The plasma facing surfaces of Tokamaks and Stellarators can be heat-treated (baked) or bombarded with energetic particles (discharge cleanings, refer to FusionEPtalks #15) to optimize their effect of fusion plasma. Alternatively, these surfaces can be coated with chemically active materials like Boron (B). These "getters films" retain impurities and cold fuel particles, whereby reducing the power losses and easing access to the high-performance regimes of interest. Lithium (Li) offers addition a broad range of in-vessel applications e.g. liquid targets, vapor-box divertor or edge-localized mode pacing. Enhanced confinement times, high-pressure pedestals and smoothed temperature gradients have also been observed under extensive Li coverage. In TJ-II, the deposition of a Boron film before lithiation was found to extend the lifetime of the very reactive Li film. During his Master thesis, the speaker explored the effect of this substrate and noticed a resilience to molecular oxidation, a consistent D retention and a large recovery of the gettering properties following a helium discharge treatment. In this talk, the speaker will review the benefits of Li wall-conditioning and discuss the synergies observed with a B (C) substrate.
Presented by Alexis Rustam Devitre (PhD candidate at Ghent University, Belgium).
FusionEPtalks is brought to you by the alumni community of the European Master In Fusion Science and Engineering physics. Our mission is to do student-led webinars, expert talks and panels on the development of nuclear fusion as an energy source that connect scholars, engineers and enthusiasts around the world.