Dynamics of Nonlinear Coupling between Electron-Temperature-Gradient Mode and Drift-Wave Mode in Linear Magnetized Plasmas
Dynamics of Nonlinear Coupling between Electron-Temperature-Gradient Mode and Drift-Wave Mode in Linear Magnetized Plasmas
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DOI：
10.1103/physrevlett.111.115001
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发表时间：
2013-09-10
影响因子：
8.6
通讯作者：
Hatakeyama, Rikizo
中科院分区：
文献类型：
--
作者：
Moon, Chanho;Kaneko, Toshiro;Hatakeyama, Rikizo
垂直于磁力线的电子温度梯度（ETG）激发了高频（0.4 MHz）波动，这与ETG模式一致。当ETG模式的波动幅度超过一定阈值时，模式逐渐饱和，原本由漂移波引起的低频（类似于7 kHz）波动增强，对应于ETG模式的饱和。此外，当ETG强度超过阈值时，ETG模式与漂移波模式之间的非线性耦合，即双相干性开始增强，这种耦合与ETG模式的饱和同时发生。因此，可以确定ETG模式通过高频（类似MHz）和低频（类似kHz）波动之间的多尺度非线性相互作用刺激漂移波模式，最终导致ETG模式能量转移到漂移波模式。
A high-frequency (similar to 0.4 MHz) fluctuation is excited by an electron temperature gradient (ETG) perpendicular to magnetic field lines, which is consistent with an ETG mode. When the fluctuation amplitude of the ETG mode exceeds a certain threshold, the mode gradually becomes saturated and a low-frequency (similar to 7 kHz) fluctuation which is originally caused by a drift wave is enhanced, corresponding to the saturation of the ETG mode. In addition, a nonlinear coupling, specifically, the bicoherence between the ETG mode and the drift wave mode, begins to increase when the ETG strength exceeds the threshold, which simultaneously occurs with the saturation of the ETG mode. Thus, it was determined that the ETG mode stimulates the drift wave mode excitement via multiscale nonlinear interaction between the high-frequency (similar to MHz) and low-frequency (similar to kHz) fluctuations, which ultimately causes ETG mode energy to be transferred to the drift wave mode.