Speaker
Description
Tungsten (W) is the primary candidate material for plasma-facing components in the fusion divertor. However, the operational limits of conventional W necessitate the development of advanced variants to mitigate issues regarding brittleness and thermal stability. This research focuses on determining how specific material modifications, compositional doping and additive manufacturing (AM), collectively influences the plasma material interaction (PMI) behaviour under divertor-relevant conditions. Experiments were conducted using the linear plasma device PSI-2 to simulate high-flux plasma exposure. The study investigates two distinct material pathways: First, we evaluated the effect of advanced doping on PMI response. While these doped W variants are primarily engineered to deliver increased low-temperature ductility, superior resistance to recrystallisation and radiation induced grain growth, this study isolates how the modified microstructure influences surface evolution, damage mechanisms and retention of deuterium during plasma exposure, benchmarking this behaviour with ITER grade W. Secondly, we investigated the modification of PMI response driven by AM production methods. A comparative analysis is presented between Laser Powder Bed Fusion (L-PBF) and Electron Beam additive manufacturing. L-PBF W is used to establish the baseline PMI response for additively manufactured microstructures. This is contrasted with components produced via Electron Beam methods, a technique selected for its ability to maintain significantly higher base temperatures during fabrication. We assess how the distinct thermal histories and reduced residual stresses characteristic of the Electron Beam process alter the material's resilience to plasma-induced damage compared to the L-PBF baseline. By correlating these manufacturing and compositional variables directly with the surface morphological changes observed in PSI-2, this work clarifies the viability and progression of these novel W variants for future fusion energy applications.