Nonlinear parallel momentum transport in strong electrostatic turbulence

Nonlinear parallel momentum transport in strong electrostatic turbulence

Poloidal rotation driven by nonlinear momentum transport in strong electrostatic turbulence

Virtually, all existing theoretical works on turbulent poloidal momentum transport are based on quasilinear theory. Nonlinear poloidal momentum flux 〈ṽrñṽθ〉 is universally neglected. However, in the strong turbulence regime where relative fluctuation amplitude is no longer small, quasilinear theory is invalid. This is true at the all-important plasma edge. In this work, nonlinear poloidal momen...

Transport of parallel momentum by drift-Alfvén turbulence

An electromagnetic gyrokinetic formulation is utilized to calculate the turbulent radial flux of parallel momentum for a strongly magnetized plasma in the large aspect ratio limit. For low-! plasmas, excluding regions of steep density gradients, the level of momentum transport induced by microturbulence is found to be well described within the electrostatic approximation. However, near regions ...

Transport of parallel momentum by collisionless drift wave turbulence

This paper presents a novel, unified approach to the theory of turbulent transport of parallel momentum by collisionless drift waves. The physics of resonant and nonresonant off-diagonal contributions to the momentum flux is emphasized, and collisionless momentum exchange between waves and particles is accounted for. Two related momentum conservation theorems are derived. These relate the reson...

Nonlinear flow generation by electrostatic turbulence in tokamaks

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient ITG modes and trapped electron modes TEMs . In collisionless TEM CTEM turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetr...