title: Coherence and wavefront characterization of Si-111 monochromators using double-grating interferometry.
abstract: A study of the coherence and wavefront properties of a pseudo-channel-cut monochromator in comparison with a double-crystal monochromator is presented. Using a double-grating interferometer designed for the hard X-ray regime, the complex coherence factor was measured and the wavefront distortions at the sample position were analyzed. A transverse coherence length was found in the vertical direction that was a factor of two larger for the channel-cut monochromator owing to its higher mechanical stability. The wavefront distortions after different optical elements in the beam, such as monochromators and mirrors, were also quantified. This work is particularly relevant for coherent diffraction imaging experiments with synchrotron sources.
authors.affiliation: European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, Grenoble Cedex, France. ana.diaz@psi.ch
authors.forename: Ana
authors.initials: A
authors.lastname: Diaz
authors.forename: Cristian
authors.initials: C
authors.lastname: Mocuta
authors.forename: Julian
authors.initials: J
authors.lastname: Stangl
authors.forename: Mario
authors.initials: M
authors.lastname: Keplinger
authors.forename: Timm
authors.initials: T
authors.lastname: Weitkamp
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
authors.forename: Christian
authors.initials: C
authors.lastname: David
authors.forename: Till H
authors.initials: TH
authors.lastname: Metzger
authors.forename: Günther
authors.initials: G
authors.lastname: Bauer