平行速度剪切驱动湍流引起的粒子输运

通过离子温度梯度及平行速度剪切的准线性湍流理论，得到了由杂质离子及抵频E×B湍流所驱动的径向离子流及相应的输运系数．理论分析表明，主要离子和杂质离子的径向离子流具有相反的方向，并随着平衡流速剪切以及杂质离子的密度梯度的变化而改变．增强平行速度剪切对主要离子的约束可产生有利影响 关键词：

PARTICLE TRANSPORT FROM TURBULENCE DRIVEN BY-PARALLEL VELOCITY SHEAR

The turbulence driven by ion temperature gradient,mass flow shear,parallel to the magnetic field,and the impurity ion density gradient in plasmas with multiple ion species is studied in a sheared slab magnetic configuration.The particle diffusion induced by the turbulence is obtained with quasi-linear fluid theory.The possible inward ‘pinch' of the majority ions and the inward flow of the impurity ions,depending on plasma parameters,are both calculated,and the corresponding diffusion coefficients are given.It is shown that the increase of parallel velocity shear may have benificial effects on plasma confinement.The correlations with Tokamak experimental observations are discussed.