Overview of the in-vessel diagnostics systems on the SPARC tokamak*

Numerous plasma diagnostics will be installed on SPARC for real-time plasma control and the investigation of high-field tokamak physics to derisk the design of ARC. A subset of SPARC diagnostics are “in-vessel” sensors that are mounted to the vacuum vessel, port plugs and plasma facing components. A suite of neutral gas diagnostics, magnetic sensors, bolometers, Langmuir probes, thermocouples and displacement and strain sensors will be utilized for plasma control, optimization of wall conditioning, controlling power balance, preventing damage to components from high heat loads and plasma disruptions and investigating advanced divertor configurations. Modular diagnostic feedthroughs are designed to carry electrical and optical signals from these sensors through the primary vacuum boundary to diagnostics labs. Significant prototyping work has been completed in a 60 degree mock-up vacuum vessel to derisk in-vessel diagnostic assembly, and all systems are transitioning from final design to procurement. This summary presents the current status of the in-vessel diagnostic systems design and the path forward to prepare for assembly and commissioning as the systems go through final design and push towards the pre-assembly stage.

This work was supported by Commonwealth Fusion Systems.