Studies of carbon behavior in tungsten under carbon and hydrogen mixed irradiation

The erosion of W coatings with the different content of C was investigated in Ar and At + H-2 plasmas. The enhanced erosion was registered in At + H-2 plasma for coatings containing 40 at.% of C and more, which might be owing to chemical erosion of carbon. The erosion kinetics was analyzed together with the studies of coatings microstructure, phase composition and Vicker hardness properties. The C distribution profiles in W were investigated in dependence on the redeposition rate of sputtered C and Simultaneous 0.3 keV Ar+ ion irradiation. It is shown that C penetration depth depends on the coverage of W by C during ion irradiation. Deep C penetration was registered when W was partially covered by redeposited carbon. The computer simulation was used to extrapolate obtained results to experimental investigations performed by Ueda Y, Fukumoto M, Sawamura I, Sakizono D, Shimada T, Nishikawa M. [Fusion Eng Des 2006;81:233-9]. It is revealed that the ballistic relocation of implanted C atoms is the dominant process which explains the deep penetration of C and formation of WC compound in the near-surface region of W. (C) 2009 Elsevier Ltd. All rights reserved.