EFD-C(13)01/10 Determination of Be Sputtering Yields from Spectroscopic Observations at the JET ILW based on 3D ERO Modelling

Estimations of the ITER first wall (FW) life time, previously made by the 3D Monte- Carlo ERO code, depend strongly on the assumptions of the physical sputtering yield for beryllium (Be). It is of importance to validate the respective model and data at existing devices including the JET ITER- Like Wall (ILW) as most ITER- relevant experiment. Applying the same sputtering input data in ERO as before in the ITER- predictions, the ERO simulations for the Be light intensity (up- to- date atomic data is used) near the solid Be limiter in the JET- ILW case reveal a factor 2 overestimation of the assumed yield even if the low estimate assuming 50% D surface content is used. This result indicates the preference of this assumption for plasma- wetted areas. It points to a possible (after eliminating of uncertainties) necessity to correct (reduce) the respective estimates for the Be sputtering yield and accordingly, re- visit the ITER FW life time predictions.