We show that linear collisionless processes do not damp poloidal flows driven by ion-temperature-gradient (ITG) turbulence. Since these flows play an important role in saturating the level of the turbulence, this level, as well as the transport caused by ITG modes, may be overestimated by gyrofluid simulations, which employ linear collisionless rotation damping.

• Received 27 August 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.724