Development of a low-energy gamma CT system: Application to two-phase pipe flow visualization

This paper describes the application of a low-energy γ-ray computed tomography (CT) system to two-phase flow measurement. A ²⁴¹A_m (59.5 KeV) γ-ray source is used to penetrate a 82 mm i.d. pipe, an array of 17 detector elements is utilized to measure the projection data, and a rotating mechanism is employed to get 3 to 11 projections with the single source. Because this system offers only 3 to 11 projections, and the detector elements are sparsely arranged, conventional reconstruction algorithms are ineffective, thus improvement based on matrix completion algorithm has been developed to improve the imaging quality. Reconstructed results from measurement data demonstrate the effectiveness of this technique. Dynamic experiment result of a horizontally moving Perspex model are also presented, which clearly show the shape and size of the model.