Development of X-ray Spectroscopies and Radiochemical Applications

Objectives

We are developing X-ray spectroscopies to address various questions in radiochemistry and the fields of intermediate nuclear waste storage and disposal research. For example, we (1) conduct geochemical investigations to gain an in-depth understanding of radionuclide migration mechanisms, (2) explore radionuclides and develop generators for radiopharmaceutical applications, and (3) study the mechanisms of lanthanide and actinide toxicology in mammalian cells.
Current Research Topics

Fundamental studies:

  • Development and applications of X-ray spectroscopic tools to probe bonding properties of actinides and lanthanides
  • Relations between stability - structural properties of f-elements
  • Magnetic properties of lanthanide compounds

Applied studies:

  • Mechanistic understanding of interaction mechanisms of radionuclides in the geosphere
  • Structural properties of spent nuclear fuel (SNF)
  • Toxicological investigations with a focus on actinide and lanthanide homeostasis in mammalian cells
  • Radiopharmaceutical research focusing on the development of radionuclide generators, as well as understanding bonding properties and stabilization mechanisms of radiopharmaceuticals
Instruments

Our studies utilize high-energy resolution X-ray absorption near-edge structure (HR-XANES), X-ray emission spectroscopy (XES), and resonant inelastic X-ray scattering (RIXS) techniques to study the structural properties of actinide (An) elements. The latest upgrade to our NEXT-generation multi-analyzer Johann-type X-ray emission spectrometer (NEXT spectrometer, see the Fig.1) features a rotational table, enabling experiments at 1 m, 0.5 m, 90°, and in backscattering geometry. This is the central instrument at the ACT station for actinide research at the CAT-ACT beamline of the KIT Light Source in Karlsruhe, Germany.

 

Our setup is optimized for An M4,5-edge HR-XANES and XES/RIXS experiments; absorption of 3–4 keV photons by air is minimized by a helium environment enclosing the sample, crystals, and detector, thereby enhancing efficiency. This instrument, combined with access to the controlled area laboratory at INE in close proximity, is globally unique, enabling An M4,5-edge HR-XANES and XES/RIXS investigations of solid and liquid-phase radioactive materials, including those under extreme conditions. For example, in situ/in operando spectroscopy of solid and liquid actinide compounds can be performed.
Latest Developments
Np M5-edge HR-XANES spectra of 83 or 1 ppm Np sorbed on the clay mineral illite. The newly installed cryostat, which can be used down to an incident X-ray energy of 3 keV, is also shown.

 

 

Artist’s concept of the RIXS signal of a Pu sample including the satellite peak, a tool that can be utilized to determine the number of 5f valence electrons as well as bond covalency.

https://www.nature.com/articles/s41467-024-54574-7

 

 

3D view of the NEXT spectrometer enabling experiments at 1 m, 0.5 m, 90°, and in backscattering geometry with He filled glove box around it. KIT-IBG
3D view of the NEXT spectrometer enabling experiments at 1 m, 0.5 m, 90°, and in backscattering geometry with He filled glove box around it.

Contact :

 

 

Junior group head Dr. Bianca Schacherl     

    +49 721 608 28754