Erosion of iron-tungsten model films by deuterium ion irradiation: a benchmark for TRI3DYN

The state-of-the-art 3D version of the Monte Carlo sputtering code TRI3DYN was benchmarked with experimental results obtained for iron-tungsten model films. The data which served for comparison concerned: (a) the mass removal rate for Fe-W films (with 1.5 at% W) by prolonged deuterium ion bombardment at 250 eV measured with the quartz crystal microbalance (QCM) technique as a function of ion fluence (up to a total fluence of 4 x 10(23) m(-2)); (b) the change in surface morphology as measured by atomic force microscopy, and; (c) the change in elemental surface compositions as determined by different surface analytical techniques. Our benchmarking studies show that the code TRI3DYN is able to predict the outcome of the experiments, if the information about the initial surface morphology and elemental depth profile measurements of the sample are taken into account. It is not only the dynamical behaviour of the erosion yield with ion fluence that can be reproduced, but also the emerging surface pattern and the observed tungsten enrichment at the structured surface. The code provides a first insight into the reasons for the high influence of surface roughness at the nm scale on the sputtering behaviour of the plasma facing components (PFCs).