Heat Flux Testing of Prototype NSTX-U Plasma Facing Components

The upgrade to the National Spherical Torus eXperiment (NSTX-U) doubles the neutral beam power and enables plasmas to be sustained for up to 5 seconds. The graphite plasma facing components (PFCs) have been re-designed to handle greater heat and energy fluxes than were seen in NSTX using a castellated design. These new PFCs were designed to be able to withstand uniform, perpendicular heat fluxes of up to 8 MW/m² for up to 5 seconds before reaching a surfaced averaged temperature limit of 1600 C. We present experimental testing of prototype, castellated graphite PFCs in an electron beam (EB) facility which provides temporally non-uniform heat fluxes on target. Due to the temporally non-uniform nature of the heat fluxes the EB facility provides, the thermal analysis used to design the prototype PFC tiles will be benchmarked against in-situIR thermography and calorimetric measurements with self-consistent boundary conditions to the prototype testing.