A New Small-Angle X-ray Scattering Instrument on the French CRG Beamline at the ESRF Multiwavelength Anomalous Scattering/Diffraction Beamline (D2AM)

A new small-angle X-ray scattering instrument has been set up on the D2AM-ESRF beamline. This modular instrument, which has the capacity to handle different sample environments (variable temperature and pressure), is designed for easy wavelength changes, i.e. for anomalous-scattering studies. This paper describes its design and discusses in some detail its positioning and alignment with respect to the focusing optics. The mirrors were found to be a major source of diffuse scattering, which was eliminated by rearrangement of the slit positions and refocusing of the optics. The present configuration yields a high flux (10¹⁰photons s^-1) and allows measurements down to q = 0.005 Å^-1.