Charge-State Resolved Impurity Dynamics in the Scrape-Off Layer of WEST

Understanding the evolution of impurity charge states in the scrape-off layer (SOL) is essential for predicting wall erosion, impurity transport, and plasma contamination in high‑Z wall tokamaks. We employ a full-orbit Monte Carlo particle tracer to model the trajectories and ionization histories of sputtered tungsten and light impurities such as boron, carbon, and oxygen in the WEST SOL, using experimentally constrained background density and temperature profiles. The simulation resolves fractional charge-state abundances across the SOL and computes the ionization times and distances for each species, enabling identification of the penetration depth of impurity charge states. Initial sputtering distributions are obtained using RustBCA, and local sheath electric field profiles used for charge-state dependent screening are extracted from hPIC2simulations. Additionally, the charge dependent impurity flux entering the core is extracted to provide self-consistent source terms for core impurity transport modeling.