Hannover 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 43: Poster II
Q 43.27: Poster
Mittwoch, 20. März 2013, 16:00–18:30, Empore Lichthof
An x-ray split and delay-unit for the European XFEL — •Sebastian Roling1, Stefan Braun2, Peter Gawlitza2, Liubov Samoylova3, Björn Siemer1, Harald Sinn3, Frank Siewert4, Frank Wahlert1, Michael Wöstmann1, and Helmut Zacharias1 — 1Physikalisches Institut WWU Münster, Wilhelm-Klemm Straße 10, 48149 Münster — 2Fraunhofer Institut IWS, Winterbergstraße 28, 01277 Dresden — 3European XFEL GmbH, Alber-Einstein-Ring 19, 22761 — 4HZB, Albert-Einstein-Straße 15, 12489 Berlin
For the European XFEL an x-ray split- and delay-unit (SDU) is built covering photon energies from 5 keV up to 20 keV. This SDU will enable time-resolved x-ray pump / x-ray probe experiments as well as sequential diffractive imaging on a femtosecond to picosecond time scale. The set-up is based on geometric wavefront beam splitting. The x-ray FEL pulses will be split by a sharp edge of a silicon mirror coated with Mo/B4C multilayers for photon energies above 10 keV and W/B4C below 10 keV. Both partial beams will then pass variable delay lines. For different wavelengths the angle of incidence onto the multilayer mirrors will be adjusted in order to match the Bragg condition. At a photon energy of 20 keV the reflectance of a Mo/B4C multilayer coating with a multilayer period of 3.2 nm and N = 200 layers under a Bragg-angle of 0.57∘ amounts to R = 0.92. For a photon energy of 5 keV the reflectance of a W/B4C coating with a multilayer period of 4 nm is R = 0.73. Because of the different incidence angles, the path lengths of the beams will vary as a function of wavelength between ± 3.7 ps at 20 keV and up to ± 40 ps at 5 keV.