Integrated Scenario Modeling for Advanced Scenario Development in DIII-D

Integrated predictive simulations are carried out to guide design of Advanced Tokamak (AT) experiments with upgraded DIII-D hardware. Recent advances in the theory-based modeling include improved transport models for particle and momentum and integration with realistic feedback control algorithms as used in the DIII-D experiments. The modeling tools are validated successfully against recent AT experiments: (i)~sustained ($\sim $2 s) operation with $\beta _{N}$~$\approx $~4 (50{\%} above the no-wall stability limit) with internal transport barrier using toroidal field ramp, and (ii) fully noninductive operation [in-principle steady state (SS)] with $\beta _{N}$~$\approx $~3.5. Present simulation efforts focus on optimizing SS conditions at higher $\beta $ by utilizing the increased electron cyclotron and fast wave power in a pumped double-null configuration, indicating that SS can be achieved with $\beta _{N}$~$\ge $~4 for longer than a current relaxation time using the upgraded hardware planned for DIII-D.