Comprehensive experimental turbulence measurements for scale-resolved multichannel gyrokinetic code validation
Résumé
Turbulence is the main driver of heat and particle transport which deteriorates the performance of fusion plasmas. To design turbulence optimised devices, simulation codes need to be validated by experiments. Validation work has already been done for a single or a small number of turbulence observables.
A comprehensive set of experimental turbulence data is measured on ASDEX Upgrade
for two different plasma scenarios where the electron gradient length is changed by means
of ECRH. It includes wavenumber spectra, density and temperature fluctuation amplitudes
and radial correlation lengths, the poloidal dependence of the velocity perpendicular to the
magnetic field as well as the cross-phase between density and temperature fluctuations.
These quantities are measured by Doppler reflectometers in both X-mode and O-mode polarization
and an electron cyclotron emission radiometer. They are compared to gyrokinetic
turbulence simulations from the GENE code. For this purpose synthetic diagnostic modeling
is applied to account for diagnostic effects on measurements.
The work shows the encouraging example of code validation where a remarkable number
of measured physics quantities is successfully reproduced by the code. We highlight
the simultaneous agreement between experiment and simulation of all investigated turbulence
quantities. This study provides a sound scientific justification for using codes such as
GENE in the design of future fusion reactors.
Domaines
Physique [physics]
Origine : Fichiers produits par l'(les) auteur(s)