微撕裂模的线性回旋动理学模拟：局部与全局对比
Linear Gyrokinetic Simulations of Micro-tearing Mode: Local versus Global
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中文总结 AI 辅助
该研究用GENE代码系统比较微撕裂模的局部与全局线性回旋动理学模拟，涵盖多样等离子体参数。发现全局模拟有独特模式，电流层宽度是决定全局效应关键因素，核心区局部与全局结果一致，台基区有偏差，解释了两者模拟差异。
中文摘要 AI 辅助
使用GENE代码对微撕裂模（MTM）的局部和全局线性回旋动理学模拟进行了系统比较。分析涵盖了不同的等离子体参数，包括具有正常和弱磁剪切的核心区域以及具有强等离子体不均匀性的台基区域。全局模拟揭示了一种以‘奇偶混合’模式结构为特征的独特MTM类型，它会被捕获电子显著地激发。此外，与静电漂移波不稳定性不同，电流层宽度（$\Delta_c$）被确定为决定全局效应重要性的关键因素。核心区域的MTM表现出台状特征，$\Delta_c$较窄，导致局部和全局结果高度一致。然而，在台基区域，陡峭的压力梯度使$\Delta_c$变宽，当$\Delta_c$与等离子体压力梯度尺度长度可比时会产生定量偏差。对于高$n$的MTM，$\Delta_c$可能超过相邻模有理面之间的距离。由此产生的电流层重叠增强了环向模耦合效应，这解释了局部和全局模拟之间观察到的显著差异。
英文摘要
A systematic comparison of local and global linear gyrokinetic simulations of micro-tearing modes (MTMs) is performed using the GENE code. The analysis spans diverse plasma parameters, including the core regions with normal and weak magnetic shear, as well as the pedestal region with the strong plasma non-uniformity. The global simulations reveal a distinct MTM type characterized by a `parity mixing' mode structure, which can be significantly destabilized by trapped electrons. Moreover, in contrast to electrostatic drift wave instabilities, the current layer width ($ Δ_c $) is identified as the crucial factor determining the importance of global effects. The MTM in the core region exhibits the slab-like feature with narrow $ Δ_c $, leading to high consistency between local and global results. However, in the pedestal region, the steep pressure gradient broadens $Δ_c$, driving quantitative deviations when $Δ_c$ becomes comparable to the plasma pressure gradient scale length. For high-$n$ MTMs, $ Δ_c $ can exceed the distance between adjacent mode rational surfaces. The resulted overlapping of current layers enhances the toroidal mode coupling effect, accounting for the substantial discrepancies observed between local and global simulations.
