Evidence for high-velocity solid dust generation induced by runaway electron impact in FTU

Post-mortem and in-situ evidence is presented in favor of the generation high-velocity solid dust during explosion-like interaction runaway electrons with metallic plasma-facing components FTU. The freshly-produced source secondary de-localized wall damage through impacts that lead to formation craters, which have been reproduced dedicated light gas gun impact tests. This novel mechanism, potential importance for ITER DEMO, further supported by surface analysis, multiple theoretical arguments dynamics modelling.