Multi-ion fluid simulation of tokamak edge plasmas including non-diffusive anomalous cross-field transport

The two-dimensional, multi-ion, fluid code UEDGE is used to simulate the sophisticated transport of impurities in the tokamak edge plasma. The UEDGE model incorporates the effects of non-diffusive intermittent cross-field transport by using anomalous convective velocities whose spatial profile is adjusted for each ion charge state to match available experimental data. The simulations of low-confinement (L-mode) shots indicate that: (i) anomalous convective transport dominates in the far scrape-off layer; (ii) different impurity charge states have different magnitudes and signs in their convective velocities; and (iii) chamber wall sputtering is an important source of impurities.