Overview of HIDRA and MEME Research with at the University of Illinois*

Fusion and liquid metal research has many different avenues at the Center for Plasma Material Interactions (CPMI). Two of those are through the National Liquid Metal PFC (NLMP) program which is a multi-institutional collaboration to develop a flowing liquid lithium divertor. This program is aimed at designing and developing a flowing liquid metal divertor for FNSF. The role of CPMI is to do many of the lithium and material compatibility studies related to flow, surface wetting, and surface damage as well as understanding the role vapor shielding plays in protecting the PFC surface and heat flux dissipation through modeling and experiments. Furthermore, HIDRA, which is a l = 2, m = 5 steady-state classical stellarator is now fully operational with routine plasma operation with discharge lengths between t = 60 – 1000 s. A material analysis test-stand has been developed to expose different materials to HIDRA’s plasma discharges, including with lithium. Some of the first Li exposures in helium discharges have yielded interesting results that may have implications in how helium can be removed by lithium. Finally, the LiMIT concept, which is a self-pumping PFC based on TEMHD, was run in EAST in January 2020. This was the first full scale deployment of LiMIT in a reactor and the first results have been obtained showing that the plate was able to operate well under the EAST operating conditions. This presentation will introduce important results in HIDRA, the NLMP program, LiMIT on EAST, and look at the future of liquid metal PFC’s.