Speaker: Dr. Daniel Andruczyk, University of Illinois at Urbanan-Champaign
Abstract: Why does the Sun work? This is an important and nuanced question and the answer potentially tells us how we need to run a fusion reactor. But in doing so it exposes one of the main issues in fusion. To truly achieve a steady state working fusion power plant there is a major hurdle that needs to be overcome, plasma material interactions (PMI). The materials used to build these devices are extremely important. Traditionally solid materials (tungsten, molybdenum, carbon, etc.) have been used but encounter many issues when exposed to the high heat fluxes in the divertor region, which can reach 40 MWm-2 or more in some cases. Interactions with energetic ions, neutrals and neutrons can cause surface morphology changes (DPA, transmutation, fuzz, bubbles, blisters), ejection of material into the plasma, recycling of cold neutral gas back into the plasma and fuel depletion through implantation into the material. It turns out there may be a solution, liquid metals, and in particular liquid lithium (Li), which offer several solutions to many of the issues solid materials face. There are still technological challenges using liquid Li, and these are all under investigation and development. This talk will focus on PMI challenges and how Li can solve many of these issues. Why does the Sun work? … the answer to come!