SPARC as a Path to ARC and Commercial Fusion Power*

This talk describes the current concept for the ARC pilot fusion power plant, compares parameters in various SPARC plasmas to anticipated ARC plasma parameters, and lays out the timeline in which SPARC plans to achieve milestones as handoffs to ARC design.  SPARC is being designed to achieve Q > 2 in order to demonstrate net energy production in a fusion device, and given nominal physics assumptions will have the capability of exploring regimes with Q ≈ 11 [A. J. Creely et al., J. Plasma Phys. 86 (5), 865860502 (2020)].  While these results will be an achievement in their own right, the true aim of SPARC is to validate the physics and technology necessary to build a commercial fusion power plant, currently embodied in the ARC design.  In addition to demonstrating high gain plasmas that are non-dimensionally similar to ARC plasmas, SPARC will also compare conventional and advanced divertor configurations at relevant heat and particles fluxes to inform ARC design.  SPARC operations will also inform the plasma control and diagnostics for ARC.  A rapid ramp up in SPARC capabilities enables the design and operation of ARC on a time frame consistent with combatting climate change and consistent with the goals laid out in recent FESAC and NASEM reports.