title: Single shot speckle and coherence analysis of the hard X-ray free electron laser LCLS.
abstract: The single shot based coherence properties of hard x-ray pulses from the Linac Coherent Light Source (LCLS) were measured by analyzing coherent diffraction patterns from nano-particles and gold nanopowder. The intensity histogram of the small angle x-ray scattering ring from nano-particles reveals the fully transversely coherent nature of the LCLS beam with a number of transverse mode 〈Ms〉 = 1.1. On the other hand, the speckle contrasts measured at a large wavevector yields information about the longitudinal coherence of the LCLS radiation after a silicon (111) monochromator. The quantitative agreement between our data and the simulation confirms a mean coherence time of 2.2 fs and a x-ray pulse duration of 29 fs. Finally the observed reduction of the speckle contrast generated by x-rays with pulse duration longer than 30 fs indicates ultrafast dynamics taking place at an atomic length scale prior to the permanent sample damage.
authors.forename: Sooheyong
authors.initials: S
authors.lastname: Lee
authors.forename: W
authors.initials: W
authors.lastname: Roseker
authors.forename: C
authors.initials: C
authors.lastname: Gutt
authors.forename: B
authors.initials: B
authors.lastname: Fischer
authors.forename: H
authors.initials: H
authors.lastname: Conrad
authors.forename: F
authors.initials: F
authors.lastname: Lehmkühler
authors.forename: I
authors.initials: I
authors.lastname: Steinke
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.forename: H
authors.initials: H
authors.lastname: Lemke
authors.forename: M
authors.initials: M
authors.lastname: Cammarata
authors.forename: D M
authors.initials: DM
authors.lastname: Fritz
authors.forename: P
authors.initials: P
authors.lastname: Wochner
authors.forename: M
authors.initials: M
authors.lastname: Castro-Colin
authors.forename: S O
authors.initials: SO
authors.lastname: Hruszkewycz
authors.forename: P H
authors.initials: PH
authors.lastname: Fuoss
authors.forename: G B
authors.initials: GB
authors.lastname: Stephenson
authors.forename: G
authors.initials: G
authors.lastname: Grübel
authors.forename: A
authors.initials: A
authors.lastname: Robert