Upgrade and benchmark of quasi-linear transport model EDWM

Abstract

The verification of a new saturation rule applied to the quasi-linear fluid model EDWM (extended drift wave model) and the calibration of several other features are presented. As one of the computationally fastest first-principle-based core transport models, EDWM can include an arbitrary number of ions and charge states. This feature is especially important for experimental devices with plasma-facing components made of heavy elements, such as the upcoming ITER device. As a quasi-linear model, EDWM solves a linear dispersion relation to obtain the instabilities driving the turbulence and combines the linear description with an estimation of the saturation level of the electrostatic potential to determine the fluxes. A new saturation rule at the characteristic length combined with a spectral filter for the poloidal wavenumber dependency is developed. The shape of the filter has been fitted against the poloidal wavenumber dependency of the electrostatic potential from non-linear gyrokinetic simulations. Additionally, EDWM's collision frequency and safety factor dependencies, as well as the electron heat flux level, have been calibrated against gyrokinetic and gyrofluid results. Finally, the saturation level has been normalized against non-linear gyrokinetic simulations and later validated against experimental measured fluxes from 12 discharges at JET.