The group ‘in-situ spectroscopy for Environmental Science’ operates the PHOENIX (PHotons for the Exploration of Nature by Imaging and XAFS) beamline. PHOENIX is one of the few undulator beamlines worldwide, which offer x-ray microspectroscopy for both soft x-rays and the rarely served tender energy range. The scientific goal of the beamline is the in situ characterization of crystalline and amorphous materials in terms of morphology, atomic composition, local order, ligand coordination, and electronic structure at different time and length scales ranging from a few mm to a few micrometer. The energy range ($0.3-8$~keV) covers the K-absorption edges of low Z-elements (O to Fe) and important L-edges (Ca to La), which places the PHOENIX team in a unique position to address important questions related to environmental science, catalysis, energy research, earth science, biology, geochemistry and the design of new functional materials. As undulator beamline PHOENIX offers flux-hungry techniques, in particular x-ray absorption and emission microspectroscopy (XAS and XES), for dilute systems as well as scanning fluorescence microscopy with 3 micron spatial resolution.
A major part of the activities of the PHOENIX team are devoted to instrumental developments, most notably the implementation of emission spectroscopy for the tender X-ray range with a new von Hamos spectrometer. Furthermore, in a collaborative effort with Dr. G. Smolentsev, novel pump and probe schemes for tender X-rays are currently under development and this experiment is currently open for first experienced users for pilot experiments. Duetto and IDOL lasers Duetto and IDOL lasers are available for photoexitation.
The group also develops microfluidic devices for the energy range available at PHOENIX, enabling transmission and fluorescence type XAS measurements for in-house and user experiments. The devices have flexible design for studying single or multiple reactant solutions, offering precise control, rapid mixing and the possibility to transpose a chemical reaction onto spatial coordinates.
The group's own research program aims to study in situ processes relevant to environmental sciences and energy research. Currently, our research aims to study the first steps of crystallization processes using liquid cells and a liquid microjet technique.