"Overview of the PPPL International Experimental Stellarator Collaboration Activity", Dr. David Gates, Princeton University

PPPL has initiated and strengthened collaborative experimental programs aimed at developing the required toolsets and scientific knowledge for advancing stel- larators as a viable fusion energy source. In particular, activities at LHD and W7-X, the two large superconducting helical confinement systems in the world, have been expanded. The focus at LHD has been on diagnostic development and data analysis, since the device is a mature research facility with more than 20MW of heating power available. High beta stability experiments, ion and elec- tron temperature measurements using a recently installed imaging x-ray crystal spectrometer, and 3D equilibrium reconstructions will be described. The focus on W7-X has been to develop hardware capabilities for divertor heat flux control, including plasma-facing components, error field correction coils, and power sup- plies. Progress on these and other activities will be presented.