Doppler effects in resonant x-ray Raman scattering
1998 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 57, no 4, 2511-2526 p.Article in journal (Refereed) Published
Theory for Doppler effects in resonant x-ray Raman scattering (RXS) is presented. It is shown that the "electron" Doppler effect is important in nonradiative RXS for decay transitions between continuum nuclear states lying above the dissociation threshold, and that the averaging of the RXS cross section over molecular orientations can lead to strong non-lorentzian broadenings of the atomiclike resonances. The Doppler effect is found to give a unique possibility to distinguish dissociating identical atoms, because different peaks correspond to atoms with opposite Doppler shifts. Spectral features of the atomiclike profile are predicted and analyzed. Strong oscillations of the RXS cross section will occur as a consequence of the interference of the Auger electrons. Due to the Doppler effect and the interference, the atomiclike profile can be associated with supernarrow spectral features, the width of which goes below the lifetime broadening and is practically independent of the spectral distribution of the incident radiation. As another consequence of the oscillations and strong anisotropy caused by the interference, we predict parity selection rules for Auger decay transitions in both bound and dissociative systems. The corresponding experiments can be realized by measurements of resonant Auger of surface adsorbed molecules and for molecules by the electron-ion coincidence technique.
Place, publisher, year, edition, pages
1998. Vol. 57, no 4, 2511-2526 p.
PHOTOELECTRON-SPECTROSCOPY, EMISSION-SPECTROSCOPY, ORIENTED MOLECULES, SPECTRA
Atom and Molecular Physics and Optics Physical Sciences
IdentifiersURN: urn:nbn:se:kth:diva-13839ISI: 000073243700038OAI: oai:DiVA.org:kth-13839DiVA: diva2:327677
QC 201006302010-06-302010-06-302010-06-30Bibliographically approved