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Dynamical diffraction effects in thin single crystals produce highly monochromatic parallel x-ray beams with a mutual separation of a few microns and a time delay of a few femtoseconds-the so-called echoes. This ultrafast diffraction effect is used at X-Ray Free Electron Lasers in self-seeding schemes to improve beam monochromaticity. Here, we present a coherent x-ray imaging measurement of echoes from Si crystals and demonstrate that a small surface strain can be used to tune their temporal delay. These results represent a first step toward the ambitious goal of strain tailoring new x-ray optics and, conversely, open up the possibility of using ultrafast dynamical diffraction effects to study strain in materials.

This work is an overview of the multi-modal hard X-ray nanoprobe beamline at the MAX IV Laboratory. The beamline provides an intense and coherent beam, focused to 40–200 nm in the energy range 5–28 eV., NanoMAX is the first hard X-ray nanoprobe beamline at the MAX IV laboratory. It utilizes the unique properties of the world’s first operational multi-bend achromat storage ring to provide an intense and coherent focused beam for experiments with several methods. In this paper we present the beamline optics design in detail, show the performance figures, and give an overview of the surrounding infrastructure and the operational diffraction endstation.

Strain and defects in crystalline materials are responsible for the distinct mechanical, electric, and magnetic properties of a desired material, making their study an essential task in material characterization, fabrication, and design. Existing techniques for the visualization of strain fields, such as transmission electron microscopy and diffraction, are destructive and limited to thin slices of the materials. On the other hand, nondestructive x-ray imaging methods either have a reduced resolution or are not robust enough for a broad range of applications. Here we present x-ray ptychographic topography, a method for strain imaging, and demonstrate its use on an InSb micropillar after microcompression, where the strained region is visualized with a spatial resolution of 30 nm. Thereby, x-ray ptychographic topography proves itself as a robust nondestructive approach for the imaging of strain fields within bulk crystalline specimens with a spatial resolution of a few tens of nanometers., Physical Review B, 103 (14), ISSN:1098-0121, ISSN:0163-1829, ISSN:1550-235X, ISSN:0556-2805, ISSN:2469-9969, ISSN:1095-3795, ISSN:2469-9950

Single crystal based optics is widely used at X-ray Free-Electron Laser (XFEL) facilities for beam tailoring. Here, we present recent developments in simulations of coherent X-ray wavefront propagation through crystals. In particular, the Laue case of dynamical diffraction has been implemented in Synchrotron Radiation Work- shop (SRW). Various effects due to wavefront transformation of short XFEL pulses have been simulated in the WavePropaGator (WPG) framework. Possible experimental observations of the effects are discussed.

The emergence of new high brilliance and high coherence facilities such as X-ray Free Electron Lasers (XFELs) and 4th generation synchrotrons open a new era in X-ray optics. Dynamical diffraction effects before disregarded are starting to play a role in the beam control of large scale facilities. In the case of XFEL facilities the temporal characteristics of the dynamical diffraction by thin perfect crystals can be used as a tool to generate femtosecond monochromatic pulses, in the case of self-seeding in the hard X-ray regime, but could even be used as method to characterize materials in this temporal range. In this contribution we present the first steps in the understanding of the spatial-displacement dependence of forward beams diffracted by thin crystals. The data collected by this technique is compared with crystal models based in dynamical diffraction theory. This type of study could open a new field to understand low strain materials in the femtosecond regime.

The photoinduced dynamics of ferric Cytochrome c was investigated by ultrafast non-resonant X-ray emission (XES) and X-Ray Absorption (XAS) spectroscopies, and a cascade through high spin states accompanied by heme doming are observed for the first time.

Time-resolved X-ray methods are widely used for monitoring transient intermediates over the course of photochemical reactions. Ultrafast X-ray absorption and emission spectroscopies as well as elastic X-ray scattering deliver detailed electronic and structural information on chemical dynamics in the solution phase. In this work, we describe the opportunities at the Femtosecond X-ray Experiments (FXE) instrument of European XFEL. Guided by the idea of combining spectroscopic and scattering techniques in one experiment, the FXE instrument has completed the initial commissioning phase for most of its components and performed first successful experiments within the baseline capabilities. This is demonstrated by its currently 115 fs (FWHM) temporal resolution to acquire ultrafast X-ray emission spectra by simultaneously recording iron Kα and Kβ lines, next to wide angle X-ray scattering patterns on a photoexcited aqueous solution of [Fe(bpy)3]2+, a transition metal model compound.