Collisionality and temperature dependence of the edge main-ion co-current rotation profile feature on DIII-D
POSTER
Abstract
A new edge main-ion (D$^{\mathrm{+}})$ CER system and upgraded edge impurity system are revealing clear differences between the main-ion and dominant impurity (C$^{\mathrm{6+}})$ toroidal rotation from the pedestal top to the scrape off layer on DIII-D with implications for intrinsic rotation studies. A peaked co-current edge toroidal rotation is observed for the main ion species near the outboard midplane separatrix with values up to 140km/s for low collisionality QH modes. In lower power (P$_{\mathrm{NBI}}=$0.8MW) H-modes the edge rotation is still present but reduced to \textasciitilde 50km/s. D$^{\mathrm{+}}$ and C$^{\mathrm{6+}}$ toroidal rotation differences are presented for a variety of scenarios covering a significant range of edge collisionality and T$_{\mathrm{i}}$. Observations are compared with predictions from several models including collisionless ion orbit loss calculations and more complete modeling using the XGC0 code, which also predicts 140km/s edge rotation for low collisionality QH mode cases.
*Work supported by the U.S. DOE under DE-AC02-09CH11466, No. DE-FC02-04ER54698, and DE-FC02-95ER54309.