EXPLORE ESRF BEAMLINES - BM26: DUBBLE SAXS / WAXS Beamline - Dipanjan Banerjee - Martin Rosenthal

BM26: DUBBLE SAXS/WAXS Beamline
Abstract

Dipanjan Banerjee and Martin Rosenthal

The DUBBLE BM26 beamline at the ESRF provides small angle x-ray scattering (SAXS) and wide-angle x-ray scattering (WAXS) techniques to the European and Flemish user communities. This facility offers information on the structure and structural changes over a wide range of time (from ms to hours) and lengths scales (from the atomic scale to 500 nm). Traditionally the beamline is optimized for soft condensed matter research, but has successfully shown its capacity in other fields as well. The beamline operates at photon energies in the range from 8 to 20 keV. The scattering and diffraction signals are recorded using photon counting area detectors, e.g. Pilatus 1M & Pilatus 300K-W. Under standard conditions, the beam at the sample measures 300 μm² but for specific purposes, the beamline also offers a microfocused (40 μm²) X-ray beam using compound refractive lenses (CRL). Such a beam is ideally suited to probe structures within μm sized samples or for the spatial mapping of hierarchically organized matter. The beamline is equipped with an in-line microscope for precise beam positioning. For the study of surfaces and thin films, grazing incidence GISAXS and GIWAXS are available. This permits studying morphological developments, nanopatterning and self-assembly processes in thin films and surfaces, in both time-resolved and in-situ. BM26 offers a multitude of sample environments including heating and tensile stages, shear cell, DSC, flow cells, cryostream and magnetic fields. In addition, the beamline can accommodate a large variety of user equipment for sample conditioning and in-situ experimentation due to its flexible design of the experimental setup such as a fast scanning chip calorimeter, equipment for atomic layer deposition, extruders, high pressure cells, spin coaters, etc. The main strength of the beamline is its ability to probe material structure in-situ while the materials are processed, perform or when being exposed to environmental changes. At the same time relevant properties are probed in terms of heat flows, mechanical, rheological, optical or chemical parameters. At present x-ray absorption spectroscopic (XAS) methods are not available at BM26 but will be installed in the near future. BM26 will offer Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES), providing information about the oxidation state, electronic structure, and the local coordination environment of the absorbing atom. In addition, a polycapillary based beam focusing system is available, which in a confocal detection setup allows three dimensional mapping of the elemental composition and chemical state at a resolution of approximately 10 μm.