Highlights of Recent DIII-D Experimental Results

Recent DIII-D experiments contributed to the ITER physics basis and to physics

understanding for future devices. Pressure broadening for AE control from co-/counter-Ip

steerable off-axis NBI, and injection of high harmonic FW from a helicon antenna were

demonstrated A high beta-p optimized-core scenario with an ITB was coupled to a

detached divertor, and a Super H-mode optimized-pedestal scenario was coupled to a

radiative divertor. Pedestal pressure evolution, and electron vs. ion heat flux, measuring

both ne and delta-B fluctuations, identify pedestal turbulence during ELM recovery. New

non-linear 2-fluid modeling confirms RMP ELM suppression requires small pedestal top

ExB velocity. High current RE beams show excitation of current-driven kink instabilities

that terminate the beam on an Alfvenic time-scale. Real-time stability proximity control

and neural-net-based VDE growth-rate calculations are shown to prevent VDEs. Single

and multiple neon SPI particle assimilation rates and CQ densities are shown to be

predictable from 0-D models. ExB effects are important for divertor W transport. Measured

divertor impurity densities validate 2D models. Negative triangularity plasmas show

reduced H-mode power degradation and an L-mode ELM-free edge.