Characterization of Pt-coated twin paraboloidal laboratory capillary high energy X-ray optics.

Novel focusing optics composed of twin paraboloidal capillaries coated with Pt, for laboratory X-ray sources are presented and characterized. The optics are designed to focus the X-rays, resulting in an achromatic focused beam with photon energies up to 40 keV. The performance of the optics under different operational conditions is studied by comparing the energy-photon count spectra of the direct and focused beams. Based on these analyses, the optics gain and efficiency as a function of photon energy are determined. A focal spot of 8.5 µm with a divergence angle of 0.59° is observed. The obtained characteristics are discussed and related to theoretical considerations. Moreover, the suitability and advantages of the present optics for X-ray microdiffraction is demonstrated using polycrystalline aluminium. Finally, possibilities for further developments are suggested.