Journal article
Large impact of the weak direct photoionization on the angularly resolved CO⁺(A ²Π) de-excitation spectra of the CO*(1σ⁻¹2π) resonance
Publication Details
Authors: | Demekhin, P.; Petrov, I.; Tanaka, T.; Hoshino, M.; Tanaka, H.; Ueda, K.; Kielich, W.; Ehresmann, A. |
Publication year: | 2010 |
Journal: | Journal of Physics B: Atomic, Molecular and Optical Physics |
Pages range : | 065102 |
Volume number: | 43 |
ISSN: | 0953-4075 |
DOI-Link der Erstveröffentlichung: |
Abstract
Interference between the direct and resonant amplitudes for the population of the CO+(A 2Π) state in the vicinity of the O 1s → 2π excitation of CO* is studied by an ab initio theoretical approach. The weak direct photoionization induces Fano-Shore-type profiles resulting in long-range exciting-photon energy dependences of the computed angular distribution parameters for the CO+(A 2Π) photoelectrons, βeA(ω), and for the subsequent CO+(A 2Π → X 2Σ+) fluorescence, β2XA(ω). In the presence of direct photoionization, the lifetime vibrational interference causes substantial variations of the computed parameter βeA(ω) across the positions of the CO*(vr) vibronic states. Theoretical results are in qualitative agreement with the vibrationally and angularly resolved CO+(A 2Π) resonant Auger electron spectra recorded in the Raman regime at different exciting-photon energies across the CO* resonance.
Interference between the direct and resonant amplitudes for the population of the CO+(A 2Π) state in the vicinity of the O 1s → 2π excitation of CO* is studied by an ab initio theoretical approach. The weak direct photoionization induces Fano-Shore-type profiles resulting in long-range exciting-photon energy dependences of the computed angular distribution parameters for the CO+(A 2Π) photoelectrons, βeA(ω), and for the subsequent CO+(A 2Π → X 2Σ+) fluorescence, β2XA(ω). In the presence of direct photoionization, the lifetime vibrational interference causes substantial variations of the computed parameter βeA(ω) across the positions of the CO*(vr) vibronic states. Theoretical results are in qualitative agreement with the vibrationally and angularly resolved CO+(A 2Π) resonant Auger electron spectra recorded in the Raman regime at different exciting-photon energies across the CO* resonance.
