Test of a carbonized molybdenum limiter in TEXTOR
An a-C:H coated Mo limiter was exposed in TEXTOR to 11 ohmic tokamak discharges. Complete erosion of the carbon film is observed at areas of largest heat flux (1100 C). This leads to an increase of the carbon concentration in the plasma. Mo is released progressively and leads to the contamination of the carbon limiters positioned in the SOL. It is liberated from there when the limiters are later exposed and Mo proliferates onto all wall areas. This may prohibit the use of unprotected Mo wall components. The formation of Mo(2)C on the limiter surface is emphasised. Retention of hydrogen from the tokamak plasma in the carbon layers and the eroded limiter may be an important process, in particular when T operation is aimed at.
Bibliographic Reference: Article: 18th European Conference on Controlled Fusion and Plasma Physics, Vol. III (1991) pp. 173-176
Record Number: 199111398 / Last updated on: 1994-12-02
Original language: en
Available languages: en