Correlating Pedestal Density Structure with Divertor Target Temperature in DIII-D

This study aims to explore potential correlations between upstream pedestal structure and divertor target conditions in order to inform self-consistent, predictive edge modeling in magnetically confined fusion plasmas. Specifically, it will examine the empirical relationship between the pedestal-to-separatrix electron density ratio n_e,ped / n_e,sep and the target electron temperature across a range of DIII-D discharges and experimental configurations. Electron temperature profiles in the divertor region are obtained using Langmuir probes and divertor Thomson Scattering (TS), while upstream densities will be determined from high spatial resolution TS measurements. The separatrix density is approximated by identifying the location in fitted profiles where the electron temperature matches that determined by power balance. By tracking the density ratio as a function of the divertor target temperature across multiple shots and conditions, potential trends will be assessed to determine whether a direct dependence exists between these quantities. This relationship could have implications for our understanding of pedestal transport physics and may provide valuable constraints for edge modeling frameworks.