Oxygen collection in the limiter shadow of TEXTOR depending on wall conditioning with boron
A model equation is found empirically from collector probe experiments in the SOL of TEXTOR which relates the collected amounts of oxygen on graphite targets to the codeposited boron and deuterium rates and to the OI light emission measured in the SOL. Gettering, absorption and sticking, respectively, could be identified as most likely contributing mechanisms. The oxygen contamination in the plasma remains low after boronisation because of the formation of stable oxides due to the energetic ion deposition. The dependence of one of the terms on the OI light intensity in the SOL should allow the study of the relation to the oxygen ion flux. It is suggested, however, that 18O is used as a tracer in such an experiment, in order to avoid the uncertainties with oxygen absorbed from air.
Bibliographic Reference: Article: 18th European Conference on Controlled Fusion and Plasma Physics, Vol. III (1991) pp. 165-168
Record Number: 199111397 / Last updated on: 1994-12-02
Original language: en
Available languages: en