Interpretation of far-SOL collector probes during the SAS-VW campaign on DIII-D

Tungsten (W) deposition patterns along collector probes inserted during the SAS-VW campaign on the DIII-D tokamak plan to be interpreted with the 3D Monte Carlo code 3DLIM. W is eroded from the closed SAS-VW divertor as a trace impurity, from which it transports throughout the SOL until deposition on a collector probe or wall surface. Interpretively modelling the deposition patterns in 3DLIM enables estimating unknown parameters such as the radial transport speed of the W ions and the density of W in the SOL. By comparing the relative magnitude of W deposition on each side of the probe, the primary direction of W ions feeding into the far-SOL is measured, and results will be compared against previous results in which near-SOL W accumulation was (indirectly) measured during the 2016 DIII-D W Metal Rings Campaign (MRC). The absolute magnitude of W deposition along the probes will be compared to previous results from MRC, demonstrating how the leakage of W from a closed divertor differs from that of an open divertor such as that used in MRC. The expected results aim to show how modelling experimentally measured deposition patterns with 3DLIM enables rich interpretation of impurity transport in a region with very limited measurements.