title: In situ flame chemistry tracing by imaging photoelectron photoion coincidence spectroscopy.
abstract: Adaptation of a low-pressure flat flame burner with a flame-sampling interface to the imaging photoelectron photoion coincidence spectrometer (iPEPICO) of the VUV beamline at the Swiss Light Source is presented. The combination of molecular-beam mass spectrometry and iPEPICO provides a new powerful analytical tool for the detailed investigation of reaction networks in flames. First results demonstrate the applicability of the new instrument to comprehensive flame diagnostics and the potentially high impact for reaction mechanism development for conventional and alternative fuels. Isomer specific identification of stable and radical flame species is demonstrated with unrivaled precision. Radical detection and identification is achieved for the initial H-abstraction products of fuel molecules as well as for the reaction controlling H, O, and OH radicals. Furthermore, quantitative evaluation of changing species concentrations during the combustion process and the applicability of respective results for kinetic model validation are demonstrated. Utilization of mass-selected threshold photoelectron spectra is shown to ensure precise signal assignment and highly reliable spatial profiles.
authors.affiliation: German Aerospace Center (DLR) - Institute of Combustion Technology, Stuttgart 70569, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Osswald
authors.affiliation: Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Hemberger
authors.affiliation: Mass Spectrometry in Reactive Flows - Thermodynamics (IVG), University of Duisburg-Essen, Duisburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Bierkandt
authors.affiliation: Mass Spectrometry in Reactive Flows - Thermodynamics (IVG), University of Duisburg-Essen, Duisburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Akyildiz
authors.affiliation: German Aerospace Center (DLR) - Institute of Combustion Technology, Stuttgart 70569, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Köhler
authors.affiliation: Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Bodi
authors.affiliation: Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Gerber
authors.affiliation: Mass Spectrometry in Reactive Flows - Thermodynamics (IVG), University of Duisburg-Essen, Duisburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Kasper