Overview of Recent DIII-D Experimental Results*

Recent DIII-D experiments contributed to the ITER physics basis and to physics understanding for extrapolation to future devices. RMP ELM suppression and QH-mode operation advance toward ITER rotation and shape. GPEC multi-modal plasma response predictions were extended and validated for MHD damping rates and NTV torque control. Multiple locked islands are essential for deterioration of thermal confinement preceding thermal quench. Machine Learning algorithms predict disruptions correctly >90% of the time with <5% false positives. P_L-H found to have previously unidentified dependence on Ip or q95 at mid-density (ne~3e19 m-3). Detachment found at 20–30% lower ne,ped in a closed divertor, due to decreased pedestal fueling and increased SOL dissipation, both from increased neutral trapping in the divertor. Fluid codes factor of 3 under-prediction of radiating volume may contribute to divertor radiation shortfall at detachment. Data shows more than 10x reduction in erosion with slight positive voltage biasing due to reduced incident energy and ion flux. Tungsten sourcing during ELMs by D and low-Z impurities consistent with new ‘free-streaming’ model predictions of scaling with ELM deposited energy density