title: Ronchi test for characterization of nanofocusing optics at a hard x-ray free-electron laser.
abstract: We demonstrate the use of the classical Ronchi test to characterize aberrations in focusing optics at a hard x-ray free-electron laser. A grating is placed close to the focus and the interference between the different orders after the grating is observed in the far field. Any aberrations in the beam or the optics will distort the interference fringes. The method is simple to implement and can provide single-shot information about the focusing quality. We used the Ronchi test to measure the aberrations in a nanofocusing Fresnel zone plate at the Linac Coherent Light Source at 8.194 keV.
authors.affiliation: Biomedical and X-Ray Physics, Department of Applied Physics, KTH/Royal Institute of Technology, Albanova, Stockholm SE-10691, Sweden. daniel.nilsson@biox.kth.se
authors.forename: Daniel
authors.initials: D
authors.lastname: Nilsson
authors.forename: Fredrik
authors.initials: F
authors.lastname: Uhlén
authors.forename: Anders
authors.initials: A
authors.lastname: Holmberg
authors.forename: Hans M
authors.initials: HM
authors.lastname: Hertz
authors.forename: Andreas
authors.initials: A
authors.lastname: Schropp
authors.forename: Jens
authors.initials: J
authors.lastname: Patommel
authors.forename: Robert
authors.initials: R
authors.lastname: Hoppe
authors.forename: Frank
authors.initials: F
authors.lastname: Seiboth
authors.forename: Vivienne
authors.initials: V
authors.lastname: Meier
authors.forename: Christian G
authors.initials: CG
authors.lastname: Schroer
authors.forename: Eric
authors.initials: E
authors.lastname: Galtier
authors.forename: Bob
authors.initials: B
authors.lastname: Nagler
authors.forename: Hae Ja
authors.initials: HJ
authors.lastname: Lee
authors.forename: Ulrich
authors.initials: U
authors.lastname: Vogt
mesh_terms: D000465:Algorithms; D004583:Electrons; D019544:Equipment Failure Analysis / Q000295:instrumentation* / Q000379:methods; D007834:Lasers; D007909:Lenses; D008027:Light; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012542:Scattering, Radiation; D014965:X-Rays