Vibrationally resolved study of the fourth photoelectron band of acetylene at 23.5 eV

Göthe, M. Carlsson; Chau, Foo‐Tim; Baltzer, P.; Svensson, S.; Wannberg, B.; Karlsson, Leif

doi:10.1016/0009-2614(90)80091-q

Cited by 11 publications

(4 citation statements)

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“…They also found that there exist three doubly excited states labelled D1, D2 and D3 as shown in figures 2(b) and (c) and the doubly excited D2 state is built on the (1t 2 ) −2 (3a 1 ) state of CH 4 + . Based on the above we conclude that (1) the 29.5 eV peak in figure 2 (Göthe et al 1991).…”

Section: Doubly Excited States Of Methane Produced By Photon Interactionmentioning

confidence: 54%

“…The vertical ionization potentials for the (1t 2 ) −1 , (2a 1 ) −1 and (1a 1 ) −1 states of CH 4 + are 14.5, 23.0 and 290.707 eV, respectively (Göthe et al 1991, Asplund et al 1985. The dissociation processes resulting in the formation of H(2p) and their dissociation limits are listed in table 1.…”

Section: Resultsmentioning

confidence: 99%

“…The photoelectron spectrum of CH 4 taken at a photon energy of 65 eV and an angle of 90 • against the electric vector of the incident polarized light (Göthe et al 1991) is shown in (d) since the ionic states of CH 4 have been substantiated much better than the neutral superexcited states in this range by means of photoelectron spectroscopy. The intense peak at 23 eV due to the (2a 1 ) −1 state in (d) is accompanied by the satellite peaks labelled 1-4, which are attributed to the double-hole one-electron states of CH + 4 , 1: the (1t 2 ) −2 (2t 2 ) state, 2: the (1t 2 ) −2 (3a 1 ) state, 3: the (2a 1 ) −1 (1t 2 ) −1 (2t 2 ) state, 4: the (2a 1 ) −2 (3a 1 ) state (Göthe et al 1991). Such double-hole one-electron states of CH 4 + are indicative of the neutral doubly excited states built on them.…”

Section: Doubly Excited States Of Methane Produced By Photon Interactionmentioning

confidence: 99%

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Doubly excited states of methane produced by photon and electron interactions

Fukuzawa¹,

Odagiri²,

Nakazato³

et al. 2005

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

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The formation and decay of doubly excited methane in photon and electron interactions have been investigated through measuring (i) the cross sections for the emission of the Lyman-α fluorescence in the photoexcitation of CH4 as a function of incident photon energy in the range 18–51 eV and (ii) the electron-energy-loss spectrum of CH4 tagged with the Lyman-α photons at 80 eV incident electron energy and 10° electron scattering angle in the range of the energy loss 20–45 eV. Five superexcited states have been found, three of which are doubly excited states with the others being singly excited states. It has been found that the electron interaction with CH4 at 80 eV incident electron energy and 10° electron scattering angle accelerates the double excitation against the single excitation as compared with the photon interaction.

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Section: Doubly Excited States Of Methane Produced By Photon Interactionmentioning

confidence: 54%

Section: Resultsmentioning

confidence: 99%

Section: Doubly Excited States Of Methane Produced By Photon Interactionmentioning

confidence: 99%

See 1 more Smart Citation

Doubly excited states of methane produced by photon and electron interactions

Fukuzawa¹,

Odagiri²,

Nakazato³

et al. 2005

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

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“…18 Of the authors that have addressed photoionization processes in this energy region 3,5,9,21,22 most have extended their analysis only as far as the A 2 ⌺ g ϩ threshold at ϳ16.3-17.0 eV. Above this energy, Göthe et al 23 and Wu and Judge 24 have specifically studied photoionization in the immediate threshold regions of B 2 ⌺ u ϩ and C 2 ⌺ g ϩ , respectively. The experimental photoionization spectrum for acetylene in the 16-25 eV region has a complex structure, and most experimental reports attribute the structure to ͑i͒ coarse and fine vibrational structure with only minor intensity variations from Rydberg states, and/or ͑ii͒ Rydberg states with only minor intensity variations from vibrational structure.…”

Section: Introductionmentioning

confidence: 96%

The outer valence photoionization of acetylene

Wells

Lucchese

1999

The Journal of Chemical Physics

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We report fixed-nuclei photoionization cross-sections and asymmetry parameters for photoionization leading to the X 2Πu, A 2Σg+, B 2Σu+, and C 2Σg+ states of acetylene with emphasis on the first four states. The magnitude of the photoionization cross-sections calculated here is in excellent agreement with recent experiment at both low and high photon energy. Further, as a result of the multichannel scattering methodology used to perform the calculation, the partial channel cross-sections and asymmetry parameters reported here resolve significant structure arising from indirect photoionization processes such as autoionization. Although vibrational degrees of freedom are not included within the fixed nuclei framework employed here, we find that, even without vibrational degrees of freedom, the present theoretical results generally exhibit the same detailed features as the experimental results, both for conventional photoionization spectra and, as a result of vibrational autoionization, for threshold photoionization spectra. This general agreement suggests that a large part of the structure in the low energy or outer valence photoionization spectrum of acetylene is explicable solely in terms of Rydberg transitions. This study also predicts that dark states may cause some appreciable distortion of the profile of the photoionization asymmetry parameter in the photon region of ∼20–21.5 eV as a result of final state correlations with more intense states.

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