Simulation of Diffusive Lithium Evaporation Onto the NSTX Vessel Walls
Authors: D.P. Stotler, C.H. Skinner, W.R. Blanchard, P.S. Krstic, H.W. Kugel, H. Schneider, and L.E. Zakharov
Abstract: A model for simulating the diffusive evaporation of lithium into a helium filled
NSTX vacuum vessel is described and validated against an initial set of deposition experiments. The DEGAS 2 based model consists of a three-dimensional representation
of the vacuum vessel, the elastic scattering process, and a kinetic description of the evaporated atoms. Additional assumptions are required to account for deuterium
out-gassing during the validation experiments. The model agrees with the data over a range of pressures to within the estimated uncertainties. Suggestions
are made for more discriminating experiments that will lead to an improved model.
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Submitted to: Journal of Nuclear Materials (May 2010)
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