Plasma-Surface Interactions on Liquids

Liquid plasma-facing surfaces have been suggested as an option for advanced fusion devices, particularly in regions where solid materials may not survive over long operating periods. Because liquid surfaces can be replenished, they offer the possibility of tolerating intense particle bombardment and of recovering from off-normal events. As a preliminary step in understanding the nature of plasma-surface interactions on liquids, the authors consider some of the surface processes occurring in liquids undergoing irradiation by energetic particles. These include (1) sputtering, (2) segregation of liquid component species and impurities, (3) evaporation, and (4) trapping and release of incident particles. Aspects of these processes are examined for several candidate liquids, which represent three types of low-Z liquids: pure metals (Li), metallic alloys (Sn-Li), and compound insulators (Li{sub 2}BeF{sub 4}).