Development of Synthetic Diagnostics for NSTX-U Resistive Bolometry*

Accurate assessment of power balance in fusion devices, including NSTX-U, requires precise knowledge of the radiated power emitted by the core and edge plasma. Measurements of radiated power emission can be analyzed in conjunction with other diagnostics such as IR thermography to assess the discharge power balance. A resistive bolometry system has been proposed for use in NSTX-U for core and divertor radiated power measurements. The aim of the proposed divertor bolometer system is to characterize plasma emission in the vicinity of the X-point region and divertor strike points through the use of tomographic inversions from two crossing views. A consideration for bolometer design is to ensure that each of the foils has minimal overlap to avoid overestimating the plasma power output. We have established an NSTX-U bolometer base design and begun work on the synthetic diagnostics for the bolometer for both the midplane and lower divertor locations. This presentation will describe our current activities using Cherab to simulate the bolometer cameras and to optimize these systems to ensure adequate spatial resolution for accurate recreation of high spatial gradient emission patterns.