计有很大偏差。