Numerical computation of collisionless drift Alfven turbulence

An electromagnetic hybrid model of drift-kinetic electrons and cold ions in three-dimensional sheared slab geometry is constructed to treat collisionl ess drift Alfven turbulence in tokamak edge plasmas. The basic nonlinear eq uations are solved numerically using explicit finite-difference methods on a phase-space grid rather than an ensemble of "superparticles." Basic prope rties of the turbulent fluctuations such as amplitude and phase distributio ns, amplitude correlations, and energy spectra are investigated. The result ing turbulent particle transport by magnetic flutter is negligible compared to that by E X B convection. However, the intrinsic dynamics of the turbul ence remains electromagnetic due to the influence of kinetic shear Alfven w aves and magnetic flutter. Comparisons with a companion Landau-fluid model are more successful than in similar studies of ion temperature gradient tur bulence. (C) 1999 American Institute of Physics. [S1070-664X(99)02607-5].