Drift-wave turbulence and zonal flow generation.
Drift-wave turbulence and zonal flow generation.
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漂移波湍流和纬向流的产生。
DOI：
10.1103/physreve.68.046409
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Balescu
中科院分区：
文献类型：
--
作者：
R. Balescu
基于波刘维尔方程分析了等离子体中的漂移波湍流，描述了以位置 x 和波矢量 k 为特征的波包（准粒子）分布函数的演化。利用非平衡统计力学的方法，对该函数的系综平均部分导出了一个闭合动力学方程。它具有非马尔可夫平流扩散方程的形式，描述 x 和 k 空间中的耦合扩散过程。扩散系数的一般形式是根据拉格朗日速度相关性获得的。后者是在去相关轨迹近似中计算的，这是最近开发的一种方法，用于精确测量崎岖静电势中粒子的重要捕获现象。对各个去相关轨迹的分析提供了径向方向上漂移波结构的破碎以及极向方向上被识别为纬向流的长波长结构的生成的说明。
Drift-wave turbulence in a plasma is analyzed on the basis of the wave Liouville equation, describing the evolution of the distribution function of wave packets (quasiparticles) characterized by position x and wave vector k. A closed kinetic equation is derived for the ensemble-averaged part of this function by the methods of nonequilibrium statistical mechanics. It has the form of a non-Markovian advection-diffusion equation describing coupled diffusion processes in x and k spaces. General forms of the diffusion coefficients are obtained in terms of Lagrangian velocity correlations. The latter are calculated in the decorrelation trajectory approximation, a method recently developed for an accurate measure of the important trapping phenomena of particles in the rugged electrostatic potential. The analysis of individual decorrelation trajectories provides an illustration of the fragmentation of drift-wave structures in the radial direction and the generation of long-wavelength structures in the poloidal direction that are identified as zonal flows.