ISBN:  Unavailable

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Page count: 10

Results are presented from the 3D electromagnetic turbulence code BOUT, the 2D transport code UEDGE, and theoretical analysis of boundary turbulence and transport in a real divertor-plasma geometry and its relationship to the density limit. Key results include: (1) a transition of the boundary turbulence from resistive X-point to resistive-ballooning as a critical plasma density is exceeded; (2) formation of an X-point MARFE in 2D UEDGE transport simulations for increasing outboard radial transport as found by BOUT for increasing density; (3) formation of a density pedestal due to neutral fueling; (4)identification of convective transport by localized plasma 'blobs' in the SOL at high density and decorrelation of turbulence between the midplane and the divertor leg due to strong X-point magnetic shear; (5) a new divertor-leg instability driven by a radial tilt of the divertor plate.