论文标题
带有磁岛链的剪切alfvén连续体在Tokamak等离子体中
The shear Alfvén continuum with a magnetic island chain in tokamak plasmas
论文作者
论文摘要
使用理想的磁性水力学（MHD）理论研究了带有单个岛链的Tokamak的剪切Alfvén连续谱。我们已经考虑了环形的几何形状和环形模式与该岛被认为是高度形状的恒星。岛内各种新的频率差距都在岛内开放，因为其不对称性既有性质又是旋转的，例如镜子诱导的alfvéneigenmode（MAE）间隙以及螺旋性诱导的alfvéneigenmode（hae）间隙。我们已经表明，MAE间隙充当外形环形Alfvéneigenmode（TAE）缝隙进入该岛的延续。但是，随着岛屿的发展，泰泰/毛的差距越来越狭窄，只剩下一半的原始宽度，中等岛的大小高达小半径的3.2％。此外，在MAE间隙下方的连续模式的二维征函数现在在岛上的长轴周围具有高度的局部结构，与通常的振动性全球解决方案相反，没有或低或低的环形脱色水平 - 一种持续光谱的表明，连续光谱已成为离散和密集。这些结果对位于间隙中的全局TAE的频率，模式结构和连续阻尼有影响。
The shear Alfvén continuum spectrum is studied for a tokamak with a single island chain using the ideal Magnetohydrodynamics (MHD) theory. We have taken into account the toroidal geometry and toroidal mode coupling with the island considered as a highly-shaped stellarator. Various new frequency gaps open up inside the island due to its asymmetry both poloidally and toroidally, such as the Mirror-induced Alfvén Eigenmode (MAE) gap and the Helicity-induced Alfvén Eigenmode (HAE) gap. We have shown that the MAE gap acts as the continuation of the outside Toroidal Alfvén Eigenmode (TAE) gap into the island. However, the combined TAE/MAE gap is getting narrower as the island grows, leaving only half of its original width with a moderate island size as much as 3.2% of the minor radius. In addition, the two-dimensional eigenfunction of the continuum mode on the lower tip of the MAE gap now has highly localised structures around the island's long axis, contrary to the usual oscillatory global solutions found with no or a low level of toroidal asymmetry - an indication of the continuous spectrum becoming discrete and dense. These results have implications for the frequency, mode structure and continuum damping of global TAEs residing in the gap.
