Erosion/redeposition at the JET MkI divertor

The DIVIMP/NMBUS codes are employed to simulate divertor carbon profiles and the net erosion measured by colorimetry using the most recent chemical sputtering data and models. The relative roles of physical and chemical sputtering are assessed in terms of erosion and impurity contamination. Beryllium photon fluxes are also modelled, showing much less sputtering than predicted by the pure beryllium sputtering data. In addition, the erosion of fixed divertor target Langmuir probe tips has been measured photographically and gives an effective sputtering yield of < 0.5%.