Wall cratering upon high velocity normal dust impact

TL;DR

This study investigates the erosion effects of high velocity tungsten dust impacts on tungsten surfaces, identifying three erosion regimes and deriving empirical damage laws to predict erosion in future fusion reactors.

Contribution

It provides controlled experimental data on dust impact erosion regimes and introduces empirical damage laws for erosion estimation in fusion reactor environments.

Findings

Three erosion regimes identified: plastic deformation, bonding, disintegration.

Empirical damage laws derived for the disintegration regime.

Large impact statistics enable reliable erosion predictions.

Abstract

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.