Physics design of the national high-power advanced torus experiment

The physics design described above provides an existence proof of a device capable of pursuing a mission of studying the integration of a fusion-relevant plasma-material interface with stable steady-state high-performance plasma operation. The design demonstrates flexibility to test multiple divertors, first-wall components, plasma exhaust configurations, boundary shapes, and plasma current profiles. Future design activities will focus on the design implications of high-temperature walls, the choice of wall material, trace-tritium for retention studies, and liquid metals for high heat flux and particle control. The avoidance of transient heat-loads to the divertor and first wall is essential in Demo. Thus, coil designs for ELM suppression and resistive wall mode control will also be pursued in addition to disruption avoidance and mitigation techniques. With these integrated design features, the NHTX device would advance the science and technology necessary to accelerate a nuclear component testing mission at reduced risk.