Removal of redeposited layers and hydrogen release by oxygen ventilation of TEXTOR-94
Abstract
Ventilation of the TEXTOR torus with oxygen at pressures between 0.007 and 0.3 mbar and at wall temperatures between 500 and 700 K has been investigated to remove redeposited carbon material and to release the incorporated hydrogen. It has been observed that a significant part of the injected oxygen adsorbs on the walls due to formation of stable oxygen compounds. Part of the oxygen reacts with CO and CO 2. The CO reaction rate is independent of the filling pressure whereas the CO 2 production increases with increasing pressure. Plasma operation after the oxygen baking has been achieved after GDC in D 2 and He (15-30 min). The oxygen impurity content was initially about a factor of 2-3 higher than before but also showed a decreasing behaviour shot by shot.
- Publication:
-
Journal of Nuclear Materials
- Pub Date:
- 1999
- DOI:
- 10.1016/S0022-3115(98)00825-3
- Bibcode:
- 1999JNuM..266..386P