Physics with Synchrotron Radiation

The activities of the subgroup Physics with Synchrotron Radiation focus on investigations of fundamental photoionization processes induced by short wavelength synchrotron and free electron laser radiation from the vacuum ultraviolet down to the x-ray range. Scientific questions to be answered here are how quantum mechanical interference effects and electron correlations (Interactions between electrons in atoms, molecules, clusters, and liquids) do modify photoionization probabilities upon interaction with one or more photons.

 

In particular, we currently investigate how quantum mechanical entanglement between atoms and molecules and their constituents in weakly bound clusters and liquids determines relaxation and charge transfer processes, hitherto unknown. These recently discovered processes are discussed as a missing link to understanding the processes induced by ionizing radiation on the human body and as possible mechanisms relevant to astrochemistry on dust and icy grains. Another scientific focus is the investigation of molecular chirality by photoelectron circular dichroism, exploiting the asymmetric scattering of photoelectrons during their way out at the nuclear backbone of a chiral molecule. Here we use the possibility to atomic-site selectively emit photoelectrons by addressing specific photoionization thresholds and resonances. The corresponding enabling experimental stations are developed in our group and are used at the synchrotron and free electron laser facilities in Berlin and Hamburg and at the facility for antihydrogen and ion research (FAIR) in Darmstadt.

Methods

  • High-resolution UV/Vis fluorescence spectroscopy
  • Electron spectroscopy
  • Multi-Electron und Electron-Photon coincidence spectroscopy