Influence of Mechanical Damage to an Interferometer Block on Its X-Ray Diffraction Pattern

Abstract

This study examines the impact of mechanical damage to an X-ray interferometer block on its observed X-ray diffraction pattern. The origin of contrast resulting from imperfections in the crystal structure of the interferometer block, which arises from mechanical damage, is interpreted. Both theoretical and experimental evidence demonstrates that the curvature of interference fringes in the Moiré topogram is a result of scratches on the surface of the crystal block of the X-ray interferometer. The study determines the relationship between the period of the Moiré fringes, dislocation density, and their displacement. The average dislocation density near the center of the scratch is calculated. The study shows that the period of the Moiré pattern is inversely proportional to the dislocation density. Experimental evidence demonstrates that changes in the Moiré pattern also occur in the presence of dislocations in the crystal, which form as a result of a scratch on the surface of the crystal block of the X-ray interferometer. The geometric parameters of the scratch on the surface of the interferometer’s crystal block are determined. The depth of the scratch and the extent of the dislocation group aligned along the scratch are calculated.