| 61. |
- Vigren, Erik, et al.
(författare)
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Dissociative recombination of the deuterated acetaldehyde ion, CD3CDO+ : product branching fractions, absolute cross sections and thermal rate coefficient
- 2007
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - 1463-9076 .- 1463-9084. ; 9:22, s. 2856-2861
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Tidskriftsartikel (refereegranskat)abstract
- Dissociative recombination of the deuterated acetaldehyde ion CD3CDO+ has been studied at the heavy-ion storage ring CRYRING, located at the Manne Siegbahn Laboratory, Stockholm, Sweden. Product branching fractions together with absolute DR cross-sections were measured. The branching fractions were determined at a relative collision energy between the ions and the electrons of 0 eV. With a probability of 34% the DR events resulted in no ruptures of bonds between heavy atoms (i.e. no breakage of the C–C bond or the CO bond). In the remaining 66% of the events one of the bonds between the heavy atoms was broken. The energy-dependent cross-section for the DR reaction was measured between 0 and 1 eV relative kinetic energy. In the energy region between 1 meV and 0.2 eV the absolute cross section could be fitted by the expression σ(E) = 6.8 × 10−16E−1.28 cm2, whereas in the energy interval between 0.2 and 1 eV the data were best fitted by σ(E) = 4.1 × 10−16E−1.60 cm2. From these cross section data the thermal rate coefficient (as a function of the electron temperature), α(T) = 9.2 × 10−7 (T/300)−0.72 cm3 s−1 was obtained.
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| 62. |
- Vigren, Erik, et al.
(författare)
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The Dissociative Recombination of Protonated Acrylonitrile, CH2CHCNH+, with implications for the Nitrile Chemistry in Dark Molecular Clouds and the Upper Atmosphere of Titan
- 2009
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 695:1, s. 317-324
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Tidskriftsartikel (refereegranskat)abstract
- Measurements on the dissociative recombination (DR) of protonated acrylonitrile, CH2CHCNH+, have been performed at the heavy ion storage ring CRYRING located in the Manne Siegbahn Laboratory in Stockholm, Sweden. It has been found that at similar to 2meV relative kinetic energy about 50% of the DR events involve only ruptures of X-Hbonds (where X = C or N) while the rest leads to the production of a pair of fragments each containing two heavy atoms (alongside H and/or H-2). The absolute DR cross section has been investigated for relative kinetic energies ranging from similar to 1 meV to 1 eV. The thermal rate coefficient has been determined to follow the expression k(T) = 1.78 x 10(-6) (T/300)(-0.80) cm(3) s(-1) for electron temperatures ranging from similar to 10 to 1000 K. Gas-phase models of the nitrile chemistry in the dark molecular cloud TMC-1 have been run and results are compared with observations. Also, implications of the present results for the nitrile chemistry of Titan's upper atmosphere are discussed.
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| 63. |
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| 64. |
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| 65. |
- Zhaunerchyk, Vitali, et al.
(författare)
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Dissociative recombination of D2H+ : Comparison between recent storage-ring results and theoretical calculations
- 2008
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 77:3, s. 34701-
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Tidskriftsartikel (refereegranskat)abstract
- The most up-to-date theoretical calculation on the dissociative recombination (DR) of D2H+ predicts a 2-5 times lower rate coefficient than that obtained experimentally at the Test Storage Ring (TSR). In order to verify the validity either of the experimental results or the theoretical calculations we have studied the DR of D2H+ at the storage ring CRYRING. The rate coefficient has been measured over the interaction energy range from approximate to 0 eV to 50 eV and has been found to have a peak at about 10 eV with a value of 1.6 x 10(-8) cm(3) s(-1), which is in excellent agreement with the result reported from TSR. Taking into account the electron temperature distributions, excellent agreement between the two storage rings measurements is also obtained at smaller interaction energies. The branching fraction analysis has been performed at approximate to 0 eV interaction energy and revealed the following results at the 1 sigma confidence level: N(D+D+H)=76.5%+/-2.2%, N(D-2+H)= 10.0%+/-0.7%, and N(DH+D)=13.5%+/-1.5%. The value of 2N(D-2+H)/N(DH+D)=1.48+/-0.22 implies that formation of D-2 is more favorable than DH.
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| 66. |
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| 67. |
- Zhaunerchyk, V., et al.
(författare)
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Dissociative recombination study of N-3(+) : Cross section and branching fraction measurements
- 2007
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 127:1, s. 014305-
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Tidskriftsartikel (refereegranskat)abstract
- We report an investigation into the dissociative recombination of the azide radical cation, N-3(+). The reaction rate constant has been measured to be 6.47x10(-7) cm(3) s(-1) at room temperature. This value is smaller than those reported earlier for the ion-electron neutralization of N-3(+) at nitrogen atmospheric pressure. A strong propensity to dissociate through the N-2+N channel has been observed.
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| 68. |
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| 69. |
- Zhaunerchyk, Vitali, et al.
(författare)
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Investigation into the vibrational yield of OH products in the OH plus H plus H channel arising from the dissociative recombination of H3O
- 2009
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 130:21, s. 214302-
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Tidskriftsartikel (refereegranskat)abstract
- The vibrational population of the hydroxyl radical, OH, formed in the OH+H+H channel arising from the dissociative recombination of the hydronium ion, H3O+, has been investigated at the storage ring CRYRING using a position-sensitive imaging detector. Analysis shows that the OH fragments are predominantly produced in the v=0 and v=1 states with almost equal probabilities. This observation is in disagreement with earlier FALP experiments, which reported OH(v=0) as the dominant product. Possible explanations for this difference are discussed.
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| 70. |
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