Investigations of single fragile objects manipulated by optical forces with high brilliance X-ray beams may initiate the development of new research fields such as protein crystallography in an aqueous environment. We have developed a dedicated optical tweezers setup with a compact, portable, and versatile geometry for the customary manipulation of objects for synchrotron radiation applications. Objects of a few micrometers up to a few tens of micrometers size can be trapped for extended periods of time. The selection and positioning of single objects out of a batch of many can be performed semi-automatically by software routines. The performance of the setup has been tested by wide-angle and small-angle X-ray scattering experiments on single optically trapped starch granules, using a synchrotron radiation microbeam. We demonstrate here for the first time the feasibility of microdiffraction on optically trapped protein crystals. Starch granules and insulin crystals were repeatedly raster-scanned at about 50 ms exposure/raster-point up to the complete loss of the structural order. Radiation damage in starch granules results in the appearance of low-angle scattering due to the breakdown of the polysaccharide matrix. For insulin crystals, order along the densely packed [110] direction is preferentially maintained until complete loss of long-range order.
We report the development of a 3D positioner for the elemental mapping of non-flat surfaces of heritage targets and its implementation in the external beam of the AGLAE accelerator, a joint research activity of the IPERION-CH European program.The positioner operates in two steps: 1) object surface is digitized using a 3D scanner implemented in the beamline. Surface points are interpolated onto a rectangular grid suitable for beam scanning. 2) Object is scanned under the beam using X/Y/Z stages holding a hexapod robot for rotations. During scanning, target surface is positioned with the Z stage and oriented perpendicular to the beam using hexapod rotations. Areas up to 100 × 100 mm 2 with a resolution of 50 µ m and 30° curvature of can be mapped on objects of 200 mm and 5 kg max. System operation was tested by recording PIXE maps on the polychrome decoration of a curved porcelain pot.
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