Oliver Kugeler - Academia.edu (original) (raw)
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Papers by Oliver Kugeler
AIP Conference Proceedings, 2004
ABSTRACT We describe the construction and testing of a supersonic jet apparatus to carry out elec... more ABSTRACT We describe the construction and testing of a supersonic jet apparatus to carry out electron spectroscopy on Van-der-Waals clusters using Synchrotron Radiation as an excitation source. The cluster source works with a conical nozzle that can be cooled with LHe as well as with LN2. The system has been optimized for mechanical and thermal stability, for low residual magnetic fields and is of a compact design.
ABSTRACT Molecule frame electron angular distribution in the gas phase have attracted increasing ... more ABSTRACT Molecule frame electron angular distribution in the gas phase have attracted increasing interest during the last five years after the first of such distributions was measured [1]. The studies were extended over a variety of molecules and performed for core ionization as well as valence ionization [2, 3]. Experimentally such studies are measurements of vector correlations between the emission directions of electrons and fragment ions produced via the photoionization or -excitation process. The corresponding angular distribu-tions provide a wealth of information on the dynamics of molecular photoionization, in particular dipole transition matrix elements and their corresponding phases. Some of these experiments are expected to be sensitive to the coherence properties of the photoemission process in the case of homonuclear molecules, a problem closely related to the core-hole localization [4-6]. We have performed two types of experi-ments of this subject, one concerned with the ejection of a 1s photoelectron of N 2 in the vicinity of the σ shape resonance and the other exploring the Auger angular distributions after photoexcitation of N 2 to the π* resonance. Both experiments are intended to shed some light on the problem to which extend core holes in N 2 are localized or delocalized. The experiments were performed at beamline BW3 using an angle resolved fragment-ion-electron coincidence setup. This setup consists of a ion time-of-flight spectrometer having position sensitive anode combined with five independent electron time-of-flight spectrometers in order to allow for the angle resolved detection of both particles in coincidence [3].
The Journal of Physical Chemistry A, 2001
Review of Scientific Instruments, 2003
We have determined the transit time distribution of electrons passing a high resolution hemispher... more We have determined the transit time distribution of electrons passing a high resolution hemispherical energy analyzer. Comparison of our measured results with analytical expressions reveals that differing transit times between electrons of equal kinetic energy mainly build up on the Kepler-type orbits on which the electrons travel through the hemispheres. To facilitate the measurements, we have installed a position sensitive electron detector capable of single event detection into our spectrometer. This device is based on a delay-line anode. We briefly report on the energy resolution achieved in comparison with a slower readout system via a fluorescent screen. The transit time distribution is important in coincidence experiments, where electrons detected in the hemispherical analyzer are to be related to events in other detectors. We discuss the feasibility of electron–electron coincidence experiments using a hemispherical detector plus a time-of-flight drift tube for energy discrim...
Journal of Physics: Conference Series, 2012
Journal of Physics: Conference Series, 2009
Journal of Electron Spectroscopy and Related Phenomena, 2002
AIP Conference Proceedings, 2004
ABSTRACT We describe the construction and testing of a supersonic jet apparatus to carry out elec... more ABSTRACT We describe the construction and testing of a supersonic jet apparatus to carry out electron spectroscopy on Van-der-Waals clusters using Synchrotron Radiation as an excitation source. The cluster source works with a conical nozzle that can be cooled with LHe as well as with LN2. The system has been optimized for mechanical and thermal stability, for low residual magnetic fields and is of a compact design.
ABSTRACT Molecule frame electron angular distribution in the gas phase have attracted increasing ... more ABSTRACT Molecule frame electron angular distribution in the gas phase have attracted increasing interest during the last five years after the first of such distributions was measured [1]. The studies were extended over a variety of molecules and performed for core ionization as well as valence ionization [2, 3]. Experimentally such studies are measurements of vector correlations between the emission directions of electrons and fragment ions produced via the photoionization or -excitation process. The corresponding angular distribu-tions provide a wealth of information on the dynamics of molecular photoionization, in particular dipole transition matrix elements and their corresponding phases. Some of these experiments are expected to be sensitive to the coherence properties of the photoemission process in the case of homonuclear molecules, a problem closely related to the core-hole localization [4-6]. We have performed two types of experi-ments of this subject, one concerned with the ejection of a 1s photoelectron of N 2 in the vicinity of the σ shape resonance and the other exploring the Auger angular distributions after photoexcitation of N 2 to the π* resonance. Both experiments are intended to shed some light on the problem to which extend core holes in N 2 are localized or delocalized. The experiments were performed at beamline BW3 using an angle resolved fragment-ion-electron coincidence setup. This setup consists of a ion time-of-flight spectrometer having position sensitive anode combined with five independent electron time-of-flight spectrometers in order to allow for the angle resolved detection of both particles in coincidence [3].
The Journal of Physical Chemistry A, 2001
Review of Scientific Instruments, 2003
We have determined the transit time distribution of electrons passing a high resolution hemispher... more We have determined the transit time distribution of electrons passing a high resolution hemispherical energy analyzer. Comparison of our measured results with analytical expressions reveals that differing transit times between electrons of equal kinetic energy mainly build up on the Kepler-type orbits on which the electrons travel through the hemispheres. To facilitate the measurements, we have installed a position sensitive electron detector capable of single event detection into our spectrometer. This device is based on a delay-line anode. We briefly report on the energy resolution achieved in comparison with a slower readout system via a fluorescent screen. The transit time distribution is important in coincidence experiments, where electrons detected in the hemispherical analyzer are to be related to events in other detectors. We discuss the feasibility of electron–electron coincidence experiments using a hemispherical detector plus a time-of-flight drift tube for energy discrim...
Journal of Physics: Conference Series, 2012
Journal of Physics: Conference Series, 2009
Journal of Electron Spectroscopy and Related Phenomena, 2002