The removal of co-deposited carbon/deuterium films from stainless steel and tungsten by transferred-arc cleaning

Deuterium and carbon were co-deposited onto tungsten and stainless steel sa mples using a deuterium plasma seeded with varying amounts of deuterated me thane to simulate carbon-based deposited layers in magnetic-confinement fus ion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by io n beam analysis both before and after cleaning to determine deuterium and c arbon concentrations present, The extent of TA cleaning was varied to deter mine the deuterium and carbon removal efficiency and sample erosion rate. T he deuterium content was greatly reduced by the cleaning, thus demonstratin g the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. The TA removal of car bon, tantalum and molybdenum contaminants from the same samples was also qu antified. Removal of surface layers and significant reduction of subsurface concentrations of these contaminants were observed. (C) 2001 Elsevier Scie nce B.V. All rights reserved.