A key question of long-pulse operation in the stellarator Wendelstein 7-X (W7-X) is the net
erosion of plasma-facing components (PFCs), which determines W7-X PFC lifetimes as well
as the impact on the impurity influx to the plasma. In order to judge the erosion and
deposition balance at the passively cooled graphite divertor, a set of exchangeable graphite
tiles with marker layer stripes consisting of 5–10 μm C deposited on a 200 nm thick Mo
interlayer were installed as an integral part of the divertor surface and removed at the end of …

… Ex-situ Analysis of W7-X Divertor Plasma-facing Components by Picosecond Laser
Diagnostics … W7-X: Operations (OP), Max Planck Institute for Plasma Physics, Max Planck
Society; … Stellarator Edge and Divertor Physics (E4), Max Planck Institute for Plasma
Physics, Max Planck Society; …