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Poline M, Dochain A, Rosén S, Grumer J, Ji M, Eklund G, Simonsson A, Reinhed P, Blom M, Shuman NS, Ard SG, Viggiano AA, Larsson M, Cederquist H, Schmidt HT, Zettergren H, Urbain X, Barklem PS, Thomas RD. Mutual neutralisation of O + with O -: investigation of the role of metastable ions in a combined experimental and theoretical study. Phys Chem Chem Phys 2021; 23:24607-24616. [PMID: 34726204 DOI: 10.1039/d1cp03977f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mutual neutralisation of O+ with O- has been studied in a double ion-beam storage ring with combined merged-beams, imaging and timing techniques. Branching ratios were measured at the collision energies of 55, 75 and 170 (± 15) meV, and found to be in good agreement with previous single-pass merged-beams experimental results at 7 meV collision energy. Several previously unidentified spectral features were found to correspond to mutual neutralisation channels of the first metastable state of the cation (O+(2Do), τ ≈ 3.6 hours), while no contributions from the second metastable state (O+(2Po), τ ≈ 5 seconds) were observed. Theoretical calculations were performed using the multi-channel Landau-Zener model combined with the anion centered asymptotic method, and gave good agreement with several experimentally observed channels, but could not describe well observed contributions from the O+(2Do) metastable state as well as channels involving the O(3s 5So) state.
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Affiliation(s)
- Mathias Poline
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Arnaud Dochain
- Institute of condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Stefan Rosén
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Jon Grumer
- Theoretical Astrophysics, Department of Physics and Astronomy, Uppsala University, Box 516, S 75120, Uppsala, Sweden
| | - MingChao Ji
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Gustav Eklund
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Ansgar Simonsson
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Peter Reinhed
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Mikael Blom
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Nicholas S Shuman
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, NM 87117, USA
| | - Shaun G Ard
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, NM 87117, USA
| | - Albert A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, NM 87117, USA
| | - Mats Larsson
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Henrik Cederquist
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Henning T Schmidt
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Henning Zettergren
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
| | - Xavier Urbain
- Institute of condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Paul S Barklem
- Theoretical Astrophysics, Department of Physics and Astronomy, Uppsala University, Box 516, S 75120, Uppsala, Sweden
| | - Richard D Thomas
- Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden.
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2
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Shafir D, Novotny S, Buhr H, Altevogt S, Faure A, Grieser M, Harvey AG, Heber O, Hoffmann J, Kreckel H, Lammich L, Nevo I, Pedersen HB, Rubinstein H, Schneider IF, Schwalm D, Tennyson J, Wolf A, Zajfman D. Rotational cooling of HD+ molecular ions by superelastic collisions with electrons. PHYSICAL REVIEW LETTERS 2009; 102:223202. [PMID: 19658863 DOI: 10.1103/physrevlett.102.223202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Indexed: 05/28/2023]
Abstract
Merging an HD+ beam with velocity matched electrons in a heavy ion storage ring we observed rapid cooling of the rotational excitations of the HD+ ions by superelastic collisions (SEC) with the electrons. The cooling process is well described using theoretical SEC rate coefficients obtained by combining the molecular R-matrix approach with the adiabatic nuclei rotation approximation. We verify the DeltaJ=-2 SEC rate coefficients, which are predicted to be dominant as opposed to the DeltaJ=-1 rates and to amount to (1-2)x10;{-6} cm;{3} s;{-1} for initial angular momentum states with J< or =7, to within 30%.
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Affiliation(s)
- D Shafir
- Department of Particle Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
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3
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Thomas RD. When electrons meet molecular ions and what happens next: dissociative recombination from interstellar molecular clouds to internal combustion engines. MASS SPECTROMETRY REVIEWS 2008; 27:485-530. [PMID: 18618616 DOI: 10.1002/mas.20169] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interaction of matter with its environment is the driving force behind the evolution of 99% of the observed matter in the universe. The majority of the visible universe exists in a state of weak ionization, the so called fourth state of matter: plasma. Plasmas are ubiquitous, from those occurring naturally; interstellar molecular clouds, cometary comae, circumstellar shells, to those which are anthropic in origin; flames, combustion engines and fusion reactors. The evolution of these plasmas is driven by the interaction of the plasma constituents, the ions, and the electrons. One of the most important subsets of these reactions is electron-molecular ion recombination. This process is significant for two very important reasons. It is an ionization reducing reaction, removing two ionised species and producing neutral products. Furthermore, these products may themselves be reactive radical species which can then further drive the evolution of the plasma. The rate at which the electron reacts with the ion depends on many parameters, for examples the collision energy, the internal energy of the ion, and the structure of the ion itself. Measuring these properties together with the manner in which the system breaks up is therefore critical if the evolution of the environment is to be understood at all. Several techniques have been developed to study just such reactions to obtain the necessary information on the parameters. In this paper the focus will be on one the most recently developed of these, the Ion Storage Ring, together with the detection tools and techniques used to extract the necessary information from the reaction.
