Validating Impurity Modeling on WEST through a Synthetic Diagnostic Workflow*

We present 2D simulations using an iterative synthetic diagnostic workflow and compare them against experimental measurements. This work primarily focuses on oxygen (O), assumed to be the dominant source of tungsten (W) sputtering, and includes experimental and modeling power scans conducted on the WEST platform. This approach provides valuable insights into the role of high O charge states on W PFC erosion. Since fusion devices often suffer from limited poloidal diagnostic coverage, it is difficult to determine impurity distributions across the poloidal extent for an accurate interpretation of experimental results. Our workflow commences with a fixed background hydrogenic plasma obtained from the multifluid MHD code SOLEDGE3X. This plasma is then employed in the global impurity transport code GITR to determine the charge state abundances of O and W across the poloidal cross-section. Subsequently, the abundances are transformed into spectral line intensities utilizing the collisional radiative code ColRadPy. To incorporate the 3D effects of sightlines and reflections from in-vessel components, we leverage Raysect. Initial comparison of experimental measurements with synthetic results focus on the self-consistent validation of O-II and W-I emission. Agreement between measurements and numerical codes is found by carefully optimizing the transport coefficients, and we spatially modify the gridded charge state distribution to achieve consistency between the synthetic and experimental outcomes. Finally, we will discuss how this approach can help comprehensively understand W erosion from light impurities.