eprintid: 35166
rev_number: 15
eprint_status: archive
userid: 8318
dir: disk0/00/03/51/66
datestamp: 2024-07-26 06:30:50
lastmod: 2024-08-12 14:22:31
status_changed: 2024-07-26 06:30:50
type: doctoralThesis
metadata_visibility: show
creators_name: Magunia, Alexander
title: Time-and-Energy–Resolved Electron Dynamics in Atoms
and Molecules with Intense Short-Wavelength Light
subjects: ddc-530
divisions: i-130001
divisions: i-851340
adv_faculty: af-13
cterms_swd: Laser
cterms_swd: Molekülphysik
cterms_swd: Atomphysik
cterms_swd: Röntgenstrahlung
cterms_swd: Zeitauflösung
cterms_swd: Spektroskopie
cterms_swd: Quantenmechanik
abstract: This thesis investigates the interaction of ultrashort, extreme-ultraviolet (XUV) and
soft x-ray laser pulses with atoms and molecules in the gas phase. In total, the
subject is explored from four different perspectives, which are all based on the short-
lived–coherent electronic responses to the laser pulses, and measured with transient
absorption spectroscopy. First, a theoretical study reveals how transient energy shifts
of electronic dressed states in atoms driven by an intense XUV Free-Electron Laser
(FEL) lead to temporal dipole phase shifts and absorption-line changes. Second,
a follow-up study investigates the electronic-population Rabi-cycles corresponding
to the absorption-line changes of the first study. A convolutional neural network
is employed to reconstruct the temporal population dynamics from the simulated
spectral absorption modifications. The inversion from an absorption to an emission
line is described and a potential experimental demonstration in helium is discussed.
Third, dense gas targets enable amplification of the otherwise improbable, non-linear
process of stimulated resonant inelastic x-ray scattering (RIXS), as well as x-ray FEL
propagation-based spatial-spectral reshaping. To this end, a new experimental setup is
built and utilized in an x-ray FEL driven RIXS experiment in dense neon gas. Fourth,
a novel experiment combining XUV pulses from high-order harmonic generation
(HHG) and XUV-FEL pulses is demonstrated by time-resolving a photochemical
reaction in molecular oxygen. An FEL pulse initiates coupled nuclear-electronic
dissociation pathways from molecular oxygen ions, which are time-resolved on femto-
and picosecond time scales by identifying the reaction products in the time-delayed
HHG absorption spectra. A FEL-photon-energy–resolved study of the fragments
is performed to compare findings from absorption spectroscopy with kinetic energy
release spectra recorded in parallel with a reaction microscope.
date: 2024
id_scheme: DOI
id_number: 10.11588/heidok.00035166
ppn_swb: 1898136831
own_urn: urn:nbn:de:bsz:16-heidok-351662
date_accepted: 2024-07-19
advisor: HASH(0x55a9a64c6e18)
language: eng
bibsort: MAGUNIAALETIMEANDENE
full_text_status: public
place_of_pub: Heidelberg
citation:   Magunia, Alexander  (2024) Time-and-Energy–Resolved Electron Dynamics in Atoms and Molecules with Intense Short-Wavelength Light.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/35166/1/PhDthesisAlexanderMagunia.pdf