Damping of toroidal rotation by anomalous ion viscosity

The quasi-linear drift turbulence theory of toroidal momentum damping in axisymmetric plasmas for the banana collisionality regime is studied. The toroidal angular velocity is considered as a flux function, with viscosity between adjacent flux surfaces giving rise to damping of the toroidal rotation. Anomalous viscosity is shown to be due to resonance interaction of passing ions with drift wave fluctuations. By employing a spectrum of Pearlstein-Berk structure modes satisfying the symmetry of ballooning representation and using appropriate action angle variables for the description of particle motion the viscosity is evaluated as η ∼ (ρs/LN)(cT/eB). (author). 12 refs