title: Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.
abstract: X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space-time modulation of an X-ray beam.
authors.affiliation: Helmholtz Zentrum Berlin für Materialien und Energie, Germany; Freie Universität Berlin, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Vadilonga
authors.affiliation: Helmholtz Zentrum Berlin für Materialien und Energie, Germany.
authors.forename: Ivo
authors.initials: I
authors.lastname: Zizak
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Moscow, Russian Federation.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Roshchupkin
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Moscow, Russian Federation.
authors.forename: Emelin
authors.initials: E
authors.lastname: Evgenii
authors.affiliation: Helmholtz Zentrum Berlin für Materialien und Energie, Germany; Freie Universität Berlin, Germany.
authors.forename: Andrei
authors.initials: A
authors.lastname: Petsiuk
authors.affiliation: Universität Potsdam, Potsdam - Golm, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Leitenberger
authors.affiliation: Helmholtz Zentrum Berlin für Materialien und Energie, Germany; Freie Universität Berlin, Germany.
authors.forename: Alexei
authors.initials: A
authors.lastname: Erko
keywords: optics; sagittal X-ray diffraction; surface acoustic waves; synchrotron radiation