Detailed diffraction imaging of x-ray optics crystals with synchrotron radiation.

Abstract

Rocking curve topography at the Advanced Photon Source s beamline 1-BM measures the x-ray reflection from large (many cm2) flat crystals on a sub-mm scale with microradian angular resolution. The (011̄1) reflection at 8 keV is uniform across the crystal and close to theory for three thick quartz wafers well-polished with increasingly finer grit. However, the reflection is non-uniform for some ∼0.1 mm thin, bendable crystals that are made flat by optical contact with a flat substrate. These thin crystals are bent to serve in certain x-ray diagnostics of plasmas, and similar non-uniformities could then occur in bent crystals as well. The same detail in x-ray reflection in bent crystals is unachievable with the existing topography setup: One way to get the desired resolution is with a standard microfocusing approach.