The flux of parallel momentum by parallel shear flow driven instability is calculated with the self-consistent mode dispersion. The result indicates that the diffusive component has two characteristic terms: νD1 ～ ?x2/γ(0) and νD2 ～ ?x2 /(k∥2D∥) where ?x is the fluctuation radial velocity, γ(0) is the growth rate of the mode, k∥ is the parallel wave number, and D∥ is the electron diffusivity along the magnetic field. νD1 results when the parallel flow shear is above the threshold, while νD2 is important around the marginal state. Since typically νD1 ? νD2 ～ Dn, where Dn is the particle diffusivity, the Prandtl number (≡ ν/Dn) becomes large when parallel flow shear driven instability occurs. This feature may explain the experimental observation on the difference between profiles of density and toroidal flow in edge and SOL plasmas.
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机译：利用自洽模态色散计算平行剪切流驱动的不稳定性引起的平行动量通量。结果表明，扩散成分具有两个特征项：ν D 1 〜？ x 2 /γ（0）和ν D 2 〜？ x 2 /（k ∥ 2 D ∥）其中？ x 是波动径向速度，γ（0）是该模式的增长率，k ∥是平行波数，D ∥是沿磁场的电子扩散率。当平行流切变高于阈值时，结果ν D 1 ，而ν D 2 在边界附近很重要。边缘状态。因为通常是ν D 1 ？ ν D 2 〜D n ，其中D n 是粒子扩散率，普朗特数（≡ν/当发生平行流剪切驱动的不稳定性时，D n ）变大。此功能可以解释有关边缘和SOL等离子体中密度和环形流动轮廓之间差异的实验观察。
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