DescriptionThe method of industrial x-ray computed tomography (CT) is used for non-destructive testing since years. A new and challenging field of application for CT is dimensional metrology. The achievable quality of measurement results especially with cone beam CT depends on the measurement conditions and the used parameters. Parameters like x-ray tube voltage, current, detectors integration time and number of projections are optimised with the experience of the system operator until now. A simulation software for industrial cone beam CT could do this optimization proc-ess automatically and thus make measurement results user independent. Monte-Carlo simulations are able to represent the interactions of x-rays very accurately, but due to their enormous computational costs it is not suitable for the required optimisation of a full CT scan. It is only applicable as a reference method for simple specimen ge-ometries. Therefore the aim of this work is a time optimized simulation, which mod-els all essential interactions with a sufficient accuracy. The simulation contains the following models: • Polychromatic x-ray tube with a directional target • Interactions of the x-rays with pre- and post-filter (absorption) • Interactions of the x-rays with a virtual specimen, defined by a surface model and a material specification (absorption and scatter) • Interactions of the x-rays within the detector (absorption and scatter) • Manipulator: geometry, etc. Current results and physical models of the simulation tool will be the main issues to be published. More precisely the impact of effects during the image acquisition on to the reconstructed data will be discussed on some selected examples. Covered effects will be geometric blur caused by a drifting focal spot of an x-ray tube, scatter within the object and also scatter within the detector.
|Period||22 Oct 2008|
|Event title||IEEE Workshop on X-Ray Micro Imaging of Materials, Devices, and Organisms: null|