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Affiliation(s)
- Richard D Thomas
- Department of Physics, Albanova University Centre, Stockholm University, S106 91 Stockholm, Sweden.
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4
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Novotny S, Rubinstein H, Buhr H, Novotný O, Hoffmann J, Mendes MB, Orlov DA, Krantz C, Berg MH, Froese M, Jaroshevich AS, Jordon-Thaden B, Lange M, Lestinsky M, Petrignani A, Shafir D, Zajfman D, Schwalm D, Wolf A. Anisotropy and molecular rotation in resonant low-energy dissociative recombination. PHYSICAL REVIEW LETTERS 2008; 100:193201. [PMID: 18518450 DOI: 10.1103/physrevlett.100.193201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Indexed: 05/26/2023]
Abstract
Angular fragment distributions from the dissociative recombination (DR) of HD(+) were measured with well directed monochromatic low-energy electrons over a dense grid of collision energies from 7 to 35 meV, where pronounced rovibrational Feshbach resonances occur. Significant higher-order anisotropies are found in the distributions, whose size varies along energy in a partial correlation with the relative DR rate from fast-rotating molecules. This may indicate a breakdown of the nonrotation assumption so far applied to predict angular DR fragment distributions.
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Affiliation(s)
- S Novotny
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
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5
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Laser photoelectron spectroscopy: spectroscopy and dynamics of excited states in small and medium-sized molecules. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141779.ch1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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6
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Adams NG, Poterya V, Babcock LM. Electron molecular ion recombination: product excitation and fragmentation. MASS SPECTROMETRY REVIEWS 2006; 25:798-828. [PMID: 16783766 DOI: 10.1002/mas.20084] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Electron-ion dissociative recombination is an important ionization loss process in any ionized gas containing molecular ions. This includes the interstellar medium, circumstellar shells, cometary comae, planetary ionospheres, fusion plasma boundaries, combustion flames, laser plasmas and chemical deposition and etching plasmas. In addition to controlling the ionization density, the process generates many radical species, which can contribute to a parallel neutral chemistry. Techniques used to obtain rate data and product information (flowing afterglows and storage rings) are discussed and recent data are reviewed including diatomic to polyatomic ions and cluster ions. The data are divided into rate coefficients and cross sections, including their temperature/energy dependencies, and quantitative identification of neutral reaction products. The latter involve both ground and electronically excited states and including vibrational excitation. The data from the different techniques are compared and trends in the data are examined. The reactions are considered in terms of the basic mechanisms (direct and indirect processes including tunneling) and recent theoretical developments are discussed. Finally, new techniques are mentioned (for product identification; electrostatic storage rings, including single and double rings; Coulomb explosion) and new ways forward are suggested.
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Affiliation(s)
- Nigel G Adams
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.
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7
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Strasser D, Lammich L, Krohn S, Lange M, Kreckel H, Levin J, Schwalm D, Vager Z, Wester R, Wolf A, Zajfman D. Two- and three-body kinematical correlation in the dissociative recombination of H(3)(+). PHYSICAL REVIEW LETTERS 2001; 86:779-782. [PMID: 11177938 DOI: 10.1103/physrevlett.86.779] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2000] [Indexed: 05/23/2023]
Abstract
Fragmentation patterns for dissociative recombination of the triatomic hydrogen molecular ion H(3)(+) in the vibrational ground state have been measured using the storage ring technique and molecular fragment imaging. A broad distribution of vibrational states in the H(2) fragment after two-body dissociation and a large predominance of nearly linear momentum geometries after three-body dissociation are found. The fragmentation results are directly contrasted with Coulomb explosion imaging data on the initial H(3)(+) geometry, compared to existing wave-packet calculations, and considered in the light of a simple physical picture.
