Tungsten sputtering and accumulation of implanted carbon and deuterium by simultaneous bombardment with D and C ions

Sputtering of tungsten by simultaneous incidence of gaseous and non-volatile ions is an important field of research for nuclear fusion with magnetically confined plasmas. In order to investigate the underlying processes in detail, W layers deposited on graphite and Si substrates have been irradiated simultaneously with beams of 12 keV C 2 - and 9 keV D 3 + ions. The dynamics of W sputtering as well as the accumulation of implanted C and D was studied in-situ by ion beam analysis (IBA) using 2.5 MeV 3He+ ions. In this work, particularly the sputter yield of W and the implantation of C and D as a function of the C fraction in the incident flux is discussed. Comparison of experimental data to TRIDYN simulations reveal a strong contribution of surface roughness to W sputtering and C implantation. In comparison to the influence of roughness, the contribution of chemical effects appears negligible.