Impact of electron heating on a turbulent transport of middle and high-Z impurities in DIII-D tokamak

Central electron cyclotron heating (ECH) is an effective tool for preventing the accumulation of impurities in the plasma core. It is believed that impurities are removed by a combination of reduced neoclassical pinch and destabilization of turbulent modes. To clarify a role of turbulence, trace Al and W ions were introduced in DIII-D ELM-y H-mode discharges via new laser blow-off system. In these experiments, the balance of ECH and neutral beam injection (NBI) was varied during each shot. Temporal behavior of soft X-ray radiation of these impurities was analyzed with the STRAHL code to obtain radial profiles of impurity transport coefficients. The diffusion of both impurities is enhanced outside of ECH resonance, while inside the transport is neoclassical. Comparison of the measured transport coefficients for Al and W impurity transport with the TGLF and CGYRO modeling will be presented for various heating levels and deposition locations, spanning a wide range of electron/ion heat fluxes and mixes of turbulent modes.