Measurements of erosion mechanisms from solid and liquid materials in PISCES-B

PISCES-B is a steady-state linear-plasma simulator facility dedicated to th e study of plasma-material interactions. This paper will summarize recent e xperiments conducted in PISCES in the areas of: plasma-liquid-metal interac tions, the flux dependence of the chemical erosion of graphite, and surface modification to tungsten samples exposed to high-fluence plasmas. Enhanced erosion of liquid-metal samples exposed to plasma is observed for both lit hium and gallium samples. The surface stratification of liquid-metals is di scussed as a possible explanation. The importance of correction terms in th e interpretation of the chemical erosion measurements from graphite samples is then emphasized. And finally, surface analysis of tungsten samples, aft er deuterium plasma bombardment, has revealed microscopic damage in the sur face at ion energies below the sputtering threshold energy. This damage app ears to be due to pockets of deuterium gas forming within the tungsten and subsequently rupturing. (C) 2001 Elsevier Science B.V. All rights reserved.