A limited-angle CT approach for a fast scanned electron-beam X-ray tomography with application to multi-phase flow measurements


A limited-angle CT approach for a fast scanned electron-beam X-ray tomography with application to multi-phase flow measurements

Speck, M.; Hampel, U.; Koch, D.; Mayer, H.-G.; Menz, H.-J.; Prasser, H.-M.; Schleicher, E.

We devised and tested a computed tomography approach that utilises a scanned electron beam X-ray source to produce multiple projections of an object at scan rates of 1000 frames per second and at an in-plane resolution of 1 mm. The measurement setup consists of an electron beam unit, a cylindrical tungsten target, and a detector line array which are operated inside a vacuum enclosure. By means of fast periodic electron beam deflection we produce a linearly moving focal X-ray spot on the tungsten target. The X-ray detector is read out in synchronisation with the beam deflection signal such that a set of consecutive tomographic projections from an object that is placed between target and detector can be obtained. This approach has some attractive features: it gives the highest achievable axial resolution, which is necessary to image fast moving flow structures and it is comparatively moderate in effort and costs. However, these advantages are compromised by the fact, that the projection data is incomplete with regard to the projection angle. The arising limited-angle problem may be solved by iterative image reconstruction algorithms. We will show, that this approach is suitable for a certain class of flow problems which are characterised by less complex object distributions and a high degree of available a-priori information, such as two-phase flows and particle tracking problems. In the presentation we will give an overview on the method, present first experimental results and discuss the image reconstruction process in some more detail.

Keywords: limited-angle tomography; high-speed tomography; algebraic reconstruction

  • Contribution to proceedings
    Proceedings of the 4th World Congress on Industrial Process Tomography, 05.-08.09.2005, Aizu, Japan
  • Lecture (Conference)
    4th World Congress on Industrial Process Tomography, 05.-08.09.2005, Aizu, Japan

Permalink: https://www.hzdr.de/publications/Publ-6762
Publ.-Id: 6762