Visualizing Chemistry with X-Rays – Prospects of high resolution and high intensity X-ray scattering

by Simon Schreck (Molecular Physics Division)

Monday 14 Sept 2015, 10:00 → 11:00 Europe/Stockholm

FB 55

The potential energy surface is a central and powerful concept in physics, chemistry and materials science and is sometimes termed as the ‘keystone to the visualization of chemical processes’. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. I will demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution can be utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. I will show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The instrumental developments in high-resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach in the near future. At the same time the ultrahigh peak brilliance available at X-ray free-electron lasers opens the possibility to transfer nonlinear spectroscopic techniques from the optical and infrared into the X-ray regime. I will discuss the prospects of stimulated resonant X-ray scattering in particular utilizing multi-pulse multi-color femtosecond x-rays. Furthermore I will show first results from single-pulse experiments and discuss the crucial experimental parameters in the regime of non-linear X-ray-matter interactions.