Author: Kameshima, T.K.
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).
TUC01 Hard X-ray Self-Seeding Setup and Results at SACLA 603
  • T. Inagaki, N. Adumi, T. Hara, T. Ishikawa, R. Kinjo, H. Maesaka, Y. Otake, H. Tanaka, T. Tanaka, K. Togawa, M. Yabashi
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • S. Goto, Y. Inubushi, T.K. Kameshima, T. Ohata, K. Tono
    JASRI/SPring-8, Hyogo, Japan
  • T. Hasegawa, S. Tanaka
    SES, Hyogo-pref., Japan
  • H. Kimura, A. Miura, H. Ohashi, H. Yamazaki
    Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Hyogo, Japan
  In order to improve the spectral and temporal properties of XFEL, the self-seeding option based on the transmission crystal optics has been implemented in SACLA since 2012. The self-seeding setup composed of four dipole magnets that can generate up to 50 fs temporal delay and a diamond single crystal with the thickness of 180 micro-m has been installed at the position of the 9th undulator segment, which has been moved downstream. In 2013, the installation of all the components has been completed in August and the commissioning has been started in October. After a number of tuning processes such as the beam collimation and undulator K-value optimization, significant spectral narrowing has been confirmed at 10 keV with the C(400) Bragg reflection. The spectral bandwidth of seeded FEL is about 3 eV, which is nearly one order narrower than that of SASE measured without the diamond crystal. The peak spectral intensity of seeded FEL is about 5 times higher than that of SASE. Systematic optimization on beam properties is now in progress towards experimental use of seeded XFELs. This talk gives the overview of the plan, achieved results and ongoing R&D.  
slides icon Slides TUC01 [20.337 MB]