Overview of material migration and mixing, fuel retention and cleaning of ITER-like castellated structures in TEXTOR

Deposits containing up to 70 at.% of tungsten on the gap areas closest to the plasma were detected in recent experiments. Deposition in the gaps accompanied by metal mixing demand for development of effective cleaning techniques. In experiments with ITER-like castellation, the gaps were cleaned from carbonaceous deposits using oxygen plasmas at 350 °C. This contribution contains an overview of experimental and modeling results along with recommendations for PFCs in ITER.