The investigation of the survivability and the changes in insulating properties of the selected ceramic materials after 10-, 100- and 1000-hours static liquid lithium exposures at 300°C.

The sustainability of commercial fusion highly depends on the efficiency of the fusion device itself. First of all, a potential fusion power plant is required to operate over a significant amount of time without frequent pauses for maintenance, which directly depends on the survivability of Plasma Facing Components. Secondly, another essential system is the blanket, responsible for heat removal and tritium fuel production. While there is significant variation on approaches of these systems, liquid lithium has shown great performance for both PFC and blanket systems. Since lithium is one of the most chemically reactive materials, it is important to investigate and to expand list of materials compatible with molten lithium. Currently most of the research into materials compatible with molten lithium is dedicated to finding the best structural material for the lithium system. However, in order to effectively operate any liquid lithium system in a fusion device, it is mandatory to expand the highly limited knowledge about compatibility of an electrically insulating material with lithium. Effective implementation of PFC lithium loops as well as blanket systems requires electrical isolation of the lithium from some parts of the system. This mitigates the problem of current loops in the system and provides opportunity to implement lithium diagnostics. This work is dedicated to the investigation of the corrosion properties of various insulating materials by exposing them to molten lithium. The work is done in the MALiCE setup, housed at the Center for Plasma Material Interaction at the University of Illinois Urbana-Champaign. Since a candidate material is supposed to be used under high temperature conditions in the liquid lithium environment, only high-temperature ceramics were chosen to be tested. Potential insulator candidates were exposed to static molten lithium at 300 degrees Celsius for 10, 100, and 1000 hours. The degree of damage to the ceramics by lithium corrosion was determined by assessing the changes in the mass of the samples, their surface characteristics and changes in the insulating performance of the samples. The results of this work are an overview of the aforementioned characteristics for a set of ceramics from the point of view of their applicability as insulating materials in future lithium systems.