Kiyoshi Ueda

TL;DR: In this article, the authors reported an unprecedented high degree of ionization of xenon atoms by 1.5 keV free-electron laser pulses to charge states with ionization energies far exceeding the photon energy.

TL;DR: This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime and provides newcomers to the area with insights into: the basic physics of FELs, the qualities of the radiation they produce, the challenges of transmitting that radiation to end users and the diversity of current scientific applications.

TL;DR: The observation of DCH states, which exhibit a unique signature, and agreement with theory proves the feasibility of double-core-hole spectroscopy, and exploit the ultrashort pulse duration of the free-electron laser to eject two core electrons on a time scale comparable to that of Auger decay and demonstrate possible future X-ray control of physical inner-shell processes.

TL;DR: The experimental and modelling results establish that the ionization of a molecule is considerably enhanced compared to that of an individual heavy atom with the same absorption cross-section, and demonstrate that efficient modelling of X-ray-driven processes in complex systems at ultrahigh intensities is feasible.