title: Coherent small-angle scattering on a bending-magnet beamline at the ESRF.
abstract: A coherent X-ray beam is obtained from the D2AM bending-magnet beamline (BM2) of the European Synchrotron Radiation Facility. As this line has permanent convergent optics, monochromated by an Si(111) double monochromator, coherence conditions are satisfied by selecting a part of the beam close to the focal point. Low intensity (10(6) X-rays s(-1)) is partially compensated by a high degree of coherence and by the use of a high-resolution direct-illumination CCD area detector. The stability of the small-angle set-up makes quantitative analysis possible. The calculated and measured degrees of coherence are compared. The distributions of speckle intensities are explained by a beam composed of two-thirds coherent and one-third incoherent parts. This incoherent component is caused by Kapton windows, which will be removed in future experiments.
authors: LTPCM-ENSEEG, UMR-CNRS/INPG/UJF No. 5614, BP 75, 38402 St Martin d'Heres, France.
authors: F
authors: F
authors: Livet
authors: F
authors: F
authors: Bley
authors: A
authors: A
authors: Létoublon
authors: J P
authors: JP
authors: Simon
authors: J F
authors: JF
authors: Bérar