Efficient hydrogen and deuterium permeation reduction in Al₂O₃ coatings with enhanced radiation tolerance and corrosion resistance

One of the major bottlenecks in the development of the breeding blanket of the DEMO fusion is the suppression of tritium permeation through structural steels as well as their against dissolution-corrosion by interaction with high temperature heavy liquid. Reduction of tritium permeation and corrosion of structural steels are crucial issues order to enhance reactor safety and avoid operational implications. As a solution to these daunting challenges, we developed multifunctional alumina coatings capable to tackle, at same time, tritium permeation and Pb–Li corrosion. The coatings are deposited by pulsed deposition and are essentially amorphous, with nanocrystalline inclusions. By optimizing deposition process, we provide experimental evidence that PLD-grown alumina yields a reduction factor for hydrogen and deuterium well above 104, even after electron, and a suitable protection against corrosion by the Pb–16Li eutectic. Given these, the multifunctional, PLD-grown alumina coatings stand out as a viable solution to of the long-lasting issues related to fusion technologies.