<i>In situ</i> microscopy for plasma erosion of complex surfaces

A novel method for the in situ visualization and profilometry of a plasma-facing surface is demonstrated using long-distance microscope. The technique provides valuable monitoring microscopic temporal morphological evolution material subject to plasma–surface interactions, such as ion-induced sputter erosion. Focus variation image stacks enables height profilometry, which allows depth field beyond limits associated with high magnification. As demonstration this capability, erosion volumetrically featured aluminum foam quantified during ion-bombardment low-temperature argon plasma where electron temperature ∼7 eV biased relative target that ions impinge at ∼300 eV. Three-dimensional maps are reconstructed from images captured microscope an x–y resolution 3 × μm2 focus-variation based on motor step-size 20 μm. time-resolved show total recession 730 μm significant ligament thinning over course 330 min exposure. This can be used developing components wide range devices applications propulsion, manufacturing, hypersonics, fusion.