Estimates of RF induced sputtering and impurity emission from the ICRH actuators on SPARC

We present preliminary estimates of the impurity fluxes emitted by the plasma-facing components of the ICRF antennas and surrounding structures on the SPARC tokamak during burning-plasma operations. The VSim code (Tech-X) has been employed to solve the electromagnetic fields emitted by the ICRF antenna, considering dedicated RF-sheath boundary conditions and realistic 3D geometry. The output from these simulations has served as input for the hPIC2 and RustBCA codes at UIUC, enabling an accurate determination of ion impact energy-angle distributions and material surface response, including sputtering, reflection, and implantation. The calculations have been performed for a realistic plasma composition, taking into account multiple impurities, and at a millimeter-scale resolution. The approach allows a thorough exploration of areas with the highest erosion rates, and the identification of potential mitigation strategies. A detailed analysis of the RF limiters, Faraday rods, and other critical components surrounding the ICRF actuators has been performed. Analyses at different levels of RF power and far-SOL conditions allow to constrain the expected erosion rates and make preliminary considerations on core compatibility during ICRF heating. Work supported by Commonwealth Fusion Systems.