Seminars Archive

Warm Dense Matter and Material Dynamics Experiments on SHort Pulse Light Sources

Abstract
Recent advances in the production of XUV radiation have led to the development of ’4th generation’ light sources with spectral brightness ten orders of magnitude greater than existing synchrotrons. These short pulse light sources offer a unique way of depositing energy into materials and to create states of strong electronic excitation and high temperature and pressure. When focused to micron-scale spots these sources produce intensities greater than 10^16 W cm^−2 - a regime previously confined to experiments with optical lasers. We demonstrate that at these intensities the interaction of XUV radiation with matter radically changes since the photon flux is sufficiently high to eject the majority of bound electrons responsible for the initial absorption. Our experiments show a change in transmission of an aluminum foil from 15% to 65% within tens of femtosec-onds, a time much shorter than expected electron-phonon coupling times, thus resulting in a novel transient state of highly-ionized, yet crystalline matter. Future experimental efforts will be outlined.