Project title: Resonant Soft X-ray Scattering Applied to Atoms and Molecules
Main applicant: Jan-Erik Rubensson, Division of X-ray Photon Science
Grant amount: 4 000 000 SEK for the period 2022-2025
Resonant Inelastic Soft X-ray Scattering (RIXS) spectroscopy and related experimental methods are applied to atoms, molecules, liquids and molecular materials. The most important assets of the RIXS process are Ångström-scale site-specificity, access to the femtosecond time scale, and the symmetry selectivity imposed by the dipole approximation. Two new RIXS facilities are about to come into operation: First, the VERITAS endstation at the MAX IV laboratory uses the outstanding brilliance of the diffraction-limited 3-GeV storage ring to refine the RIXS technique, especially concerning energy resolution. Second, a 1D imaging spectrometer installed as a Swedish in-kind contribution at the European XFEL will allow for non-linear and time-resolved X-ray spectroscopy.
These facilities promise access to interactions that have hitherto been hidden to X-ray methodology. In this project we will use the new opportunities to gain information about the evolution of the molecular electronic-vibronic wavefunctions. The role of spin-orbit coupling, electronic-vibronic coupling and decoherence during the development of wavefunctions far from equilibrium, close to barriers and conical intersections will be addressed in a unique way. Dynamics is influenced and controlled in femtosecond pump-probe experiments. The short intense XFEL pulses let us aim for techniques based on the stimulated RIXS process with the goal to establish coherent methods in the X-ray range.
