1 TH / P 4 - 17 Edge Turbulence , Blob Generation , and Interaction with Sheared Flows *

A program of 2D simulations of edge turbulence and blob generation using the Lodestar SOLT code is described. Issues studied include the transport of particles and poloidal momentum in the edge and SOL, the processes by which momentum transport drives sheared poloidal flow layers in the edge plasma, the nonlinear turbulence saturation mechanisms producing the blobs, and the interaction of blob generation with sheared flows. If the sheared flows are sufficiently strong, they can stabilize the underlying instability and saturate the turbulence. If the flows are weak, the saturation occurs by turbulent modification of the density profile (plateau formation or wave-breaking). A new synthetic gas-puff-imaging (GPI) diagnostic in the code has been used to compare the simulations with GPI data for the NSTX experiment. Statistics for the turbulent fluctuations and the blobs are compared between simulations and data. The conditions for obtaining qualitative agreement for one Lmode shot are described.