Characterization and Scaling of Heat Flux Transport in the DIII-D SOL

In this study, we compare the divertor heat flux profile (width) to the upstream $T_e$ profile in DIII-D. It is generally thought that the parallel heat flow in the scrape off layer (SOL), in competition with cross-field transport, governs the heat flux to the divertor. The relative importance of conduction versus convection within the SOL is not yet completely quantified for many operating regimes. In this study, we focus on an operational regime that generates Type I edge localized modes (ELMs). Two diagnostics, a fast framing IRTV and a Thomson scattering system, allow us to examine the relative role of conduction and convection of the $T_e$ channel by comparing the upstream $T_e$ width with the heat flux width in the divertor. We will present data scalings for a number of parameters scans including variations of plasma current, plasma density, and toroidal field at constant safety factor and input power.