Enhancements in the second generation DIII-D digital plasma control system

This paper will discuss alterations and enhancements of the real-time digital plasma control system (PCS) which were recently developed at DIII-D. These enhancements greatly increased the performance and scope of the control system after a successful upgrade from the previous VME-based version. A specific goal of these enhancements was to incorporate the charge exchange recombination spectrometry diagnostic for plasma rotation control. Enlargement of the PCS includes additional motional Stark effect channels for improved current profile control and a series of real-time data displays. Performance improvements include increased computing resources, multi-threaded parallel processing, and 11 μs cycle times for the resistive wall mode component feedback.