Focusing Optics for High-Energy X-ray Diffraction

Abstract

Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40-100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved by a bent multilayer arranged behind the crystal monochromator and alternatively by a bent Laue crystal. A 1.2 micro m-high line focus was obtained at 90 keV. The properties of the different set-ups are described and potential applications are discussed. First experiments were performed, investigating with high spatial resolution the residual strain gradients in layered polycrystalline materials. The results underline that focused high-energy synchrotron radiation can provide unique information on the mesoscopic scale to the materials scientist, complementary to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy.

Microbeam small-angle scattering experiments and their combination with microdiffraction

“…(Bilderback, Hoffman & Thiel, 1994;Iida &.Hirano, 1996Cedola, Lagomarsino, Di Fonzo, Jark, Riekel & Deschamps, 1998, diffraction e.g. (Lienert, Schulze, Honkimaeki, Tschentscher, Garbe, Hignette, Horsewell, Lingham, Poulsen, Thomsen & Ziegler, 1998) and refraction (Snigirev, Kohn, Snigireva & Lengeler, 1996) principles. A beam of 50 nm has been obtained by glass capillary optics (Bilderback, Hoffman & Thiel, 1994).…”

Strain tensor determination of compressed individual silica sand particles using high-energy synchrotron diffraction

“…It is based on transmission geometry that can be applied in both layered and bulk materials [23][24][25][26][27]. It allows nondestructive 3D mapping of polycrystalline materials and monitors in situ dynamic processes of the bulk specimens.…”

The 3DXRD Microscope

“…The first is an asymmetrically cut and bent crystal of perfect Si, used in transmission mode (a Laue crystal) [5]. The second is an elliptically shaped, laterally graded multilayer (ML), used in reflection mode at a glancing angle [3]. The ML is made of W and B 4 C. Both elements provide focusing in one dimension.…”