Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MO: Molekülphysik
MO 8: Photoelektronenspektroskopie, Photodissoziation
MO 8.2: Vortrag
Donnerstag, 27. März 2003, 14:15–14:30, B 305
Interference quenching of ν” = 1 vibrational line in resonant photoemission of N2: a possibility to obtain geometrical information on the core-excited state — •Raimund Feifel — P. O. Box 530, S-752 21 Uppsala, Schweden
Resonant Auger electron spectroscopy has been performed on the N2 molecule for N1s → π* core-excitation in the so-called No-dqRaman modeNo-dq, where the photon energy bandwidth was considerably smaller than the natural lifetime width of the core-excited state under consideration. An interference quenching of the ν” = 1 vibrational line of the X2Σg+ singly-ionized final state has been observed and analyzed. The intensity ratio between the ν” = 1 and ν” = 0 vibrational levels of the X2Σg+ final state shows a surprising non-monotonous variation as a function of frequency detuning, going through a minimum with an almost complete suppression of ν” = 1. We have developed a simple model which indicates a linear relation between the value of the detuning frequency for this minimum and the equilibrium bond distance Rc0 of the core-excited state. This implies that this observation opens up a new possibility of determining the equilibrium bond distance for the core-excited state with a precision δ Rc0 < 10−3 [1,2]. The observation of such a minimum shows in particular that there is a direct relation between the molecular geometry and the experimentally measureable intensities in resonant Auger Raman spectra.
References:
[1] R. Feifel et. al. Phys. Rev. Lett. 89, 103002-1, 2002.
[2] A. Baev et. al. Phys. Rev. A, to be published.