L-H Transition Studies on DIII-D to Determine \hbox{H-mode} Access for Operational Scenarios in ITER

A comprehensive set of L-H transition experiments has recently been performed on DIII-D to determine the requirements for access to H-mode plasmas in ITER's first (non-nuclear) operational phase with H and He plasmas, and second (activated) operational phase with D plasmas. The results from these experiments have revealed that the H-mode power threshold, $P_{\rm TH}$: (a) increases with the applied torque for all 3 main ion species (H, He, D); (b) increases with the application of the I-coil current, which is normally used to induce $n=3$ resonant magnetic perturbations required for edge localized mode (ELM) suppression; (c) can be significantly reduced by changing the plasma geometry; (d) exhibits a weak dependence on the edge electron and ion temperatures, but shows a strong dependence on the edge toroidal rotation; and (e) is not significantly affected by the application of magnetic error fields expected from test blanket module assemblies in ITER.