|Title:||Angular distributions and time ordering in double ionization of helium: approaching the long-wavelength regime||Other Titles:||Winkelverteilungen und Zeitordnung in Doppelionisation von Helium: Annäherung an das Regime der langen Wellenlängen||Language:||English||Authors:||Ederer, Manuel||Qualification level:||Diploma||Advisor:||Burgdörfer, Joachim||Assisting Advisor:||Donsa, Stefan||Issue Date:||2020||Number of Pages:||68||Qualification level:||Diploma||Abstract:||
With the progress in laser technologies over recent years it has become possible to create coherent and intense extreme ultraviolet (XUV) pulses via high-harmonic generation with durations of only a few femtoseconds or even reaching the attosecond regime. This development has started the field of attosecond science which has enabled detailed studies of electron dynamics with a time resolution down to single attoseconds. In order to ultimately be able to control electrons and their motion with all-optical devices, it is a necessity to fully understand the fundamentals of light-matter and electron-electron interaction on this time scale. Double ionization of helium provides the ideal testbed to obtain insights into the electron dynamics in the full three-body Coulomb break-up process, as the process is simple enough such that ab-initio computations are numerically feasible. While the two extremal cases of few-photon and strong-field double ionization have been studied extensively, the regime in between where 4 to 20 photons are needed to overcome the double ionization threshold of helium has not gained a lot of attention. The reason for this is the numerical complexity and experimental limitations to generate intense light pulses for < 400 nm. Within this thesis we aim at bridging this gap starting from one-photon double ionization, increasing successively the wavelength of the ionizing light field until we approach the experimentally strong-field regime. To do so we employ state of the art ab-initio simulations. To characterize the influence of electron-correlation onto the double ionization process, we study similarities and differences in the angular emission pattern over a broad range of wavelengths.
|Keywords:||Nichtlinear Optik; Quantenmechanik
Nonlinear Optics; Quantummechanics
|Library ID:||AC15568670||Organisation:||E136 - Institut für Theoretische Physik||Publication Type:||Thesis
|Appears in Collections:||Thesis|
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