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Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 04/05 Podcast
Atomic and molecular ionization dynamics in strong IR and XUV fields probed by time-resolved coincidence spectroscopy

Atomic and molecular ionization dynamics in strong IR and XUV fields probed by time-resolved coincidence spectroscopy

Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 04/05 vor 14 Jahren

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In the work for this thesis, a split-mirror-setup was designed and
build, which was used to split the XUV laser-pulse of FELs (Free
Electron Laser) into two identical pulses from which one can be
delayed. With this setup the laser pulses of FLASH, Hamburg and
SCSS, Harima(Japan) where characterized temporally, to determine
the temporal pulse-structure for subsequent experiments. The
intermolecular dynamics of the homonuclear diatomic molecules
nitrogen and oxygen were examined and the experimental results were
reproduced by classical simulations. In the measurement with oxygen
for an energy band of the coincident singly charged ions, an
ionization probability was found that depends on the delay between
the two XUV-pulses. This can most probably be explained by the
autoionization of an excited singly charged molecular state.
Subsequently the investigation of the two photon double ionization
(TPDI) of deuterium is presented. In the single pulse experiments
simulations within the Born-Oppenheimer approximation made it
possible to distinguish between the direct and sequential TPDI. In
the pump-probe experiments light was shed onto the dynamics of the
TPDI. In addition, experiments with strong few-cycle near-infrared
(NIR) pulses are presented that examined the carrier envelope phase
(CEP) dependence of the non-sequential double ionization of argon.
Implementing single-shot CEP-tagging in conjunction with
coincidence spectroscopy allowed to achieve unprecedented accuracy
in measuring correlated electron dynamics.