In absence of external torque, plasma rotation in tokamaks results from a balance between collisional magnetic braking and turbulent drive. The outcome of this competition and cooperation is essential to determine the plasma flow. A reduced model, supported by gyrokinetic simulations, is first used to explain and quantify the competition only. The ripple amplitude above which magnetic drag overcomes turbulent viscosity is obtained. The synergetic impact of ripple on the turbulent toroidal Reynolds stress is explored. Simulations show that the main effect comes from an enhancement of the radial electric field shear by the ripple, which in turn impacts the residual stress.

中文翻译：

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湍动量驱动与磁制动的协同作用

在没有外部扭矩的情况下，托卡马克中的等离子体旋转是由碰撞磁制动和湍流驱动之间的平衡造成的。这种竞争和合作的结果对于确定血浆流量至关重要。由陀螺动力学模拟支持的简化模型首先仅用于解释和量化竞争。获得了磁阻力克服湍流粘度的波纹幅度。探讨了波纹对湍流环形雷诺应力的协同影响。模拟表明，主要影响来自纹波对径向电场剪切的增强，这反过来又会影响残余应力。