Wykład zatytułowany X-ray Free Electron Lasers – novel applications in Material Sciences wygłosi dr hab. inż. Ryszard Sobierajski, prof. PAN z Instytutu Fizyki PAN w Warszawie.
X-ray Free Electron Lasers (XFELs) are sources of femtosecond, intense, polarised, spatially coherent X- pulses. They open new research possibilities in many scientific areas, particularly Material Sciences. It is because they enable to study of both atomic and electronic properties of materials at ultrashort time scales at which these systems change. The presentation will start with a description of the main properties of the XFEL radiation, in comparison to the standard synchrotron X-ray radiation and optical laser pulses. Next selected applications of the XFEL radiation in natural sciences will be discussed – determining bio-molecule structures, watching ultrafast energy transfers within molecules, probing the characteristics of extreme states of matter, and studying ultrafast structural transitions in condensed matter. It will be followed by examples of own work at the European XFEL in Hamburg related to structural transformation – melting and recrystallization – in rapidly heated (~10^15 K/s) and cooled (~10^12 K/s) iron. The studied processes occur in highly non-equilibrium conditions – strongly superheated solid and deeply supercooled liquid states, respectively – where phase transformations occur extremely fast – at time scales of sub-ps and sun-ns – and may be limited by their kinetics. Finally, new possibilities for support in the XFEL research in the frame of recently acquired support from the Ministry of Education and Science will be presented.