Refractive lens based full-field x-ray imaging at 45-50 keV with sub-micron resolution

Combining sub-micron spatial resolution full-field-imaging with the penetration property of high-energy x-rays (> 50 keV) offers numerous applications, such as the ability to observe cracks and voids associated with the onset of failure in engineering materials, complementing x-ray diffraction microscopy probes. Progress in the development of adding such an imaging capability at the Advanced Photon Source high-energy x-ray undulator beamline 1-ID is reported. An initially tested, long baseline configuration had 18-21× x-ray image magnification with compound refractive lenses (as objective) placed 1.8 m after the specimen, and a two-dimensional detector located at a 32–37 m additional distance, in a different experimental station. Later, a more compact set-up of 3.5× magnification with a ≈6 m sample-to-detector separation, fitting within a single end-station, was tested. Both set-ups demonstrated 500 nm level spatial resolutions at energies within the 45–50 keV range. Phase contrast artifacts are present, and are discussed in view of the goal of achieving tomography capability, at even higher resolution, in such an instrument with high x-ray energies.