| 1. |
- Ohya, K., et al.
(författare)
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Simulation calculations of mutual contamination between tungsten and carbon and its impact on plasma surface interactions
- 2001
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Ingår i: Journal of Nuclear Materials. - 0022-3115 .- 1873-4820. ; 290, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- Mutual contamination between C and W, resulting from the simultaneous use of these materials as plasma facing components, is simulated by means of a computer simulation code, Erosion and Deposition based on Dynamic model (EDDY). W deposition on C rapidly increases the reflection coefficient for D and C impurity. In comparison between the calculation and a C-W twin test limiter experiment in TEXTOR-94, C release from the C side of the limiter is dominated by reflection of C impurity from the W deposits, in addition to physical sputtering of C; chemical erosion is strongly suppressed. Due to the dynamic effect which makes C-W mixed layer, C deposition on W gradually changes the reflection coefficient and sputter yields. Formation of a sharp boundary between erosion and C deposition zones on the W side of the limiter is well reproduced by simulation. Local redeposition patterns of C and W on the limiter surface are also calculated.
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| 2. |
- Ohya, K., et al.
(författare)
-
Simulation study of carbon and tungsten deposition on W/C twin test limiter in TEXTOR-94
- 2000
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Ingår i: Journal of Nuclear Materials. - 0022-3115 .- 1873-4820. ; 283, s. 1182-1186
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate the impurity release and surface modification on a W/C twin test limiter, made of a half of W and the other half of C, exposed to the edge plasma of TEXTOR-94, simulation calculations of ion-surface interaction are conducted by a Monte Carlo code. According to the calculations, experimentally observed spatial distributions of WI and CII line intensities around the W side of the limiter can be explained by physical sputtering of W, reflection of bombarding C ions and physical sputtering of implanted C. The CII line emission, resulting from thermal C atoms, around the C side of the limiter is suppressed by deposition of W, and the reflection of C ions from W deposited on C causes the CII intensity to decay more slowly than that from C without the deposition. Bombardment with deuterium edge plasmas, containing impurity W, produces a thick W layer on the C side of the limiter, whereas C implanted in the W side is strongly sputtered due to impact of most constituent D ions.
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