Angular dependence of vibronic excitation in He<sup>+</sup>+CO, N<sub>2</sub>collisions at medium energies: evidence for non-Franck-Condon and non-Poisson vibrational distributions

Dhuicq, D; Sidis, V.

doi:10.1088/0022-3700/20/19/019

Cited by 12 publications

(4 citation statements)

References 31 publications

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“…Cross sections have been measured for Balmer alpha emission in collisions of 10–100 keV 11 2 molecules with N 2 , O 2 , H 2 0, and CH 4 by Geddes et al [1990]. Dhuicq and Sidis [1987] have measured the vibrational distribution of CO( υ ) and N 2 ( υ ) produced by low energy (100–1000 eV) impact of He + on CO and N 2 ; Dhuicq [1990] has performed model calculations of vibrational excitation for the same systems. Monte* [1990] has measured 5876‐A photon emission cross sections for collisions of 100–300 keV protons with a number of molecules, including H 2 , N 2 , O 2 , CO, CO 2 , N 2 O, CH 4 , C 2 H 2 , C 2 H 46 , and C 2 H 6 .…”

Section: Heavy Particle Impactmentioning

confidence: 99%

Cross Sections and Reaction Rates of Relevance to Aeronomy

Fox

1991

Reviews of Geophysics

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Experimental and theoretical data relevant to models and measurements of the chemical and thermal structures and luminosity of the thermospheres of the Earth and planets published during the last four years are surveyed, and those in which one or more authors is affiliated with a U.S. institution are indicated. Among chemical processes, we include ion‐molecule reactions, dissociative recombination of molecular ions, and reactions between neutral species. Both reactions between ground state species and species in excited states are considered, including energy transfer and quenching. Measured and calculated cross sections for interactions of solar radiation with atmospheric species, such as photoabsorption, photoionization, and photodissociation and related processes are surveyed. Measurements and calculations of cross sections for elastic and inelastic scattering of particles, including electrons, protons, alpha particles, heavier ions, and neutral atoms are also surveyed.

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Section: Heavy Particle Impactmentioning

confidence: 99%

Cross Sections and Reaction Rates of Relevance to Aeronomy

Fox

1991

Reviews of Geophysics

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“…That is true over the entire range of impact energies, from slow ͑eV͒ to very fast ͑MeV͒ collision regimes. Restricting the discussion to nonreactive scattering, experimental studies of dissociative electron transfer, vibronic excitation, correlation, isomer effects, and post-collisional interaction effects are some of the most representative examples; see, e.g., [1][2][3][4][5][6][7][8][9][10][11][12] and references therein. For diatomic molecules electronic emission spectra have recently shown interference phenomena resulting in oscillatory relative double-differential cross sections [13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Classical and semiclassical calculations of electron transfer cross sections inkeV-energy ion-molecule collisions

et al. 2004

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We apply a many-body classical model and a semiclassical coupled-channel approach to study the electronic processes occurring in the course of fast collisions between atomic and molecular species. The methods are applied in a comparative study of electron transfer in He 2+ /Ar 2+ −H 2 + collisions at keV u −1 impact energies.The classical calculations are in agreement with recent experimental data [H. Bräuning et al., J. Phys. B 34, L321 (2001)] for projectile velocities larger than the initial electron velocity. The semiclassical model is based on the sudden approximation where the electronic wave function is expressed by linear combinations of traveling atomic capture states and target molecular states obtained at fixed nuclei. The related charge transfer cross sections are slightly underestimated (overestimated) for He 2+ ͑Ar 2+ ͒ when considering H 2 + in its initial vibrational ground state. These cross sections do, however, depend strongly on the internuclear distance of the hydrogen molecular ion: when involving an initial vibrational excitation of the target, the averaged cross sections obtained from the semiclassical approach become in fair agreement with experiments.

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“…This work has been preceded by recent studies on H+, He++N,, CO collisional systems in the same energy range. They have indeed shown that vibrational and vibronic excitations of the target molecule are partly due to perturbations of the ground-state potential energy surface at crossings with charge exchange or electronic excited Outgoing channels as well as to perturbations inherent in this surface itself, such as multipolar interactions (Dhuicq et al 1985, Dhuicq and Sidis 1986, Dhuicq 1990). In the latter paper a model has been used to describe the dependence of the vibrational excitation upon the molecular orientation and the scattering angle.…”

Section: Introductionmentioning

confidence: 99%

Vibrational excitation in proton-hydrogen collisions at medium energies

Dhuicq

Benoît

1991

J. Phys. B: At. Mol. Opt. Phys.

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The vibrational populations of H,(X 'Xi, 0) produced by Hf projectiles at energies 90s E s IOOOeV have been measured as a function of the scattering angle 9. A strang vibrational excitation is observed at large angler far all energies studied. Measurements of charge exchange and electronic excitation have also been performed in order to examine whether this vibrational excitation may be related to these processes. A relative increase o i the charge tranrier dirierentiai cross section is thus observed when the coilision energy increases. A simple model is tried to rationalize the variations with E and 8 of the vibrational excitation. A fairly good agreement between the experimental and theoretical results is obtained especially at low energy. The discrepancies found at higher energy may be explained in terms of interactions neglected in the model such as charge transfer and electronic excitation.

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Angular dependence of vibronic excitation in He⁺+CO, N₂collisions at medium energies: evidence for non-Franck-Condon and non-Poisson vibrational distributions

Cited by 12 publications

References 31 publications

Cross Sections and Reaction Rates of Relevance to Aeronomy

Cross Sections and Reaction Rates of Relevance to Aeronomy

Classical and semiclassical calculations of electron transfer cross sections inkeV-energy ion-molecule collisions

Vibrational excitation in proton-hydrogen collisions at medium energies

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Angular dependence of vibronic excitation in He++CO, N2collisions at medium energies: evidence for non-Franck-Condon and non-Poisson vibrational distributions

Cited by 12 publications

References 31 publications

Cross Sections and Reaction Rates of Relevance to Aeronomy

Cross Sections and Reaction Rates of Relevance to Aeronomy

Classical and semiclassical calculations of electron transfer cross sections inkeV-energy ion-molecule collisions

Vibrational excitation in proton-hydrogen collisions at medium energies

Contact Info

Product

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Angular dependence of vibronic excitation in He⁺+CO, N₂collisions at medium energies: evidence for non-Franck-Condon and non-Poisson vibrational distributions