Author/Authors :
Ueda، نويسنده , , Y. and Fukumoto، نويسنده , , M. and Yamawaki، نويسنده , , A. and Soga، نويسنده , , Y. and Ohtsuka، نويسنده , , Y. and Brezinsek، نويسنده , , S. and Hirai، نويسنده , , T. and Kirschner، نويسنده , , A. and Kreter، نويسنده , , A. and Litnovsky، نويسنده , , A. and Philipps، نويسنده , , V. and Pospieszczyk، نويسنده , , A. and Schweer، نويسنده , , B. and Sergienko، نويسنده , , G. and Tanabe، نويسنده , , T. and Sugiyama، نويسنده , , K. and Ohya، نويسنده , , K. and Ohno، نويسنده , , N.، نويسنده ,
Abstract :
New results are shown on carbon deposition and mixed layer formation on tungsten surfaces in TEXTOR test limiter experiments by varying surface conditions such as surface roughness (Ra: 10 nm–1 μm), temperature (300–900 °C), and initial surface carbon concentration (0–60%). It is found that surface roughness significantly affected C deposition for both W and graphite substrates such as increase in the C deposition and extension of the C deposition area. Not only the surface roughness parameter Ra but also detailed surface morphology closely relate to C deposition on tungsten. Carbon deposition hardly occurred at least above ∼520 °C on tungsten under TEXTOR edge plasma conditions. Carbon behavior on tungsten at 770–930 °C depends on the incident carbon ion energy. Although tungsten and carbon mixing layers affected C deposition, their effect is less than the roughness effect.
