Diamond compound refractive lens tests with high-energy x-rays

Abstract

Diamond has low x-ray absorption relative to refractive strength and outstanding thermal properties, making it well-suited for refractive optics for high-power (white beam) and monochromatic synchrotron x-rays. In addition, single-crystal diamond offers the advantage of preserving beam coherence, exploiting that property of high-brilliance and ultra-low emittance new sources such as the multi-bend-achromat upgrade of the Advanced Photon Source (APS). The small curvature-radius, bi-concave, diamond compound refractive lenses (CRLs) presented here were fabricated by femtosecond-laser ablation followed by optional polishing. Focusing tests were conducted with high-energy x-rays (~50 keV) in a long focal length configuration at the APS 1-ID beamline. A convex CRL for beam expansion is also presented.