High radiation from intrinsic and injected impurities in Tore Supra ergodic divertor plasmas
The present article reports experiments aimed at comparing several impurity mixtures (C, O, Cl, N, Ne, Ar) regarding their capability to reduce the power load on the divertor target plates. The divertor conditions required for each mixture to minimize the parallel power flux are determined, along with the resulting core effective charge Z(eff) and volume averaged density. The radiation efficiency (ratio of edge radiation to plasma core contamination) of intrinsic carbon is found to increase with the total injected power. In the impurity injection experiments, nitrogen is found to be the best choice to reduce the power flux to the target plates: it has the same characteristics as C/O radiation (low core contamination), and it can be controlled. The low Z(eff) observed in this case is attributed to the large value of the screening of the radiating ionization stages of the impurity.
Bibliographic Reference: An article published in: Journal of Nuclear Materials, Vol.290-293 (2001), pp.925-929
Record Number: 200113818 / Last updated on: 2001-10-04
Original language: en
Available languages: en