Modelling of new type of wall for fusion reactors and plasma-liquid metal interactions

Compact fusion reactors subject plasma-facing components to heat and particle fluxes that may exceed the limits of conventional materials such as tungsten. Liquid lithium components offer a promising alternative, but their erosion can lead to lithium contamination of the plasma. This thesis investigates the chain of physical processes involved in lithium transport, from the plasma-facing walls to the plasma core. Estimates show that lithium evaporation can modify the properties of the near-wall region, known as the sheath, as well as the associated redeposition mechanisms. In particular, it leads to strong redeposition of evaporated lithium, whereas the redeposition of lithium originating from wall sputtering is much lower.In the plasma core, lithium transport is primarily dominated by turbulence. Our work shows that thermodiffusion and transport barriers can limit lithium accumulation. These mechanisms could therefore enable the use of liquid lithium in fusion reactors without compromising their performance. Nevertheless, such an application remains conditional on appropriate reactor design and operational strategies.

PhD thesis supervision
Jérôme Moritz (Supervisor), IJL, CNRS-University of Lorraine (Team 107)
Etienne Gravier (Co-supervisor), IJL, CNRS-University of Lorraine (Team 107)

Examination committee
Prof. Alessandro Biancalani (Reviewer), ESILV
Dr. Yann Camenen (Reviewer), PIIM, CNRS-Aix-Marseille University
Prof. Clotilde Boulanger, IJL, CNRS-University of Lorraine
Prof. Kristel Crombé, University of Ghent
Dr. James P. Gunn, CEA-IRFM