Afterglow artifacts correction for ultra-fast tomography acquisition by synchrotron radiation

The availability of synchrotron-generated high-flux and high-energy x-rays has significantly reduced the acquisition time a tomographic scan which allows following dynamic processes in 4D (3D space + time). In the ultra-fast endstation usually a scintillator is used to convert X-ray to visible photons that can be detected by the camera. However, this conversion is not ideal and the scintillator decays exponentially with afterglow. Afterglow can cause resolution degradation and artifacts (such as ring and band) especially with high rotation speed. Performing many ultra-fast scans at the TOMCAT beamline with different acquisition rate, we demonstrate how the acquisition time effects on the projection data and reconstructed images. Based on the acquired dataset and exploited realistic model for afterglow, we propose a correction method to remove afterglow from the projections which improves the reconstruction visually and quantitatively.