Tomography of transient events

A noninvasive technique for the determination of density distributions of slices of rapidly moving objects is described. The method, an extension of the computerized tomography approach known from medical applications, is based on the simultaneous recording of transmission profiles of 21 1-MV flash X-ray sources and the reconstruction of the image using the maximum-entropy reconstruction algorithm. Spatial resolution on a 200-mm object is of the order of 2-4 mm, and density-difference determination much better than in conventional radiographs is possible. The paper focuses on the choice of the system components, the design philosophy, and the layout of the facility. Discussion of unwanted side effects, such as scattering and artifact elimination is included, and the wide applicability of the technique is shown by actual reconstructed images of known geometry and disposition.