Pedestal Prediction and Stability Analysis in SPARC H-modes

Pedestal performance and stability in SPARC H-modes are investigated using a workflow employing the EPED and ELITE codes. EPED [Snyder PoP 2009] predictions show that the ratio of separatrix density to pedestal top density plays a critical role in determining whether the SPARC pedestal is limited by peeling or ballooning modes, significantly affecting the predicted pedestal pressure, while the separatrix temperature is not a significant factor. Linear MHD stability analysis is performed with ELITE [Snyder PoP 2002] based on the kinetic equilibria produced by VARYPED. A fixed boundary equilibrium calculation is used in VARYPED to reflect changes in density and temperature contributions to the pressure profile to investigate dominant pedestal mode characteristics. This workflow enables the exploration of more accurate equilibria than those assumed by EPED on pedestal stability for SPARC. Future extensions include integration with density pedestal prediction models based on particle transport. Collaborative work with a non-linear MHD code such as M3D-C1 is planned to investigate ELM physics.