title: Actinic damage of Y/Mo multilayer optics in a table-top plasma-driven x-ray laser.
abstract: A Y/Mo multilayer coating, optimized for top reflectivity at λ=12  nm, has been nano-inspected after long-term operation at the in-house soft x-ray laser. The surface and optical inspections were complemented by electron microscopy on cross sections, prepared with focused ion beam technology. A factor of 2.5 loss of reflectivity in the exposed area (ca. 30% relative loss every 100 shots), with concomitant nanoscale photodamage and particle fallout, was found. The x-ray-laser-induced damage extended as deep as 250 nm beneath the surface and as wide as the millimeter spot size.
authors.forename: Davide
authors.initials: D
authors.lastname: Bleiner
authors.forename: Sergiy
authors.initials: S
authors.lastname: Yulin
authors.forename: Julia
authors.initials: J
authors.lastname: Martynczuk
authors.forename: Mabel
authors.initials: M
authors.lastname: Ruiz-Lopez
authors.forename: Yunieski
authors.initials: Y
authors.lastname: Arbelo
authors.forename: Jürg E
authors.initials: JE
authors.lastname: Balmer
authors.forename: Detlef
authors.initials: D
authors.lastname: Günther