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Affiliation(s)
- D Strasser
- Department of Particle Physics, Weizmann Institute of Science, Rehovet, Israel
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8
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Merged-beams studies of electron-molecular ion interactions in ion storage rings. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1071-9687(01)80008-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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9
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Dissociation of H2 in the energy region at the H(n=1)+H(n=3) dissociation threshold after (1+1′) resonance-enhanced two-photon ionization via the B1Σ+u state. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00967-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Affiliation(s)
| | - Jack Simons
- Chemistry Department, University of Utah, Salt Lake City, Utah 84112
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11
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Le Padellec A, Mitchell JBA, Al-Khalili A, Danared H, Källberg A, Larson Å, Rosén S, af Ugglas M, Vikor L, Larsson M. Storage ring measurements of the dissociative recombination and excitation of the cyanogen ion CN+(X 1Σ+ and a 3Π, ν=0). J Chem Phys 1999. [DOI: 10.1063/1.478056] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Scheper CR, Buma WJ, de Lange CA, van der Zande WJ. Photoionization and photodissociation dynamics of H2 after (3+1) resonance-enhanced multiphoton ionization via the B 1Σu+ state. J Chem Phys 1998. [DOI: 10.1063/1.477495] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Peterson JR, Le Padellec A, Danared H, Dunn GH, Larsson M, Larson A, Peverall R, Strömholm C, Rosén S, af Ugglas M, van der Zande WJ. Dissociative recombination and excitation of N2+: Cross sections and product branching ratios. J Chem Phys 1998. [DOI: 10.1063/1.475577] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Abstract
The development of heavy-ion storage-cooler rings for atomic physics has made it possible to produce high-quality beams of molecular ions that are internally cold. The stored molecular-ion beam is immersed in a cold electron bath, which gives a beam of low divergence and small cross-sectional area. The electron cooler also serves as a target for electron-molecular ion collision experiments. This allows the study of dissociative recombination of cold molecules with respect to cross sections, branching ratios, and angular distributions at an unprecedented luminosity.
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Affiliation(s)
- M Larsson
- Department of Physics, Stockholm University, PO Box 6730, Stockholm, S-113 85 Sweden.
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15
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Kella D, Vejby-Christensen L, Johnson PJ, Pedersen HB, Andersen LH. The Source of Green Light Emission Determined from a Heavy-Ion Storage Ring Experiment. Science 1997. [DOI: 10.1126/science.276.5318.1530] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- D. Kella
- Institute of Physics and Astronomy, University of Aarhus, DK 8000, Aarhus C, Denmark
| | - L. Vejby-Christensen
- Institute of Physics and Astronomy, University of Aarhus, DK 8000, Aarhus C, Denmark
| | - P. J. Johnson
- Institute of Physics and Astronomy, University of Aarhus, DK 8000, Aarhus C, Denmark
| | - H. B. Pedersen
- Institute of Physics and Astronomy, University of Aarhus, DK 8000, Aarhus C, Denmark
| | - L. H. Andersen
- Institute of Physics and Astronomy, University of Aarhus, DK 8000, Aarhus C, Denmark
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16
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Semaniak J, Zengin V, Sundström G, Rosén S, Strömholm C, Datz S, Danared H, Larsson M. Dissociative recombination of H2 +: Product state information and very large cross sections of vibrationally excited H2 +. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:5010-5018. [PMID: 9914068 DOI: 10.1103/physreva.54.5010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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17
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Semaniak J, Rosén S, Sundström G, Strömholm C, Datz S, Danared H, Larsson M, Amitay Z, Hechtfischer U, Grieser M, Repnow R, Schmidt M, Schwalm D, Wester R, Wolf A, Zajfman D. Product-state distributions in the dissociative recombination of 3HeD+ and 4HeH+. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:R4617-R4620. [PMID: 9914131 DOI: 10.1103/physreva.54.r4617] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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18
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Amitay Z, Zajfman D, Forck P, Hechtfischer U, Seidel B, Grieser M, Habs D, Repnow R, Schwalm D, Wolf A. Dissociative recombination of CH+: Cross section and final states. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:4032-4050. [PMID: 9913951 DOI: 10.1103/physreva.54.4032] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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19
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Strömholm C, Semaniak J, Rosén S, Danared H, Datz S, Larsson M. Dissociative recombination and dissociative excitation of 4HeH+: Absolute cross sections and mechanisms. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:3086-3094. [PMID: 9913828 DOI: 10.1103/physreva.54.3086] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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20
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Kella D, Johnson PJ, Pedersen HB, Vejby-Christensen L, Andersen LH. Branching Ratios for Dissociative Recombination of 15N14 N+. PHYSICAL REVIEW LETTERS 1996; 77:2432-2435. [PMID: 10061952 DOI: 10.1103/physrevlett.77.2432] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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