| 1. |
- Ueda, K, et al.
(författare)
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Nuclear motion and symmetry breaking of the B 1s-excited BF3 molecule
- 2003
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Ingår i: Chemical Physics. - 0301-0104. ; 289:1, s. 135-147
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Tidskriftsartikel (refereegranskat)abstract
- Out-of-plane nuclear motion stimulated in the core-excited state and symmetry breaking due to this nuclear motion have been investigated for B Is excitation in the BF3 molecule by a combination of three different experimental methods: angle-resolved ion-yield spectroscopy, vibrationally resolved resonant Auger electron spectroscopy and quadruple-ion coincidence momentum-imaging technique. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 2. |
- Baev, A., et al.
(författare)
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Doppler interference in dissociative resonant photoemission
- 2002
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 66:2
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Tidskriftsartikel (refereegranskat)abstract
- Resonant photoemission involving dissociative core excited states has been the subject of a great number of experimental and theoretical investigations in recent time. The resonant decay of such dissociating systems has been shown to lead to semiatomic Auger electron emission spectra, with particular angular behavior. In the present paper a detailed theoretical analysis of dissociative resonant photoemission spectra of homonuclear diatomic molecules is presented. The theory addresses both fixed in space and randomly oriented homonuclear molecules and emphasizes the Doppler effect and the role of the interference between channels referring to the Doppler split atomic fragments. It is shown that peaks originating from decay in the atomic fragments can be asymmetric and structured due to the Doppler interference effect. The predicted strong non-Lorentzian behavior of the substructure on the top of the Doppler broadened atomiclike contribution is traced to the interplay between decay channels leading to gerade and ungerade final states. Simulations based on wave-packet theory are compared with experimental data for molecular oxygen. Our numerical simulations of the atomiclike resonance of fixed in space molecules show that the spectral profile is very sensitive to the shape of interatomic potentials of core excited and final states. It is shown that the Doppler effect in the decay spectra depends upon the symmetry of the core excited state.
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| 3. |
- Kitajima, M., et al.
(författare)
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Doppler effect in resonant photoemission from SF6 : Correlation between doppler profile and auger emission anisotropy
- 2003
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 91:21
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Tidskriftsartikel (refereegranskat)abstract
- Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.
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| 4. |
- Feifel, R, et al.
(författare)
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Probing doubly excited ionic states of N-2(+) via a triple excitation above the N 1s threshold in the N-2 molecule
- 2003
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 67:3: 032504
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Tidskriftsartikel (refereegranskat)abstract
- Angle-resolved resonant Auger-electron spectroscopy has been carried out on the nitrogen molecule at selected photon energies around 419 eV, where a 1s core electron and two valence electrons are promoted into the lowest unoccupied molecular orbital 1pi(g). Significant enhancement of a specific band, which cannot be disentangled in direct photoionization, is observed at a binding energy of 37.6 eV, with a value of the anisotropy parameter beta much smaller than 2. We assign this new band to the transition to a doubly excited cationic state of N-2, in which two of the excited valence electrons remain in the 1pi(g) orbital, proposing a "double spectator" type decay mechanism. This observation shows how to preferentially probe multiply excited configurations of cations using multiple resonant excitation.
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| 5. |
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| 6. |
- R. Feifel, K. Ueda, A. De Fanis, K. Okada, S. Tanimoto, T. Furuta, H. Shindo, M. Kitajima, H. Tanaka, O. Björneholm, L. Karlsson, S. Svensson and S. L. Sorensen
(författare)
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Probing doubly excited ionic states of N2+ via a triple excitation above the N1s threshold in the N2 moecule
- 2003
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Ingår i: Phys. Rev.. ; A:67, s. 32504-
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Ristinmaa Sörensen, Stacey, et al.
(författare)
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Application of an atomic relaxation model for the interpretation of O1s to Rydberg excited Auger electron spectra of molecular oxygen
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 398:1-3, s. 168-174
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Tidskriftsartikel (refereegranskat)abstract
- Resonant and normal Auger electron spectra associated with an O1s initial vacancy of the O-2 molecule have been recorded using photon energies of 541.80, 541.97 and 650 eV. The resonant Auger spectra obtained at 541.80 and 541.97 eV are interpreted as composed essentially of two characteristic parts, one between 10 and 35 eV binding energy reminiscent to direct photoionisation, and another, above 35 eV, associated primarily with spectator decay of the intermediate core-hole state. The spectra above 35 eV owe some similarity to the ordinary Auger electron spectrum recorded at 650 eV, and an interpretation is made in terms of Rydberg series in the cation converging towards the dicationic ionisation limits. The interpretation is based on a relaxation model introduced earlier for atomic resonant Auger spectra. The assignments of the resonant spectra assume that the relevant intermediate neutral states at 541.80 and 541.97 eV governing the Auger decay are essentially the v = 0 and 1 vibrational components of the (O1s) ((4)Sigma(u)(-)) 4psigma Rydberg state. Arguments for this interpretation are given.
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| 8. |
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| 9. |
- Ueda, K, et al.
(författare)
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Anisotropic ultrafast dissociation probed by the Doppler effect in resonant photoemission from CF4
- 2003
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Ingår i: Physical Review Letters. - 1079-7114. ; 90:23: 233006
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Tidskriftsartikel (refereegranskat)abstract
- The resonant Auger spectrum from the decay of F 1s-excited CF4 is measured. Several lines exhibit a nondispersive kinetic energy as the exciting photon energy is tuned through the resonance region. The F 1s(-1) atomiclike Auger line is split into two components due to the emission of Auger electrons by a fragment in motion, when electron emission is observed along the polarization vector of the light. This Doppler splitting is direct evidence that the core excitation leads to T-d-->C-3v symmetry lowering, by elongation of a specific C-F bond preferentially aligned along the polarization vector of the incident photon.
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