Single Shot Spatial and Temporal Coherence Properties of the SLAC Linac Coherent Light Source in the Hard X-Ray Regime

C. Gutt, P. Wochner, B. Fischer, H. Conrad, M. Castro-Colin, S. Lee, F. Lehmkühler, I. Steinke, M. Sprung, W. Roseker, D. Zhu, H. Lemke, S. Bogle, P. H. Fuoss, G. B. Stephenson, M. Cammarata, D. M. Fritz, A. Robert, and G. Grübel

Phys. Rev. Lett. 108, 024801 – Published 11 January 2012

Abstract

We measured the transverse and longitudinal coherence properties of the Linac Coherent Light Source (LCLS) at SLAC in the hard x-ray regime at 9 keV photon energy on a single shot basis. Speckle patterns recorded in the forward direction from colloidal nanoparticles yielded the transverse coherence properties of the focused LCLS beam. Speckle patterns from a gold nanopowder recorded with atomic resolution allowed us to measure the shot-to-shot variations of the spectral properties of the x-ray beam. The focused beam is in the transverse direction fully coherent with a mode number close to 1. The average number of longitudinal modes behind the Si(111) monochromator is about 14.5 and the average coherence time $τ_{c} = (2.0 \pm 1.0) fs$ . The data suggest a mean x-ray pulse duration of $(29 \pm 14) fs$ behind the monochromator for $(100 \pm 14) fs$ long electron pulses.

Received 20 September 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.024801

Authors & Affiliations

C. Gutt^1,*, P. Wochner², B. Fischer¹, H. Conrad¹, M. Castro-Colin², S. Lee^1,3, F. Lehmkühler¹, I. Steinke¹, M. Sprung¹, W. Roseker¹, D. Zhu³, H. Lemke³, S. Bogle², P. H. Fuoss⁴, G. B. Stephenson⁴, M. Cammarata³, D. M. Fritz³, A. Robert³, and G. Grübel¹

¹Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, D-22607 Hamburg, Germany
²Max-Planck-Institut für Intelligente Systeme, Heisenberg Straße 3, D-70569 Stuttgart, Germany
³LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
⁴Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 USA