Abstract
Off-focal x rays are an undesirable feature in industrial and medical x-ray computed-tomography scanners that contributes the effects of a large defocused source. They lead to artefacts in tomographic volumes that degrade contrast and resolution. A simple model of an x-ray tube with a transmission target has been developed in Topas, a Monte Carlo (MC) simulation extension to Geant4, to improve the understanding of the origin of off-focal x rays. From the analysis of the MC simulations we are able to identify the origin of various types of off-focal x rays and characterise their spatial distribution and energy spectra. We can then propose and test different mitigation methods, based both on hardware additions as well as improvements in the image reconstruction or data postprocessing.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call