Detection of the standing X-ray wavefield intensity inside a thin crystal using back-diffraction topography and imaging

The standing X-ray wavefield into a single-crystal bulk is characterized by a combination of the diffracted-reflected h-beams and the diffracted-transmitted o-beam. For different angular positions on the total reflection region, the standing X-ray wavefield has its maximum from the region between the atomic planes (low photoelectric absorption) to the region on the atomic planes (high photoelectric absorption). Historically, the evidence for such a characteristic has come from experiments such as anomalous transmission (Borrmann effect, originally detected in Laue geometry) and fluorescent measurements with a single crystal under diffraction conditions. In the present work, such a characteristic is demonstrated by the direct measurement of the standing X-ray wavefield intensity into a 50 µm-thick single-crystal CCD detector (Si 800) set in back-diffraction geometry.