X-RAY-DIFFRACTION OF BENT CRYSTALS IN BRAGG GEOMETRY .2. NONIDEALLY IMPERFECT CRYSTALS, MODELING AND RESULTS

Abstract

An earlier model for finite curved perfect crystals is extended to the non-ideally imperfect regime, allowing for mosaic structure from dislocations, vacancies or phase boundaries. Effects of Johann crystal mounting and depth penetration in the Bragg geometry are included. The model estimates diffraction shifts for mosaic crystals with regular local structure. Integrated reflectivities, diffraction widths, shifts and profiles against several parameters demonstrate agreement with the earlier model as an extreme and hence agreement with the literature. The theory is applied to first- and fourth-order spectra in differential quantum electrodynamic (QED) measurements and to pentacrythritol 002 c..