The local magnetic field scaling of gyrokinetic turbulence and its impact on tokamak transport

Gyrokinetic turbulence simulations with the CGYRO [2] and GENE [3] codes were performed in order to investigate the dependence of the turbulent transport on magnetic flux surface geometry. The 3-D saturated electric potential fluctuation intensity spectrum and the overall changes in the energy fluxes were examined to determine the dependence on the elongation and Shafranov shift of flux surfaces. A new saturation model, used in a quasi-linear evaluation of the fluxes, is able to reproduce the gyrokinetic fluxes well [4]. The verification and calibration of this model with a large database of CGYRO turbulence simulations is presented in Ref. [5].