Status of knowledge of chemical erosion of carbon and critical issues for extrapolation to ITER

Chemical erosion of carbon based plasma-facing materials and the re-deposition of tritium containing carbon layers are critical processes for the material choice in ITER. At the occasion of the workshop on plasma-surface interaction related to fusion (PSIF) the present status of knowledge was defined, suggestions for improved measurements discussed and the importance of atomistic modelling of individual processes underlined. In the present paper, the status of knowledge for these processes is outlined and important unresolved issues are identified: the extrapolation of measured erosion yields at high-particle fluxes towards low energies as expected in detached divertor plasmas and the transport and deposition of hydrocarbon molecules to the divertor plate and walls.