Evaluation of Particle Pinch and Diffusion Coefficients in the Edge Pedestal of DIII-D H-mode Discharges

Momentum balance requires that the radial particle flux satisfy a pinch-diffusion relationship. The pinch can be evaluated in terms of measurable quantities (rotation velocities, $E_r$, etc.) by the use of momentum and particle balance [1,2], the radial particle flux can be determined by momentum balance, and then the diffusion coefficient can be evaluated from the pinch diffusion relation using the measured density gradient. Applications to several DIII-D H-mode plasmas are presented. \vskip6pt \noindent [1] W.M. Stacey, Contr. Plasma Phys. {\bf 48}, 94 (2008). \break \noindent [2] W.M. Stacey and R.J. Groebner, Phys. Plasmas {\bf 15}, 012503 (2008).