A comparative study of X-ray absorption spectroscopy at various synchrotron facilities and the effect of transverse source coherence

Core level X-ray Absorption Spectroscopy measurements have been performed at the L-3,L-2 edges of thin film Fe samples deposited on the (100) surface of Cu. Soft X-rays from five different beamlines have been used to measure spectra from identical samples with very different degrees of transverse coherence in the synchrotron radiation. The degree of source coherence has been characterised by diffraction. The transverse coherence length has been extracted and found to be on the mum length scale at certain beamlines. An increase of the L edge resonance intensities, relative to the continuum states, is observed in spectra measured at these beamlines. (C) 2000 Elsevier Science B.V. All rights reserved.