Generation and amplification of magnetic islands by drift interchange turbulence.
Generation and amplification of magnetic islands by drift interchange turbulence.
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DOI：
10.1103/physrevlett.107.095003
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发表时间：
2011-08
影响因子：
8.6
通讯作者：
M. Muraglia;O. Agullo;S. Benkadda;M. Yagi;X. Garbet;A. Sen
中科院分区：
文献类型：
--
作者：
M. Muraglia;O. Agullo;S. Benkadda;M. Yagi;X. Garbet;A. Sen
利用二维MHD数值模拟方法研究了小尺度交换湍流下线性稳定和不稳定撕裂模的多尺度非线性动力学。对于一个稳定的撕裂模式，增长最快的小尺度交换模式的非线性跳动驱动一个磁岛与增强的增长速度到饱和的大小，这是成比例的湍流产生的异常扩散。对于一个线性不稳定撕裂模式的岛屿饱和尺寸的比例成反比的线性撕裂增长率的四分之一的权力，根据弱湍流理论的预测。湍流也被认为是引入显着的修改，在周围的磁岛的流动模式。
We investigate the multiscale nonlinear dynamics of a linearly stable or unstable tearing mode with small-scale interchange turbulence using 2D MHD numerical simulations. For a stable tearing mode, the nonlinear beating of the fastest growing small-scale interchange modes drives a magnetic island with an enhanced growth rate to a saturated size that is proportional to the turbulence generated anomalous diffusion. For a linearly unstable tearing mode the island saturation size scales inversely as one-fourth power of the linear tearing growth rate in accordance with weak turbulence theory predictions. Turbulence is also seen to introduce significant modifications in the flow patterns surrounding the magnetic island.