Gyrokinetic Simulations in General Geometry and Applications to Collisional Damping of Zonal Flows
Authors: Z. Lin, T.S. Hahm, W.W. Lee, W.M. Tang, and R.B. White
Date of PPPL Report: February 2000
Published in: Phys. Plasmas 7 (May 2000) 1857-1862.
A fully three-dimensional gyrokinetic particle code using magnetic coordinates for general geometry has been developed and applied to the investigation of zonal flows dynamics in toroidal ion-temperature-gradient turbulence. Full torus simulation results support the important conclusion that turbulence-driven zonal flows significantly reduce the turbulent transport. Linear collisionless simulations for damping of an initial poloidal flow perturbation exhibit an asymptotic residual flow. The collisional damping of this residual causes the dependence of ion thermal transport on the ion-ion collision frequency even in regimes where the instabilities are collisionless.