Interpretation of Diffusive and Nondiffusive Transport in Tokamak Edge Pedestal Measurements

A formalism, based on particle, momentum, and energy balance constraints, for the interpretation of diffusive and nondiffusive transport from plasma edge measurements is presented and applied to interpret transport differences between low-mode and high-mode DIII-D [J. Luxon, Nucl. Fusion, Vol. 42, p. 614 (2002)] plasmas. The experimental values of basic transport properties (thermal diffusivities and momentum transport frequencies) inferred for H-mode and L-mode are compared with each other and with "classical" predictions. Once the basic transport mechanisms are ascertained by such comparison of theoretical predictions with experimental inference, the presented formalism will provide a first-principles predictive model for density, temperature, velocity, and pressure profiles in the edge pedestal.