Calibration Protocol for Zoom Tomography Experiments at the MOGNO Beamline Nano-Station

Abstract Sirius is a fourth-generation synchrotron light source located in Campinas, Brazil. The MOGNO beamline facilitates material structure analysis through micro and nano-tomography. This beamline employs a conical X-ray beam that enables variable image resolution by moving the sample along the beam path, thus allowing for zoom tomography. In this experiment, the sample is initially imaged at low resolution, followed by reconstruction analysis to identify a new region of interest (ROI) for higher-resolution imaging. The MOGNO’s nano-station sets the sample position at the selected ROI. Therefore, this work presents a calibration protocol for enhancing zoom tomography experiments by ensuring that the rotation axis and ROI height remain aligned with the detector’s center during zoom-in operations. This calibration is critical not only for guaranteeing accurate imaging of the selected area but also for optimizing state-of-the-art reconstruction algorithms that combine high- and low-resolution images to enhance the quality of zoomed 3D tomography data.