Design concepts for visible, UV and IR imaging and spectroscopy diagnostic systems for SPARC*

Imaging and spectroscopy in the visible, UV, and IR regions of the electromagnetic spectrum are two of SPARC's necessary, early campaign diagnostic systems. Even though imaging and spectroscopic systems rarely vary in design and function when used in different types of tokamaks, they face specific challenges when designed for SPARC. The design is mainly influenced by the environmental constraints, especially on the in-vessel collection optics (such as large disruption loads and neutron and plasma thermal heat fluxes), unique physical and enabling interfaces within the SPARC facility, and the anticipated mission-driven measurement requirements that these diagnostic systems must meet.

This contribution gives the most recent snapshot of the ongoing work to concretize the design of these two diagnostic systems. We show the concepts for light extraction, optical access, and transmission paths, which have been developed to prioritize the design's uniformity across multiple subsystems. Furthermore, we explore the requirements for back-end instrumentation and the possibilities for achieving them. Finally, we address the present and future prototyping required to retire the main risks associated with these two diagnostic systems for SPARC.