Project Details
Projekt
X-ray spectroscopy with high temporal and spatial resolution
Applicant
Professor Dr. Christian Spielmann
Subject Area
Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
Term
from 2002 to 2009
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5373687
Studying structure and dynamics on an atomic scale is indispensable for a deeper understanding of several processes in physics, chemistry and biology. Due to their short wavelength x-rays are ideally suited to gain structural information. The natural time scale of atomic motion is the femtosecond region (1 fs = 10-15) not accessible with conventional x-ray sources. In the last few years we have witnessed a tremendous progress in laser technology. Nowadays, ultrashort pulses from compact table top laser systems can be converted in x-ray pulses by nonlinear interactions. With high harmonic generation ultrashort laser pulses at 800 nm have been converted into spatially coherent soft x-ray pulses down to 3 nm. The major objectives of this project are the set up of a soft x-ray source based on high harmonic generation, and he demonstration of its feasability for time resolved x-ray spectroscopy. With soft x-ray radiation ultrafast time-resolved experiments are now feasible, in which the atomic motion in molecular systems can not only be studied in real-time but also be controlled on that time scale. This of course also allows to spatially characterize complex molecules in the liquid phase. Time-resolved soft x-ray diffraction opens up a wide range of new condensed phase studies such as for instance structural changes of photoexcited molecules in chemical reactions, energy transfer in electron-photon surface interactions, details of acoustic and optical phonon dynamics. Adaptive shaping of phase, amplitude and polarization state of femtosecond laser pulses is a new tool to control complex dynamics (phonon modes, chemical reactions) in the condensed phase. This recently developed technique is expected to have a major impact in the broad applications of ultrafast soft x-ray spectroscopy.
DFG Programme
Priority Programmes
