Interplay between central ECRH and saturated (m,n)  =  (1, 1) MHD activity in mitigating tungsten accumulation at ASDEX Upgrade

A new method for the determination of 2D intrinsic tungsten density profiles in the presence of saturated MHD instabilities at ASDEX Upgrade is presented.For the first time the full decoupling of the impurity density from electron density and temperature contributions to experimental 2D SXR tomographic reconstructions in the presence of MHD can be performed.The analysis relies on a combination of SXR tomography with the reconstruction of 2D electron temperature profiles through harmonic decomposition of the 1D ECE electron temperature.The method is applicable to any saturated magnetic perturbation as long as the poloidal and toroidal mode numbers m and n are known, and if the concentration of the intrinsic tungsten is high enough to dominate the SXR signals.This method may help better understand the mitigation of tungsten accumulation by central ECRH which typically occurs in the presence of saturated (m, n) = (1, 1) MHD activity.The analysis of the evolution of the intrinsic tungsten density in a typical ASDEX Upgrade discharge with central ECRH and saturated (1, 1) modes is presented.