Building database of 2D UEDGE simulations for KSTAR detachment control

A comprehensive set of 2D UEDGE simulations (~ 16k converged cases) has been obtained for KSTAR detachment control, based on the KSTAR shot (#22849). These simulations involve the variation of four control parameters: inner boundary plasma density, power input, impurity fraction and perpendicular anomalous transport coefficients. The parameter ranges encompass the normal KSTAR operation regime. The simulations assume a spatially constant concentration of impurities using a fixed-fraction model, and include the plasma potential equation and cross-field drifts. Compared to our previous work on building a large data set of 1D UEDGE simulations [1], these 2D simulations offer a higher level of fidelity by incorporating cross-field drifts, perpendicular transport and providing plasma states at both inner and outer divertor regions. The data set revels that for a specific power input and impurity fraction, the ion saturation current at the target plates exhibits a roll-over phenomenon as the upstream collisionality increases, consistent with the trend of experimental data. Furthermore, the database will soon be expanded to include a wide range of plasma operating currents and impurity species. Surrogate models are currently being developed using these simulations for enhancing KSTAR's detachment control.