IMPACT OF MOLYBDENUM AND TUNGSTEN TEST LIMITERS ON ION FLUXES IN THE PLASMA EDGE OF TEXTOR

Citation
M. Rubel et al., IMPACT OF MOLYBDENUM AND TUNGSTEN TEST LIMITERS ON ION FLUXES IN THE PLASMA EDGE OF TEXTOR, Journal of nuclear materials, 249(2-3), 1997, pp. 116-120
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Nuclear Sciences & Tecnology","Mining & Mineral Processing","Material Science
ISSN journal
0022-3115
Volume
249
Issue
2-3
Year of publication
1997
Pages
116 - 120
Database
ISI
SICI code
0022-3115(1997)249:2-3<116:IOMATT>2.0.ZU;2-V
Abstract
Ion fluxes in the scrape-off layer (SOL) of the TEXTOR tokamak were tr aced by means of the collector probe technique during tests of tungste n and molybdenum limiters. Graphite probes were exposed under differen t operation conditions: limiter position, plasma density, neon edge co oling and heating mode. Following the exposures, the surfaces were exa mined with ion beam analysis techniques (RBS, NRA) in order to determi ne deposition rates of metals, deuterium and other species. Under the same experimental conditions deposition rates of tungsten are found to be 6.5-7.5 times lower than those for molybdenum. The results for bot h the metals are compared and discussed in terms of processes governin g the erosion rate of high-Z metals in tokamaks: physical sputtering a nd re-deposition of sputtered species. Moreover, the results of the co llector probe measurements of fluxes in the SOL are compared with the spectroscopic observations of high-Z impurity atoms in the plasma. (C) 1997 Elsevier Science B.V.