Full torus Landau fluid calculations of ion temperature gradient-driven turbulence in cylindrical geometry

Abstract

Results of Landau fluid calculations of ion temperature gradient-driven turbulence in cylindrical geometry but which cover the whole plasma cross section are reported. A simple gyrofluid model is used which evolves in time equations for the ion density or vorticity, the parallel ion velocity, and the ion temperature where Landau damping is included through a linear closure relation. Adiabatic electrons and the electrostatic approximation are assumed to hold. Linear calculations indicate that the growth rates are significantly reduced in the presence of Landau damping. Nonlinear single helicity calculations serve to illustrate the spatial localization of the turbulence in the presence of Landau damping. Finally nonlinear multiple helicity calculations performed with three different values for the ratio of the central ion Larmor radius to the plasma minor radius denoted by ρ* exhibit a definite linear scaling of all the fluctuation characteristics, such as levels, scale sizes, quasilinear profile modifications, self-generated poloidal flows, and heat diffusivities, with ρ*. © 2000 American Institute of Physics.