title: Damage investigation on tungsten and diamond diffractive optics at a hard x-ray free-electron laser.
abstract: Focusing hard x-ray free-electron laser radiation with extremely high fluence sets stringent demands on the x-ray optics. Any material placed in an intense x-ray beam is at risk of being damaged. Therefore, it is crucial to find the damage thresholds for focusing optics. In this paper we report experimental results of exposing tungsten and diamond diffractive optics to a prefocused 8.2 keV free-electron laser beam in order to find damage threshold fluence levels. Tungsten nanostructures were damaged at fluence levels above 500 mJ/cm(2). The damage was of mechanical character, caused by thermal stress variations. Diamond nanostructures were affected at a fluence of 59 000 mJ/cm(2). For fluence levels above this, a significant graphitization process was initiated. Scanning Electron Microscopy (SEM) and µ-Raman analysis were used to analyze exposed nanostructures.
authors.affiliation: Biomedical & X-Ray Physics, Department of Applied Physics, Royal Institute of Technology, KTH-AlbaNova, SE-106 91, Stockholm, Sweden. fredrik.uhlen@biox.kth.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Uhlén
authors.forename: Daniel
authors.initials: D
authors.lastname: Nilsson
authors.forename: Anders
authors.initials: A
authors.lastname: Holmberg
authors.forename: Hans M
authors.initials: HM
authors.lastname: Hertz
authors.forename: Christian G
authors.initials: CG
authors.lastname: Schroer
authors.forename: Frank
authors.initials: F
authors.lastname: Seiboth
authors.forename: Jens
authors.initials: J
authors.lastname: Patommel
authors.forename: Vivienne
authors.initials: V
authors.lastname: Meier
authors.forename: Robert
authors.initials: R
authors.lastname: Hoppe
authors.forename: Andreas
authors.initials: A
authors.lastname: Schropp
authors.forename: Hae Ja
authors.initials: HJ
authors.lastname: Lee
authors.forename: Bob
authors.initials: B
authors.lastname: Nagler
authors.forename: Eric
authors.initials: E
authors.lastname: Galtier
authors.forename: Jacek
authors.initials: J
authors.lastname: Krzywinski
authors.forename: Harald
authors.initials: H
authors.lastname: Sinn
authors.forename: Ulrich
authors.initials: U
authors.lastname: Vogt
mesh_terms: D018130:Diamond / Q000737:chemistry* / Q000528:radiation effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D007909:Lenses; D011829:Radiation Dosage; D012031:Refractometry / Q000295:instrumentation*; D014414:Tungsten / Q000737:chemistry* / Q000528:radiation effects*; D014965:X-Rays
chemical_list: D018130:Diamond; D014414:Tungsten