Femtosecond response of atoms and molecules to ultra-intense hard x-rays

Sang-Kil Son

[BibTeX]https://indico.desy.de/indico/event/22086/

X-ray free-electron lasers (XFELs), featuring ultra-intense and ultrafast x-ray pulses, enable the investigation of the structure and dynamics of matter under extreme conditions. Understanding how atoms and molecules interact with intense x-ray pulses is fundamental and crucial for interpreting and designing XFEL-driven experiments. An accurate description of the interaction, however, poses a great challenge because of extremely complicated processes involved in their dynamics. To address this challenge, we have developed dedicated theoretical tools, XATOM and XMOLECULE, and employed them to investigate recent experiments of xenon atoms and iodomethane molecules. Our joint theoretical and experimental studies show that multiphoton multiple ionization of atoms and molecules during intense hard x-ray pulses is much enhanced and by far different from the prediction based on x-ray absorption cross section, and explain the ionization enhancement mechanism. Our work clearly demonstrates the predictive power of our modeling, providing a key insight of the XFEL-matter interaction and a basis to advance new frontiers of XFEL science.

Tags: XATOM, XMOLECULE, CFEL, DESY