A laboratory transmission diffraction Laue setup to evaluate single‐crystal quality

• Published in: Journal of applied crystallography 2020-08, Vol.53 (4), p.914-926
• Main Authors: Arnaud, Alexiane, Guediche, Wijdène, Remacha, Clément, Romero, Edward, Proudhon, Henry
• Format: Article
• Language: English
• Subjects: Algorithms; Collimation; Computer simulation; Diffraction; Evaluation; extended samples; high‐energy X‐rays; indexing algorithms; Laboratories; laboratory setups; lattice curvature; Laue patterns; Laue transmission diffraction; Mapping; Mechanics; Mechanics of materials; Misalignment; orientation mapping; Physics; Scanning; Tensors
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S1600576720006317

A scanning laboratory Laue transmission setup is developed to probe extended quasi‐monocrystalline samples. Orientation mapping is achieved by controlling the collimation of the incident beam and scanning the position of the specimen. An automated indexing algorithm for transmission Laue patterns is presented, together with a forward simulation model adapted for a laboratory setup. The effect of the main parameters of the system is studied with the aim of achieving exposure times of the order of one second. Applications are presented to probe the orientation of an extended part and detect disoriented regions within the bulk. Finally, the analysis of diffraction spot shapes shows that the misorientation within the illuminated volume can be measured, and a new method is proposed to evaluate its complete mean lattice rotation tensor. A laboratory Laue transmission setup has been developed to evaluate single‐crystal quality in extended specimens. The method combines a compact high‐energy setup, a general indexing algorithm and a forward model. Orientation mapping and parasite grain detection can be achieved by scanning a part in the plane perpendicular to the beam.