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Struktur und Dynamik Poster: Mi., 14:00–16:30 M-P125
Lifetime vibrational interference effects observed in the NO + (A 1 Π → X 1 Σ + )
fluorescence after 1s −1 π ∗ resonance excitation
Arno Ehresmann 1 , Lutz Werner 1 , Ph. V. Demkhin 2 , M. P. Lemeshko 2 , V. L.
Sukhorukov 2 , Karl-Heinz Schartner 3 , Hans Schmoranzer 4
1 Institute of Physics, University of Kassel, D-34132 Kassel, Germany – 2 Rostov State
University of Transport Communications, 344038 Rostov-on-Don, Russia – 3 I Institute
of Physics, Justus-Liebig-University Giessen, D-35392 Giessen, Germany –
4 Department of Physics, Kaiserslautern University of Technology, D-67653 Kaiser-
slautern, Germany
Fluorescence spectroscopy experiments on simple molecules after excitation by monochromatized
synchrotron radiation were mainly focused on outer-shell excitations of molecules
(e.g. [1-3]), whereas the decay of inner shell excitations was investigated only scarcely
(see e.g. [4]). The excitation of an inner shell electron in a molecule induces very
complex relaxation processes, which are governed by the competition between autoionization
and fragmentation of the molecule. In the present work we investigated aspects
of the decay of the 1s −1 π ∗ resonances of NO by fluorescence spectroscopy, measuring
dispersed VUV-fluorescence intensities (118 nm≤ λfl ≤ 143 nm) to investigate the
influence of liftime vibrational interference (LVI).
In recent studies we successfully investigated the C(v ′ ) → X(v ′′ ) fluorescence in the
N +
2 ion excited via the 1s−1π ∗ resonance [5-6]. Due to the vibrational spacing of the
N ∗ 2 state of about 230 meV, which is about twice as large than its natural linewidth the
LVI between the excitation pathways via different 1s −1 π ∗ (vr) vibrational levels was
found to be not of significance. In contrast the vibrational spacing of 195 meV of the
N ∗ O state is only about 1.5 times larger than its natural width and in the case of the
NO ∗ the vibrational spacing is already smaller than the natural width. For the N ∗ O
state LVI effects has been observed by [7] and it is expected that a very pronounced
vibrational interference will be investigated in the case of the NO ∗ de-excitation.
[1] H. Liebel et al. J. Phys. B: At. Mol. Opt. Phys. 35 (2002)
[2] Y. Hatano Phys. Rep. 313 (1999)
[3] E. D. Poliakoff Vacuum Ultraviolet Photoionization and Photodissociation of Molecules
and Clusters edited by Ng C Y (World Scientific, Singapore)(1991)
[4] A. Marquette et al. Phys. Rev. A 35 (2000) 022513
[5] A. Ehresmann et al. J. Phys. B: At. Mol. Opt. Phys. 39 (2006) 283
[6] A. Ehresmann et al. J. Phys. B: At. Mol. Opt. Phys. 39 (2006) L119
[7] T. X. Carroll et al. Phys. Rev. Lett. 58(9) (1987) 867