Role of nonlinear toroidal coupling in electron temperature gradient turbulence
Role of nonlinear toroidal coupling in electron temperature gradient turbulence
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DOI：
10.1063/1.1894766
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发表时间：
2005-05
影响因子：
2.2
通讯作者：
Zhihong Lin;Liu Chen;F. Zonca
中科院分区：
文献类型：
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作者：
Zhihong Lin;Liu Chen;F. Zonca
全球回旋粒子模拟和非线性回旋理论发现，电子温度梯度（ETG）不稳定性饱和通过非线性环形耦合，这是一个非局域相互作用的波矢量空间中，转移能量从不稳定模式的阻尼模式优先与较低的环形模式数。静电ETG湍流主要由非线性产生的径向流光。流光的长度与设备的尺寸成比例，这是长于模式合理的表面和电子径向偏移之间的距离。饱和时的波动强度和输运水平与流光长度无关，并且比混合长度估计值小得多。
Global gyrokinetic particle simulation and nonlinear gyrokinetic theory find that electron temperature gradient (ETG) instability saturates via nonlinear toroidal coupling, which is a nonlocal interaction in the wave vector space that transfers energy successively from unstable modes to damped modes preferentially with lower toroidal mode numbers. The electrostatic ETG turbulence is dominated by nonlinearly generated radial streamers. The length of the streamers scales with the device size, which is longer than the distance between mode rational surfaces and electron radial excursions. Both fluctuation intensity and transport level at saturation are independent of the streamer length, and are much smaller than the mixing length estimates.