Flux and energy of neutral deuterium and radial flux of neutral boron in TEXTOR
Graphite probes were exposed in TEXTOR in order to collect neutral deuterium and neutral impurities which escape radially from the plasma. A flux of neutral deuterium of approx. 2 x 1.0 E14 D(0)/cm2/s at wall radius with typical energy in excess of approx. 400 eV can be inferred from retention in graphite. The corresponding deposition rate of boron was approx 3.7 x 1.0 E12 B(0)/cm2/s in conditions with fresh boronisation and a third of that with old boronisation. This is at least two orders of magnitude more than what is expected from a simple model of radial impurity transport which takes into account diffusion, electron impact ionisation and recombination, and parallel flow in the scrape-off layer. The large impurity deposition may have implications for the interpretation of collector probe experiments, inferring ion temperatures from Larmor radius effects.
Bibliographic Reference: Article: 18th European Conference on Controlled Fusion and Plasma Physics, Vol. III (1991) pp. 129-132
Record Number: 199111393 / Last updated on: 1994-12-02
Original language: en
Available languages: en