Turbulence studies in tokamak boundary plasmas with realistic divertor geometry

Results are presented from the 3-D non-local electromagnetic turbulence cod e BOUT and the linearized shooting code BAL for studies of turbulence in to kamak boundary plasmas and its relationship to the GH transition, in a real istic divertor plasma geometry. The key results include: (1) the identifica tion of the dominant resistive X point mode in divertor geometry; (2) turbu lence suppression in the L-H transition by shear in the E x B drift velocit y, ion diamagnetism and finite polarization; (3) the fact that calculated v alues of the thermal diffusivities such as Xi are comparable to those infer red from the experimentally measured plasma density and temperature profile s. On the basis of simulation results, a parameterization of the transport is given that includes the dependence on the relevant physical parameters.