Normal high velocity solid dust impacts on tiles of tokamak-relevant temperature

• Published in: Nuclear materials and energy 2024-12, Vol.41, p.101735, Article 101735
• Main Authors: De Angeli, Marco, Tolias, Panagiotis, Suzuki-Vidal, Francisco, Ripamonti, Dario, Ringrose, Tim, Doyle, Hugo, Daminelli, Giambattista, Shadbolt, Jay, Jarvis, Peter, De Angeli, Monica
• Format: Article
• Language: English
• Subjects: Damage laws; Dust in tokamaks; Mechanical impacts; Runaway electron impact; Wall cratering
• ISSN: 2352-1791; 2352-1791
• DOI: 10.1016/j.nme.2024.101735

Runaway electron incidence on plasma facing components triggers explosive events that are accompanied by the expulsion of fast solid debris. Subsequent dust-wall high speed impacts constitute a mechanism of wall damage and dust destruction. Empirical damage laws that can be employed for erosion estimates are based on room-temperature impact experiments. We use light-gas gun shooting systems to accelerate solid tungsten dust to near-supersonic speeds towards bulk tungsten targets that are maintained at different temperatures. This concerns targets cooled down to −100°C with liquid nitrogen and targets resistively heated up to 400 °C. Post-mortem surface analysis reveals that the three erosion regimes (plastic deformation, bonding, partial disintegration) weakly depend on the target temperature within the investigated range. It is concluded that empirical damage laws based on room-temperature measurements can be safely employed for predictions. •W-on-W normal impact cratering studied at target temperatures from −100 °C to ＋400 °C and impact speeds within 630–3100 m/s.•The crater morphology and different impact regime boundaries have a very weak dependence on the target temperature.•Established empirical damage laws, based on room-temperature measurements, have been compared to the experimental results.•The empirical room temperature damage laws can be safely employed for crater volume predictions, at least within the studied temperature range.