Application of tungsten for plasma limiters in TEXTOR
2000 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 283, 1128-1133 p.Article in journal (Refereed) Published
Three different types of W limiters were exposed in the TEXTOR plasma and the response of the plasma and materials performance of the limiters were investigated. 1. A W bulk limiter operated with preheating above 800 K withstood a plasma heat load of about similar to 20 MW/m(2) for a few seconds with some slight surface melting during the highest heat load shot. However, it was severely damaged when operated at around 500 K. 2. A C/W twin test limiter, half made of bulk W and the other half of graphite (EK-98) gave very useful information on how low- and high-Z materials behave under conditions of simultaneous utilization as PFM such as cross-contamination and the influence of a large mass difference on hydrogen reflection and deposition. 3. Two sets of main poloidal W limiters made of vacuum vapor sprayed (VPS)-W deposited on graphite (IG-430U) with a Re interlayer could absorb about 60% of the total convection heat and the ohmic plasma with a density as high as 5 x 10(13) cm(-3) was sustained. Most of the VPS-W coated limiters tolerated a heal load of similar to 20 MW/m(2). This series of W limiters experiments in TEXTOR has shown that W is applicable as a PFM, if its central accumulation is avoided by NBI and/or ICRH heating. Nevertheless, some concerns still remain, including difficulty of plasma startup, W behavior in higher temperature plasmas, and materials' selection.
Place, publisher, year, edition, pages
2000. Vol. 283, 1128-1133 p.
IdentifiersURN: urn:nbn:se:kth:diva-20229DOI: 10.1016/S0022-3115(00)00119-7ISI: 000165877800081OAI: oai:DiVA.org:kth-20229DiVA: diva2:338922
QC 201005252010-08-102010-08-10Bibliographically approved