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Gas phase molecular relaxation probed by synchrotron radiation experiments

Rius i Riu, Jaume LU (2002)
Abstract
This thesis presents experimental studies of gas phase molecular relaxation after excitation

with synchrotron photons in the 15-35 eV and in the 70-350 eV regions.

In the 15-35 eV region, molecular relaxation by neutral dissociation processes and non

Franck-Condon effects in N2 and O2 molecules have been studied by means of dispersed fluorescence

and photoelectron spectroscopy experimental techniques, respectively. From the dispersed

fluorescence data, excitation functions for the measured atomic fluorescence spectra have been

obtained. From the recorded photoelectron spectra vibrational branching ratios have been produced.

The results obtained reveal that Rydberg series... (More)
This thesis presents experimental studies of gas phase molecular relaxation after excitation

with synchrotron photons in the 15-35 eV and in the 70-350 eV regions.

In the 15-35 eV region, molecular relaxation by neutral dissociation processes and non

Franck-Condon effects in N2 and O2 molecules have been studied by means of dispersed fluorescence

and photoelectron spectroscopy experimental techniques, respectively. From the dispersed

fluorescence data, excitation functions for the measured atomic fluorescence spectra have been

obtained. From the recorded photoelectron spectra vibrational branching ratios have been produced.

The results obtained reveal that Rydberg series and singly and doubly excited valence states of the

appropriate symmetry energetically accessible in the studied region and interactions between them

account for most of the observed effects in these two type of experiments.

In the 70-350 eV range, molecular relaxation processes resulting in fragmentation of CD4 and

SF6 after absorption of synchrotron light have been studied by energy resolved electron ion

coincidence technique using a multicoincidence experimental station developed by our group during

the last five years for such type of experiments. The coincidence measurements yielded mass spectra

from which information about the kinematics of the detected fragments has been deduced by means of

Monte Carlo simulations of the experimental peak shapes. The obtained results show completely

different dissociation patterns depending on the molecular electronic states studied. These patterns

reflect the bonding properties of the excited orbitals and they permit the description and in some cases

the identification of the different molecular relaxation pathways observed. The achievements

presented in this thesis exemplify the potential of the multicoincidence station used in the reported

experiments. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Professor King, George, Manchester University
publishing date
type
Thesis
publication status
published
subject
pages
62 pages
defense location
Stockholm
defense date
2002-10-11 10:00
external identifiers
  • other:ISRN KTH/FYS/-02:32-SE
  • other:TRITA-FYS-2002:32
ISSN
0280-316X
language
English
LU publication?
no
id
bf256c20-8254-4c01-a7c9-36881e1d7e3b (old id 1029529)
date added to LUP
2010-10-18 15:49:43
date last changed
2016-09-19 08:45:00
@phdthesis{bf256c20-8254-4c01-a7c9-36881e1d7e3b,
  abstract     = {This thesis presents experimental studies of gas phase molecular relaxation after excitation <br/><br>
with synchrotron photons in the 15-35 eV and in the 70-350 eV regions. <br/><br>
In the 15-35 eV region, molecular relaxation by neutral dissociation processes and non <br/><br>
Franck-Condon effects in N2 and O2 molecules have been studied by means of dispersed fluorescence <br/><br>
and photoelectron spectroscopy experimental techniques, respectively. From the dispersed <br/><br>
fluorescence data, excitation functions for the measured atomic fluorescence spectra have been <br/><br>
obtained. From the recorded photoelectron spectra vibrational branching ratios have been produced. <br/><br>
The results obtained reveal that Rydberg series and singly and doubly excited valence states of the <br/><br>
appropriate symmetry energetically accessible in the studied region and interactions between them <br/><br>
account for most of the observed effects in these two type of experiments. <br/><br>
In the 70-350 eV range, molecular relaxation processes resulting in fragmentation of CD4 and <br/><br>
SF6 after absorption of synchrotron light have been studied by energy resolved electron ion <br/><br>
coincidence technique using a multicoincidence experimental station developed by our group during <br/><br>
the last five years for such type of experiments. The coincidence measurements yielded mass spectra <br/><br>
from which information about the kinematics of the detected fragments has been deduced by means of <br/><br>
Monte Carlo simulations of the experimental peak shapes. The obtained results show completely <br/><br>
different dissociation patterns depending on the molecular electronic states studied. These patterns <br/><br>
reflect the bonding properties of the excited orbitals and they permit the description and in some cases <br/><br>
the identification of the different molecular relaxation pathways observed. The achievements <br/><br>
presented in this thesis exemplify the potential of the multicoincidence station used in the reported <br/><br>
experiments.},
  author       = {Rius i Riu, Jaume},
  issn         = {0280-316X},
  language     = {eng},
  pages        = {62},
  title        = {Gas phase molecular relaxation probed by synchrotron radiation experiments},
  year         = {2002},
}