Validative and Predictive Extended-Magnetohydrodynamic Modeling of Disruption Mitigation

Future tokamaks will require disruption mitigation systems to prevent machine damage. Verified, predictive models are needed to project these systems to future devices. We present results for validative and predictive modeling of shattered-pellet injection (SPI) using the M3D-C1 extended-MHD code. We compare modeling results to several realistic scenarios on the KSTAR tokamak, including single versus dual-symmetric injection with neon-doped pellets as well as dual, time-staggered injection with a pure-deuterium pellet followed by a neon-doped pellet. Initial comparisons to density and radiation measurements have shown discrepancies in both time scale and magnitude. We explore the effects of the localization of the plasma source and of equilibrium plasma rotation on these results. M3D-C1 is also being used to predict the behavior of SPI in ITER 15-MA plasmas, considering both single and dual injection. We present progress in these simulations and ongoing efforts to overcome the numerical challenges caused by the high pressures and currents in ITER plasmas. Finally, we explore an upgrade of the impurity model within M3D-C1 to make use of ADAS, both within the coronal limit and the full collisional-radiative regime.