Speaker: Catalin MIRON, Synchrotron SOLEIL
Program Description
SOLEIL is the 2.75 GeV national French 3rd generation synchrotron radiation (SR) facility in operation since 2007 in Saint-Aubin, South of Paris. Twenty beamlines are already open to users and cover the IR to the hard X-ray energy range. In addition to conventional SR uses, special emphasis has been put to ultrahigh resolution studies of isolated species (FT spectroscopies in the IR and VUV, sub-lifetime spectroscopies in the soft x-rays), imaging (IR and UV microscopy, spectromicroscopy, and nanospectroscopy, tomography), and time resolved techniques (time resolved photoemission and diffraction etc.).
Since many years, electron spectroscopy is an excellent analytical tool to characterize material’s chemical composition or degree of oxidation. When performed at ultra-high resolution inner-shell spectroscopies provide an accurate probe of ultrafast (fs) decay dynamics, in particular for isolated species. Completely new scientific opportunities are being offered by the bright and highly monochromatic x-ray beams coupled to state-of-the-art instrumentation, such as the PLEIADES beamline, operated as a user facility since March 2010.
Selected examples will be shown from a wide panel of cases where high-resolution spectroscopies have been employed to investigate fundamental properties of matter, such as the Vibrational Scattering Anisotropy (VSA), the Auger-Doppler effect using circularly polarized light, or the rotational Doppler broadening of molecular electron spectra. Very recently, we have shown that ultrahigh resolution resonant photoemission can be applied to molecular potentials’ imaging, that photoionization cross sections cannot be always related to stoichiometry in a simple way, and that electron spectroscopy can be used as a fine probe of nano-objects’ chemical composition (energy) and size (angular distribution).
