  Dust-wall high speed impacts, triggered by the termination of runaway
electrons on plasma facing components, constitute a source of erosion. Normal
high velocity mechanical impacts of tungsten dust on bulk tungsten plates are
reproduced in a controlled manner by light gas gun shooting systems.
Post-mortem surface analysis revealed that three erosion regimes are realized;
plastic deformation, bonding and partial disintegration. The large impact
statistics allowed the extraction of reliable empirical damage laws in the
latter regime, which can be employed for erosion estimates in future reactors.
