Linear analysis of the double‐tearing mode
Linear analysis of the double‐tearing mode
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DOI：
10.1063/1.863151
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发表时间：
1980-07
影响因子：
4.6
通讯作者：
P. Pritchett;Y. C. Lee;J. Drake
中科院分区：
文献类型：
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作者：
P. Pritchett;Y. C. Lee;J. Drake
在磁流体力学的框架内研究了双撕裂模的线性行为。进行双空间尺度分析，其中在有理表面附近有效的电阻解与这些区域之外的理想解相结合，并用于推导模式的色散关系。如果有理曲面在x=±xs处的间距足够小[xs/a<（kya）−7/9 S −1/9]，则增长率被预测为S−1/3，并且模式的结构被证明与圆柱几何中m=1撕裂模式的结构基本相同。随着分离度的增加，模式会过渡到S−3/5尺度和标准撕裂模式的结构。这些预测通过磁流体动力学方程的直接数值解得到证实，并且S−1/3标度与常数近似的违反相关。讨论了双撕裂模可能的物理意义。
The linear behavior of the double‐tearing mode is investigated within the framework of magnetohydrodynamics. A two‐space‐scale analysis in which resistive solutions valid near the rational surfaces are joined to ideal solutions outside these regions is performed and used to derive the dispersion relation for the mode. If the separation of the rational surfaces at x=±xs is sufficiently small [xs/a<(kya)−7/9S−1/9], the growth rate is predicted to scale as S−1/3, and the structure of the mode proves to be essentially identical with that of the m=1 tearing mode in cylindrical geometry. With increasing separation, the mode makes a transition to the S−3/5 scaling and structure of the standard tearing mode. These predictions are confirmed by direct numerical solution of the magnetohydrodynamic equations, and the S−1/3 scaling is shown to be correlated with violations of the constant‐ψ approximation. Possible physical implications of the double‐tearing mode are discussed.