Author: Rutishauser, S.
Paper Title Page
Grating Interferometry Applied to X-ray Wavefront Metrology at the SACLA  
  • Y. Kayser, Ch. David, U. Flechsig, S. Rutishauser
    PSI, Villigen PSI, Switzerland
  • T.K. Kameshima, T. Katayama
    JASRI/SPring-8, Hyogo, Japan
  • H. Ohashi
    Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Hyogo, Japan
  • M. Yabashi
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  Grating interferometry allows for spatially resolved studies of the local wavefront propagation direction with an angular sensitivity of tens of nanoradian. In this perspective the grating interferometry technique has found application in the metrology of X-ray optics at synchrotron facilities and was moreover used for the investigation of the X-ray wavefront properties at the LCLS(*). At the SACLA grating interferometry was applied to two different types of experiments. A first application was the study the wavefront preservation capabilities of the X-ray optics installed upstream of the end station of beam line 3 (two off-set mirror systems and a double crystal monochromator). The experimental results confirmed the excellent quality of the optical components and demonstrated the sensitivity of grating interferometry. In a second application the source point position was determined as the XFEL was driven into saturation. Grating interferometry permits, thus, to get a better understanding of the XFEL machine.
(*) S. Rutishauser, L. Samoylova, J. Krzywinski, et al., “Exploring the wavefront of hard X-ray free-electron laser radiation,” Nat. Commun. 3, 947 (2012).