Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Single-photon multiple ionization processes studied by electron coincidence spectroscopy
Stockholm University, Faculty of Science, Department of Physics.
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis is based on studies of multiple ionization of atoms and molecules induced by the absorption of a single photon. For the experimental investigations a time-of-flight magnetic bottle spectrometer has been used to detect the emitted electrons in coincidence. The method of coincidence time-of-flight spectroscopy and the experimental setup used is described. Experimental and theoretical results on molecular double core holes (DCHs) and multiple ionization of atoms are presented.

Molecular DCHs are of considerable interest, as their chemical shifts are predicted to be more sensitive than their single core hole counterparts. Using CH4 and NH3 as examples, it is shown that molecules with two vacancies in the innermost shell can be studied using synchrotron light in combination with our coincidence technique. The chemical shifts of S 2p DCHs are investigated for the molecules CS2, H2S and SO2 and the influence of relaxation effects on the shifts are estimated. In the studies of atoms, the main focus is on the processes leading to double and higher degrees of ionization, and the final state populations. In cadmium double photoionization in the photon energy region 40-200 eV occurs mainly by indirect ionization via valence ionized satellite states and through Coster-Kronig decay of inner shell hole states. In valence-valence ionization of krypton by 88 eV photons both direct and indirect ionization processes are found to be important. For the indirect pathways strong final state selectivity in the autoionization decays of the intermediate states is observed. Triple ionization of krypton via intermediate core-valence doubly ionized states is investigated. The intermediate states are observed in the energy region 120-125 eV, and their decay to states of the triply charged ion is mapped. Experimental and theoretical results on the formation of 2p double hole states in argon are presented.

Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University , 2013. , 61 p.
Keyword [en]
photoionization, multiple ionization, autoionization, synchrotron radiation, electron coincidence spectroscopy
National Category
Physical Sciences
Research subject
Physics
Identifiers
URN: urn:nbn:se:su:diva-89601ISBN: 978-91-7447-710-8 (print)OAI: oai:DiVA.org:su-89601DiVA: diva2:619056
Public defence
2013-06-07, Lecture Hall FB42, AlbaNova University Center, Roslagstullsbacken 21, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.

Available from: 2013-05-16 Created: 2013-05-01 Last updated: 2013-05-13Bibliographically approved
List of papers
1. Double Core Hole Creation and Subsequent Auger Decay in NH3 and CH4 Molecules
Open this publication in new window or tab >>Double Core Hole Creation and Subsequent Auger Decay in NH3 and CH4 Molecules
Show others...
2010 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 105, no 21, 213005- p.Article in journal (Refereed) Published
Abstract [en]

Energies of the hollow molecules CH42+ and NH32+ with double vacancies in the 1s shells have been measured using an efficient coincidence technique combined with synchrotron radiation. The energies of these states have been determined accurately by high level electronic structure calculations and can be well understood on the basis of a simple theoretical model. Their major decay pathway, successive Auger emissions, leads first to a new form of triply charged ion with a core hole and two valence vacancies; experimental evidence for such a state is presented with its theoretical interpretation. Preedge 2-hole-1-particle (2h-1p) states at energies below the double core-hole states are located in the same experiments and their decay pathways are also identified.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-51333 (URN)10.1103/PhysRevLett.105.213005 (DOI)000284407400011 ()
Note

authorCount :6

Available from: 2011-01-11 Created: 2011-01-10 Last updated: 2017-12-11Bibliographically approved
2. Structure sensitivity of double inner-shell holes in sulfur-containing molecules
Open this publication in new window or tab >>Structure sensitivity of double inner-shell holes in sulfur-containing molecules
Show others...
2011 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 83, no 2, 022506- p.Article in journal (Refereed) Published
Abstract [en]

To demonstrate the structure sensitivity of double inner-shell hole spectroscopy, we have measured energies of H(2)S(2+), SO(2)(2+), and CS(2)(2+) with the two vacancies in the sulfur 2p shell using a multielectron coincidence technique combined with synchrotron radiation. We describe how to extract intrinsic chemical information which is masked by the orbital relaxation effect in conventional core-level photoelectron spectroscopy.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-67498 (URN)10.1103/PhysRevA.83.022506 (DOI)000287482500008 ()
Note

authorCount :5

Available from: 2011-12-29 Created: 2011-12-28 Last updated: 2017-12-08Bibliographically approved
3. Double ionization of atomic cadmium
Open this publication in new window or tab >>Double ionization of atomic cadmium
Show others...
2011 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 83, no 2, 023424- p.Article in journal (Refereed) Published
Abstract [en]

