Fuel removal from plasma-facing components by oxidation-assisted technique : An overview of surface morphology after oxidation

• Oxygen-assistedfuelremoval is reported for laboratory-prepared a-C:D films and for layers obtained by boronisation in a tokamak and then exposed to a helium–oxygen glow discharge in TEXTOR. Oxidation of thick mixed-material co-deposits under laboratory conditions is also presented. The essential results are following: (i) laboratory-prepared amorphous deuterated carbon (a-C:D) layers are decomposed efficiently by the He–O2 glow: D and C contents are decreased by a factor of 45–220 and 25–60, respectively; (ii) the same treatment of the boronised films leads to the release of D but no removal of carbon is observed; (iii) the thermal oxidation (at 300 °C in air under laboratory conditions) of co-deposits on PFC and probes exposed to the SOL reduces the D content by a factor of 4–5 after 2 h, whereas nearly complete fuelremoval (98%) occurs after 10 h at 300 °C. The study shows that the fuelremoval efficiency is dependent on the overall composition of the mixed layer. It is high from pure a-C:D films but distinctly less efficient from real co-deposits.

Subject headings

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Keyword

Deuterium inventory

Retention

Surface analysis

Co-deposition

TEXTOR

Publication and Content Type

ref (subject category)

art (subject category)