Wojciech Roseker

TL;DR: A prototype device capable of splitting an x-rays pulse into two adjustable fractions, delaying one of them with the aim to perform x-ray photon correlation spectroscopy and pump-probe type studies, was designed, manufactured, and tested.

TL;DR: The achieved contrast values of 56% indicate a feasibility of performing coherence-based experiments with the delay line with the aim of performing split pulse X-ray photon correlation spectroscopy and pump–probe type studies.

TL;DR: Water dynamics at sub-100 fs is measured and it is shown that it cannot be described by simple thermal motion due to the build-up of tetrahedral structures upon supercooling, and cage effects play an important role even on timescales over 25 fs due to hydrogen-bonding.

TL;DR: A comprehensive joint experimental-theoretical study of the equilibrium pair-structure and short-time diffusion in aqueous suspensions of highly charged poly-acrylate (PA) spheres in the colloidal fluid phase is reported.

TL;DR: The coherence properties of the free-electron laser SACLA are measured on a single shot basis at an X-ray energy of 8 keV by analysing small-angle X-rays scattering speckle patterns from colloidal dispersions and developing a simulation model to determine the degree of coherence from intensity histograms.