Hannover 2010 – wissenschaftliches Programm
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SYDI: Symposium Diffractive Imaging
SYDI 2: Diffractive Imaging of complex molecules in the gas-phase
SYDI 2.3: Hauptvortrag
Freitag, 12. März 2010, 15:00–15:30, E 415
Imaging Molecules from Within: Ultra-fast Structure Determination of Molecules via Photoelectron Holography with Free Electron Lasers. — •Joachim Ullrich1,2, Faton Krasniqi2, Bennaeur Najjari1, Alexander Voitkiv1, Sascha Epp2, Daniel Rolles2, Artem Rudenko2, and Lothar Strüder3 — 1Max-Planck-Institut für Kernphysik, Heidelberg, Germany — 2Max Planck Advanced Study Group, Center for Free Electron Laser Science, Hamburg, Germany — 3MPI Halbleiterlabor, München
A new scheme is suggested based on (i) brilliant X-ray Free Electron Laser sources, (ii) novel energy and angular dispersive, large-area electron imagers and (iii) the well-known photoelectron holography that shall provide time-dependent three-dimensional structure determination of small to medium sized molecules with sub-Angström spatial and femtosecond time resolution. Inducing molecular dynamics, i.e. wave-packet motion, dissociation, passage through conical intersections or isomerization, by a pump pulse this motion is visualized by the X-ray - laser probe pulse launching keV photoelectrons within few femtoseconds from specific and well-defined sites, deep core levels of individual atoms, inside the molecule. On their way out the photoelectrons are diffracted generating a hologram on the detector that encodes the molecular structure at the instant of photoionization, thus providing femtosecond snapshot images of the molecule from within. The technology allows obtaining time-dependent structure information for classes of samples not accessible otherwise such as aligned, oriented or conformer selected molecules or ultra-cold ensembles.