Nonlinear toroidal mode coupling: a new paradigm for drift wave turbulence in toroidal plasmas
Nonlinear toroidal mode coupling: a new paradigm for drift wave turbulence in toroidal plasmas
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DOI：
10.1088/0741-3335/47/12b/s06
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发表时间：
2005-12
影响因子：
2.2
通讯作者：
L. Chen;F. Zonca;Zhihong Lin
中科院分区：
文献类型：
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作者：
L. Chen;F. Zonca;Zhihong Lin
全球回旋粒子模拟和非线性回旋理论表明，电子温度梯度（ETG）的不稳定性饱和通过非线性环形耦合。在这种非线性相互作用中，波能量在不稳定的高环模数域级联向更稳定的低环模数域通过散射驱动的低模准模。在饱和过程中，几乎没有纬向流的产生，径向脉动包络线保持着扩展结构。非线性耦合过程严重依赖于环形的几何形状，因此，代表了一个新的范例的光谱级联漂移波湍流环形系统。
Global gyrokinetic particle simulations and nonlinear gyrokinetic theory indicate that electron temperature gradient (ETG) instability saturates via nonlinear toroidal coupling. In such nonlinear interactions, the wave energy at the unstable high toroidal-mode number domain cascades towards the more stable lower toroidal-mode number domain via scatterings off the driven low-mode number quasi-modes. During the saturation process, there is little zonal flow generation and the radial fluctuation envelopes maintain extended structures. The nonlinear coupling process depends critically on the toroidal geometry and, as such, represents a new paradigm for the spectral cascade of drift wave turbulence in toroidal systems.