A SMALL-ANGLE X-RAY SCATTERING STATION AT BEIJING SYNCHROTRON RADIATION FACILITY

This article presents the development and current state of a small-angle X-ray scattering station at beamline 1W2A of the Beijing Synchrotron Radiation Facility, China. The source of the beamline is introduced from a 14-pole wiggler. A triangular bending Si(111) crystal is used to horizontally focus the beam and provide a monochromatic X-ray beam (8.052keV). A bending cylindrical mirror coated with rhodium downstream from the monochromator is used to vertically focus the beam. The X-ray beam is focused on the detector which is fixed at 30m from the source. The focused beam size (full width at half maximum) is 1.4x0.2mm(2) (horizontalxvertical) with a flux of 5.5x10(11) phs/s at 2.5GeV and 250mA. Besides the routine mode of small-angle X-ray scattering, the combination of small- and wide-angle X-ray scattering, grazing incidence small-angle X-ray scattering, and time-resolved small-angle X-ray scattering in sub-second level are also available for the users. Dependent on the measurement requirements, several detectors can be chosen for the collection of scattering signals. Furthermore, multiple sample environments, including temperature, stress-strain, and liquid sampling are available for in situ measurements. In a typical camera length of 1.5m, the small-angle X-ray scattering resolution is about 115nm. The steady operation of the small-angle X-ray scattering station at Beijing Synchrotron Radiation Facility not only provides the small-angle X-ray scattering beam time for users, but also promotes the development and application of these techniques in China.