Faster and targeted raster imaging through non-rectangular scanning

Many materials are spatially heterogenous and it is important to characterize this heterogeneity, which can be done by scanning microbeam X-ray diffraction (µXRD) or X-ray fluorescence (µXRF) microscopy. A modified approach to raster scanning is presented, where each line in a raster scan is of varying length, allowing for efficient scanning of non-rectangular areas. This shortens the measurement time significantly and similarly reduces the large amount of data generated from the area outside the sample that is normally produced for non-rectangular samples. The scanning procedure has been implemented for µ-X-ray diffraction and fluorescence mapping at the DanMAX diffraction beamline at MAX IV, Sweden. It was found that the reduction in required measurement time was nearly proportional to the reduction in scanned area, a significant reduction for non-rectangular samples. As an example, a section of the dactyl club of a stomatopod specimen (Odontodactylus scyllarus) was scanned.