Circularly Polarized X Rays: Another Probe of Ultrafast Molecular Decay Dynamics

Abstract

Dissociative nuclear motion in core-excited molecular states leads to a splitting of the fragment Auger lines: the Auger-Doppler effect. We present here for the first time experimental evidence for an Auger-Doppler effect following F1s → a(1g)* inner-shell excitation by circularly polarized x rays in SF(6). In spite of a uniform distribution of the dissociating S-F bonds near the polarization plane of the light, the intersection between the subpopulation of molecules selected by the core excitation with the cone of dissociation induces a strong anisotropy in the distribution of the S-F bonds that contributes to the scattering profile measured in the polarization plane.

Intramolecular electron diffraction in vibrationally resolvedK-shell photoionization of methane

“…The new measurements have been carried out at the PLEIADES beamline (10-1000 eV) dedicated to ultrahigh resolution spectroscopic studies of isolated species [33][34][35][36] at the 2.75 GeV French national synchrotron radiation laboratory SOLEIL. The quasiperiodic Apple II elliptical undulator of 80 mm period (HU80) has been used to generate arbitrarily tilted linearly polarized light.…”

K-shell photoionization of O4 +and O5 +ions: experiment and theory

“…The present measurements were made using the MAIA (multianalysis ion apparatus) setup permanently installed on branch A of the PLEIADES beam line [27,28] at SOLEIL. The setup and the experimental procedure are the same as the ones described in our previous paper on the O 3+ ion [9] and have already been detailed in [29].…”

Electron spectroscopy using ultra brilliant synchrotron X-ray sources

“…For example, when considering a homonuclear diatomic molecule like O 2 , the kinetic energies of the electrons emitted from an atom moving towards the detector are blue-shifted while the kinetic energies of the ones from an oxygen atom moving away from the detector are redshifted [69]. Such a "Doppler labeling" of the electrons have also been observed in other systems than diatomic molecules [70,71].…”