Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Ioniztion of molecules at the CRYRING facility
KTH, School of Engineering Sciences (SCI), Physics.
2006 (English)Licentiate thesis, comprehensive summary (Other scientific)
Place, publisher, year, edition, pages
Stockholm: KTH , 2006. , 40 p.
Series
Trita-FYS, ISSN 0280-316X ; 2006.42
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-3993OAI: oai:DiVA.org:kth-3993DiVA: diva2:10296
Presentation
2006-06-08, Sal FA32, AlbaNova, Roslagstullsbacken 21, Stockholm, 09:00
Opponent
Supervisors
Note
QC 20101124Available from: 2006-05-24 Created: 2006-05-24 Last updated: 2010-11-24Bibliographically approved
List of papers
1. Dissociative recombination of D+(D2O)(2) water cluster ions with free electrons
Open this publication in new window or tab >>Dissociative recombination of D+(D2O)(2) water cluster ions with free electrons
Show others...
2002 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 117, no 11, 5264-5270 p.Article in journal (Refereed) Published
Abstract [en]

Dissociative recombination (DR) of the water cluster ion D+(D2O)(2) has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). Cluster ions were injected into the ring and accelerated to an energy of 2.28 MeV. The stored ion beam was merged with an almost monoenergetic electron beam, and neutral fragments produced by DR were detected by an energy-sensitive surface barrier detector. The first experimental determinations of the absolute DR cross section and branching ratios for a cluster ion are reported. The cross section for the process D+(D2O)(2)+e(-) is large and reaches 6.10(-12) cm(2) at a low center-of-mass collision energy of 0.001 eV. The cross section has an E-1.19+/-0.02 dependence in the energy range 0.001-0.0052 eV, and a steeper slope with an E-1.70+/-0.12 dependence for E=0.052-0.324 eV. The general trends are similar to the results for previously studied molecular ions, but the cross section is higher in absolute numbers for the cluster ion. Thermal rate coefficients for electron temperatures of 50-2000 K are deduced from the cross section data and the rate coefficients are consequently also large. Branching ratios for the product channels are determined with a grid technique. Break-up into 2D(2)O+D is the dominating dissociation channel with a probability of 0.94+/-0.04. The channel resulting in the fragments D2O+OD+D-2 has a probability of 0.04+/-0.02, and the probability for formation of D3O+D2O is 0.02+/-0.03. The results are compared with data for molecular ions, and the cluster dissociation dynamics are discussed.

Keyword
Deuterium, Dissociation, Electron beams, Electron transitions, Heavy ions, Particle detectors, Plasma sources, Scintillation, Storage rings
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-26365 (URN)10.1063/1.1486436 (DOI)000177684400018 ()
Note
QC 20101124Available from: 2010-11-24 Created: 2010-11-24 Last updated: 2017-12-12Bibliographically approved
2. Dissociative recombination of NH4+ and ND4+ ions: Storage ring experiments and ab initio molecular dynamics
Open this publication in new window or tab >>Dissociative recombination of NH4+ and ND4+ ions: Storage ring experiments and ab initio molecular dynamics
Show others...
2004 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 120, no 16, 7391-7399 p.Article in journal (Refereed) Published
Abstract [en]

The dissociative recombination (DR) process of NH4+ and ND4+ molecular ions with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). The absolute cross sections for DR of NH4+ and ND4+ in the collision energy range 0.001-1 eV are reported, and thermal rate coefficients for the temperature interval from 10 to 2000 K are calculated from the experimental data. The absolute cross section for NH4+ agrees well with earlier work and is about a factor of 2 larger than the cross section for ND4+. The dissociative recombination of NH4+ is dominated by the product channels NH3+H (0.85+/-0.04) and NH2+2H (0.13+/-0.01), while the DR of ND4+ mainly results in ND3+D (0.94+/-0.03). Ab initio direct dynamics simulations, based on the assumption that the dissociation dynamics is governed by the neutral ground-state potential energy surface, suggest that the primary product formed in the DR process is NH3+H. The ejection of the H atom is direct and leaves the NH3 molecule highly vibrationally excited. A fraction of the excited ammonia molecules may subsequently undergo secondary fragmentation forming NH2+H. It is concluded that the model results are consistent with gross features of the experimental results, including the sensitivity of the branching ratio for the three-body channel NH2+2H to isotopic exchange.

Keyword
Ammonia, Computer simulation, Dissociation, Energy transfer, Ion exchange, Ionization, Isotopes, Mathematical models, Molecular vibrations, Positive ions, Potential energy, Probability, Storage rings, Thermal effects
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-26366 (URN)10.1063/1.1669388 (DOI)000220676000018 ()2-s2.0-2342470002 (Scopus ID)
Note
QC 20101124Available from: 2010-11-24 Created: 2010-11-24 Last updated: 2017-12-12Bibliographically approved
3. Rate constants and branching ratios for the dissociative recombination of CO2+
Open this publication in new window or tab >>Rate constants and branching ratios for the dissociative recombination of CO2+
Show others...
2005 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 122, no 22, 226101- p.Article in journal (Refereed) Published
Abstract [en]

The calculation of rate constants and branching ratios was carried out to study the dissociative recombination of CO2+. The recombination of CO2+ is significant in the atmospheres of Venus and Mars. Rate constants and cross sections were studied by ramping the electron beam around a center-of-mass energy of 0 eV. The results of the study confirms that all the recombination of CO2+ results in a simple bondbreaking to form CO plus O. The rate constants show good agreement with measurements at 300 K and the electron energy dependence is identical to storage ring results.

Keyword
Chemical bonds, Dissociation, Electron beams, Energy absorption, Extraterrestrial atmospheres, Planets, Rate constants
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-26368 (URN)10.1063/1.1926283 (DOI)000229858500074 ()2-s2.0-20544455025 (Scopus ID)
Note
QC 20101124Available from: 2010-11-24 Created: 2010-11-24 Last updated: 2017-12-12Bibliographically approved
4. The dissociative recombination of fluorocarbon ions III: CF2+ and CF3+
Open this publication in new window or tab >>The dissociative recombination of fluorocarbon ions III: CF2+ and CF3+
Show others...
2006 (English)In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 39, no 4, 805-812 p.Article in journal (Refereed) Published
Abstract [en]

Cross sections and branching ratios are presented for the dissociative recombination of the CF2+ and C-3(+) ions with electrons. It is found that the channel producing CF + F is dominant for the reaction with CF2+ and the production of CF2 + F is dominant for the reaction with CF3+. The cross sections for these two ions are very similar.

Keyword
Dissociation, Electrons, Reaction kinetics
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-26370 (URN)10.1088/0953-4075/39/4/006 (DOI)000237214800010 ()2-s2.0-33645672455 (Scopus ID)
Note
QC 20101124Available from: 2010-11-24 Created: 2010-11-24 Last updated: 2017-12-12Bibliographically approved

Open Access in DiVA

fulltext(1411 kB)575 downloads
File information
File name FULLTEXT01.pdfFile size 1411 kBChecksum MD5
2f454048b9a8b44d025ea4078709ea9fcdcbc6a7cc7550ad5fbf16f605b9659436a80418
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Österdahl, Fabian
By organisation
Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 575 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

urn-nbn

Altmetric score

urn-nbn
Total: 290 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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