Simulation calculations of mutual contamination between tungsten and carbon and its impact on plasma surface interactions

Mutual contamination between C and W, resulting from the simultaneous use o f these materials as plasma facing components, is simulated by means of a c omputer simulation code, Erosion and Deposition based on Dynamic model (EDD Y). W deposition on C rapidly increases the reflection coefficient for D an d C impurity. In comparison between the calculation and a C-W twin test lim iter experiment in TEXTOR-94, C release from the C side of the limiter is d ominated by reflection of C impurity from the W deposits, in addition to ph ysical sputtering of C; chemical erosion is strongly suppressed. Due to the dynamic effect which makes C-W mixed layer, C deposition on W gradually ch anges the reflection coefficient and sputter yields. Formation of a sharp b oundary 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 o n the limiter surface are also calculated. (C) 2001 Elsevier Science B.V, A ll rights reserved.