Darmstadt 2008 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 11: Posters: Interaction with attosecond and VUV-light
A 11.2: Poster
Dienstag, 11. März 2008, 16:30–18:30, Poster C3
Pump-probe experiments combining an attosecond beamline with a reaction microscope — •Helga Rietz, Konstantinos Simeonidis, Ram Gopal, and Joachim Ullrich — Max-Planck-Institut für Kernphysik, 69117 Heidelberg
The rapid development of femtosecond lasers over the last decade has enabled the investigation of nuclear dynamics in molecules in unprecedented detail. Recently, laser pulses of only 7 fs combined with advanced multi-particle momentum imaging spectrometers, so-called reaction microscopes, lead to the direct observation of the vibration of H2 and D2 molecules. However, electronic motion in atoms or molecules occurs on timescales of tens to hundreds of attoseconds and is thus not accessible with conventional ultra-fast laser technology, where the lasers’ wavelength limits the pulse length to about 4 fs. Therefore we use high harmonic generation (HHG), which provides an efficient way to produce attosecond pulses.
Here we present the setup of a new experiment which combines an HHG light source with a reaction microscope. The light-source is based on a commercially available femtosecond laser system, delivering pulses with a length of 25 fs. Further compression to below 6 fs is achieved via filamentation. In order to guarantee highest stability and, at the same time enable utmost flexibility, the whole HHG setup is housed in one single vacuum chamber containing all necessary optics, a gas target for HHG and an XUV-spectrometer. In a first experiment we plan to characterize the attosecond pulses by 4π-detection of the photoelectrons in single ionization of helium.