Physics exploration of scenarios towards breakeven and burning plasmas in the SPARC tokamak*

This talk will cover modeling and predictions of SPARC scenarios beyond the previously described, high fusion gain primary reference discharge (PRD). Most physics studies of SPARC scenarios to inform the engineering design of the machine have been focused on the PRD, as it is often the plasma scenario with the most demanding requirements on tokamak systems. The PRD scenario is predicted both empirically and with physics-based models to produce over 100MW of fusion power with a gain of Q=9-11 [1]. However, while tokamak operators and scientists build expertise towards this landmark discharge, a number of other plasma regimes will necessarily be explored and thus it becomes increasingly important to understand the parameter space that SPARC is predicted to operate at. This work will review the PRD and modeling assumptions used, and will present predictions and simulations of scenarios expected to be accessed in the path to breakeven (Q>1), SPARC’s core mission (Q>2), and the burning-plasma regime (Q>5). Parameters such as confinement regime, plasma shaping, ICRF input power, minority scheme, and average density will be examined to inform SPARC’s research program and determine the safest and fastest path towards net fusion energy.

[1] P. Rodriguez-Fernandez, J.Plasma Phys 86(5), 2020