Thermal management of tungsten leading edges in DIII-D

The DiMES materials probe exposed tungsten blocks with 0.3 and 1 mm high leading edges to DIII-D He plasmas in 2015 and 2016 viewed with high resolution IRTV. The 1-mm edge may have reached >3000 °C in a 3-s shot with a (parallel) heat load of ∼80 MW/m2 and ∼8.6 MW/m2 on the surface based on modeling. The experiments support ITER. Leading edges were also a concern in the DIII-D Metal Tile Experiment in 2016. Two toroidal arrays of divertor tiles had W-coated molybdenum inserts 50 mm wide radially. This paper presents data and thermal analyses.