We have recorded the double photoionization spectrum of atomic Cd at four different photon energies in the range 40-200 eV. The main channel is single ionization and subsequent decay of excited Cd(+) states, some involving Coster-Kronig processes, whereas direct double ionization is found to be weak. The decay of the excited Cd(+) states shows a strong selectivity, related to the configuration of the final state. Double ionization leading to the Cd(2+) ground state is investigated in some detail and is found to proceed mainly through ionization and decay of 4d correlation satellites. The most prominent autoionization peaks have been identified with the aid of quantum-mechanical calculations.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-67932 (URN)10.1103/PhysRevA.83.023424 (DOI)000287795200013 ()
Note

authorCount :6

Available from: 2012-01-02 Created: 2012-01-02 Last updated: 2017-12-08Bibliographically approved
4. A complete double valence photoionization study of the electron spectra of krypton
Open this publication in new window or tab >>A complete double valence photoionization study of the electron spectra of krypton
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-89597 (URN)
Funder
Knut and Alice Wallenberg FoundationSwedish Research Council
Available from: 2013-05-01 Created: 2013-05-01 Last updated: 2013-05-02Bibliographically approved
5. Formation of Kr3+ via core-valence doubly ionized intermediate states
Open this publication in new window or tab >>Formation of Kr3+ via core-valence doubly ionized intermediate states
Show others...
2012 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 85, no 3, 032502- p.Article in journal (Refereed) Published
Abstract [en]

The time-of-flight photoelectron-photoion coincidence technique has been used to study single-photon 3d(9)4p(5) core-valence double ionization of Kr and subsequent Auger decay to triply charged states associated with the 4s(2)4p(3) and 4s(1)4p(4) configurations. The photon energy used was h nu = 150 eV. Multiconfiguration Dirac-Fock calculations were performed both for the doubly ionized intermediate states and the triply ionized final states. The intermediate states of Kr2+ are observed between 120 and 125 eV, whereas the final states of Kr3+ are observed between 74- and 120-eV ionization energy. Assignments of all structures are made based on the present numerical results. The calculated Auger rates give a detailed explanation of the relative line strengths observed.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-76284 (URN)10.1103/PhysRevA.85.032502 (DOI)000301104400014 ()
Note

8

Available from: 2012-05-15 Created: 2012-05-10 Last updated: 2017-12-07Bibliographically approved
6. Single-photon multiple ionization forming double vacancies in the 2p subshell of argon
Open this publication in new window or tab >>Single-photon multiple ionization forming double vacancies in the 2p subshell of argon
Show others...
2013 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 87, no 4, 043409- p.Article in journal (Refereed) Published
Abstract [en]

Single-photon ionization leading to two vacancies in the 2p subshell of argon is investigated experimentally using the photoelectron time-of-flight magnetic bottle coincidence technique. Three peaks corresponding to the 3P, 1D, and 1S states of the dication are found in the ionization energy range 535 to 562 eV. Multiconfigurational Dirac-Fock calculations were performed to estimate the single-photon double-ionization cross sections. Reasonable agreement between the measured and simulated spectra is found if single and double excitations are taken into account in the wave-function expansion.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-89599 (URN)10.1103/PhysRevA.87.043409 (DOI)000317388700007 ()
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Available from: 2013-05-01 Created: 2013-05-01 Last updated: 2017-12-06Bibliographically approved
7. Versatile high-repetition-rate phase-locked chopper system for fast timing experiments in the vacuum ultraviolet and x-ray spectral region
Open this publication in new window or tab >>Versatile high-repetition-rate phase-locked chopper system for fast timing experiments in the vacuum ultraviolet and x-ray spectral region
Show others...
2012 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 83, no 1, 013115- p.Article in journal (Refereed) Published
Abstract [en]

A novel light chopper system for fast timing experiments in the vacuum-ultraviolet (VUV) and x-ray spectral region has been developed. It can be phase-locked and synchronized with a synchrotron radiation storage ring, accommodating repetition rates in the range of similar to 8 to similar to 120 kHz by choosing different sets of apertures and subharmonics of the ring frequency (MHz range). Also the opening time of the system can be varied from some nanoseconds to several microseconds to meet the needs of a broad range of applications. Adjusting these parameters, the device can be used either for the generation of single light pulses or pulse packages from a microwave driven, continuous He gas discharge lamp or from storage rings which are otherwise often considered as quasi-continuous light sources. This chopper can be utilized for many different kinds of experiments enabling, for example, unambiguous time-of-flight (TOF) multi-electron coincidence studies of atoms and molecules excited by a single light pulse as well as time-resolved visible laser pump x-ray probe electron spectroscopy of condensed matter in the valence and core level region.

National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-76763 (URN)10.1063/1.3677329 (DOI)000300594900016 ()
Note

8

Available from: 2012-05-16 Created: 2012-05-16 Last updated: 2017-12-07Bibliographically approved

Open Access in DiVA

fulltext(1647 kB)765 downloads
File information
File name FULLTEXT01.pdfFile size 1647 kBChecksum SHA-512
3be34c427484fefc87afe22615df9fa5ce92f8ecc2b09000dae3a1fd07692ec1079563562bd0b5a107dbc9ec4b64da060a78e1dc74d542894b24e173c405360e
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Linusson, Per
By organisation
Department of Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 765 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 283 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf