Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Ultrafast electron beam X-ray computed tomography has seen considerable progress in the last few years. Beginning with a limited-angle approach, single-plane, dual-plane and multi-plane tomography arrangements have been studied. Based on these proofs of principle, a single-plane full-angle tomography system has been built up and was used to image and analyze various two-phase flow scenarios. Lately, the dual-plane tomography has also been realized as a full-angle setup, which is now able to measure phase distributions as well as velocity profiles within the object of interest.
Now, we present a full-angle volumetric X-ray computed tomography setup, which comprises eight circular X-ray source paths distributed on a vertically expanded target and one ring of 320 detector elements surrounding the target. The resulting reverse cone-beam geometry allows three-dimensional reconstruction of the imaged object volume using Feldkamp-type reconstruction algorithms. The electron beam is guided consecutively along all circular source paths, which takes 500 µs per path, while the detector elements simultaneously measure the X-ray projections with 1 MHz sampling rate. This results in 500 discrete source positions per revolution and a volume rate of 250 s-1.
The performance of the setup has been demonstrated in phantom as well as two-phase flow experiments, which revealed detailed structures and flow dynamics in 3-D.