Achievement of reactor-relevantβin low-qdivertor discharges in the doublet III-D tokamak

A volume average toroidal {β} of 6.2% has been obtained with 10 MW of hydrogen neutral beam injection into deuterium divertor discharges in DIII-D. High-{β} discharges were maintained quiescently for many energy confinement times in elongated, {κ}=2, divertor discharges where the safety factor at the 95% flux surface was near 2. The maximum {β} calculated to be stable against ideal kinks and ideal ballooning modes is 8.5%--9.5%, confirming that these I/aB{}2.5 MA/m T discharges are some distance below the stability limit.