Measurements and SOLPS-ITER Modelling of Pumping Experiments in DIII-D

Carefully selecting cross-field transport coefficients, particle and energy sources, and particle removal rates to reflect experimental conditions is shown to improve agreement between boundary plasma and neutral modelling using the SOLPS-ITER code and experimental measurements from Langmuir probes and pressure gauges in H-mode plasmas in the DIII-D tokamak. However, modifying diffusive transport coefficients to match upstream plasma profiles alone is shown to result in a significant underprediction of target plasma fluxes in the cases explored. This result holds regardless of whether diffusive transport is expressed as poloidally symmetric or given a ballooning structure. Using ion temperature measurements from main ion charge exchange to determine ion thermal transport is also shown to enable agreement of upstream kinetic profiles between SOLPS and measurements, whereas the model finds measurements of impurity ion temperature to be inconsistent with other profile inputs. This work identifies boundary plasma model deficiencies and enables proper model validation exercises as models are improved.