Progress on first-principles turbulence simulations for realistic tokamak parameters

We previously reported the results of the most complete three-dimensional non-linear gyrokinetic-δ f-ion, adiabatic-electron simulations of ITG turbulence in TFTR to date. While the transport rates were consistent with experiment for the inner portion of the profile, it was found that for some TFTR L-mode discharges a significant portion of the ion-temperature profile (r/a > 0.6) could not be accounted for by the simulated transport rates. Here, we report three new developments that represent greater realism in the physics than previous kinetic models. (A) The simulation model has been extended to general axisymmetric geometry and interfaced to use reconstructed experimental equilibria from DIII-D. Comparisons will be made between the simulation results and experiment will be presented for DIII-D reversed- magnetic-shear discharges of current interest. (B) We have developed a new bounce-averaged drift-kinetic nonlinear-δf electron model. We will investigate whether this addition results in improved agreement with in the simulated ion-thermal transport rates with TFTR L-mode data. (C) A new massively parallel version of our code enables us to access sufficient computational resources to address for the first time with a first-principles simulation whether toroidal ITG turbulent transport has Bohm or gyroBohm scaling for realistic tokamak parameters. The results of this investigation will be presented