Resonance-enhanced x-ray multiple ionization of heavy atoms at LCLS

Benedikt Rudek, Daniel Rolles, Artem Rudenko, Sang-Kil Son, Lutz Foucar, Benjamin Erk, Sascha Epp, Ilme Schlichting, Lothar Strüder, Robin Santra, Joachim Ullrich, and the CAMP collaboration

[BibTeX]http://www.dpg-verhandlungen.de/year/2012/conference/stuttgart/part/a/session/11/contribution/5

The interaction of ultra-intense X-rays with rare gas atoms was studied at LCLS, where series of inner shell ionizations yield unprecedentedly high charge states within a single shot. Xenon, in particular, was ionized up to 36+, which requires ionization energies far exceeding the photon energy. Combined experimental and theoretical analysis of ion charge state distributions and simultaneously recorded fluorescence spectra showed that resonant excitations are responsibele for the enhanced ionization. This resonantly enhanced X-ray multi-ionization process (REXMI) is predicted to boost ionization in certain ranges of photon energy and thus enhance radiation damage in the vicinity of heavy atoms.