Comprehensive Screening of Plasma-Facing Materials for Nuclear Fusion

Plasma-facing materials (PFMs) represent one of the most significant challenges in the design of future nuclear fusion reactors. Inside the reactor, the divertor experiences the harshest material environment: intense neutron and plasma bombardment coupled with extremely large heat fluxes. Tungsten is the material chosen for ITER due to its properties, though it still faces several challenges in a reactor environment. This work provides a comprehensive screening of candidate PFMs based on experimentally known materials. The methodology to identify the most promising PFMs combines peer-reviewed data of inorganic crystals from the Pauling File database and first-principles DFT calculations of two key PFMs properties, namely the surface binding energy and the formation energy of hydrogen interstitials. The materials that meet the necessary thermal performance to withstand heat loads are critically compared with the state-of-the-art literature, defining an optimal subset where to perform first-principles calculations. Well-known PFMs - such as W, Mo, and carbon-based materials - are captured by this screening, along with less familiar refractory materials that warrant further investigation.