LNLS, Campinas, Brazil
Brazil is building Sirius, the new Brazilian synchrotron light source which will be the largest scientific infrastructure ever built in Brazil and one of the world's first 4th generation light laboratory. Mogno, the future X-ray nano and microtomography beamline is being designed to execute and process experiments in only few seconds. For this reason, prototypes and automated systems have being tested and implemented in the current Brazilian Synchrotron Light Laboratory (LNLS) imaging beamline (IMX). An industrial robot was installed to allow fast sample exchange through an easy-to-use graphical user interface. Also, scripts using Python and Experimental Physics and Industrial Control System (EPICS) were implemented for automatic sample alignment, measurement and reconstruction. In addition, a flow cell for study dynamics and behaviour of fluids at the rock pore scale in time resolved experiments (4D tomography) is being projected.
LNLS, Campinas, Brazil
Three-dimensional image reconstruction in X-ray computed tomography (XRCT) is a mathematical process that entirely depends on the alignment of the object of study. Small variations in pitch and roll angles and translational shift between center of rotation and center of detector can cause large deviations in the captured sinogram, resulting in a degraded 3D image. Most of the popular reconstruction algorithms are based on previous adjustments of the sinogram ray offset before the reconstruction process. This work presents an automatic method for shift and angle adjust of the center of rotation (COR) before the beginning of the experiment removing the need of setting geometrical parameters to achieve a reliable reconstruction. This method correlates different projections using Scale Invariant Feature Transform algorithm (SIFT) to align the experimental setup with sub-pixel precision and fast convergence.