title: Photoionization in strong laser fields:  from atoms to complex molecules
creator: Laux, Martin
subject: ddc-530
subject: 530 Physics
description: In this  thesis, the results of the strong-field photoionization of various gas targets, particularly  of methane are presented. The photoionization was performed by focusing an ultrashort  two-color laser pulse into the supersonic gas jet of a Reaction Microscope. The capability  of the Reaction Microscope of simultaneous detection and identification of all charged  ionization products enables the channel- and fragment-specific analysis of the ionization  process. The tunable relative phase between both components of the two-color field is  an additional control parameter for the experiment. The discrepancy in the yield of lowenergy  photoelectrons for methane ionization channels with a coincident molecular ion  on the one hand and a coincident atomic ion on the other hand resembles similar results  from experiments in molecular hydrogen, which could be explained by autoionization  and simultaneous vibrational relaxation of a molecular Rydberg state. Despite the lack of  reference data for Rydberg states of methane with excitations higher than n = 6, it was  possible to estimate their energies and for one ionization channel, it could be demonstrated  that electrons released by autoionization of Rydberg states between n = 9 and n = 12 are  the origin of the enhanced low-energy electron yield.
date: 2017
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/23688/1/Diss_MLaux_20171024.pdf
identifier: DOI:10.11588/heidok.00023688
identifier: urn:nbn:de:bsz:16-heidok-236882
identifier:   Laux, Martin  (2017) Photoionization in strong laser fields: from atoms to complex molecules.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/23688/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng