Preparations for liquid tin plasma-surface interaction and transport experiments in LTX-beta*

Liquid tin is considered a candidate for the divertor and first wall of fusion plasma devices, thanks to its low melting temperature and low evaporation rate. Experiments with a liquid tin probe are planned in the small spherical tokamak LTX-beta with expected central electron temperatures up to 200-300 eV with auxiliary NBI heating. Experiments are aimed at 1) Assessing physical sputtering and evaporative fluxes using Sn I - Sn III ultraviolet and visible emission line intensities, and 2) Assessing core impurity transport with well characterized tin source using Sn V – Sn XX spectra from an extreme ultraviolet spectrometer. Spectra modeling is based on the new atomic data generated by HULLAC and FAC atomic codes. Impurity transport code STRAHL with new ionization and recombination rates generated by FLYCHK code is used to look for significant spectral emission differences in plasma scenarios with LTX-like transport, flat and peaked kinetic plasma profiles and various fractions of lithium and tin impurities.