Progress in GYRO Validation Studies of DIII-D \mbox{H-mode} Plasmas

The need for a validated predictive capability of turbulent transport in ITER is now widely recognized. However, to date most validation studies of nonlinear codes such as GYRO have focused upon low power L-mode discharges, which have significant differences in key dimensionless parameters such as $\beta$ and $\rho^* = \rho_s/a$ from more ITER-relevant H-mode discharges. In order to address this gap, the results of nonlinear GYRO simulations of a range of DIII-D H-mode discharges (including quiescent H-mode, hybrid, and steady state discharges) are presented. These H-mode studies focus upon three physics effects, motivated by key differences between L- and H-mode plasmas. The first is the linear and nonlinear effects of finite $\beta$ in plasmas where $\beta_N = \beta/(I/aB)$ varies from 1.5-2.5, 3-5 times higher than typical L-mode values. Second is the impact of nonlocality at typical DIII-D H-mode $\rho^*$ values, which in contrast to typical L-modes can be non-negligible. Third is the stabilizing effect of a significant density of energetic particles.