  Flash X-ray computed tomography (CT) is an important imaging modality for
characterization of high-speed dynamic events, such as Kolsky bar impact
experiments for the study of mechanical properties of materials subjected to
impulsive forces. Due to experimental constraints, the number of X-ray views
that can be obtained is typically very sparse in both space and time, requiring
strong priors in order to enable a CT reconstruction. In this paper, we propose
an effective method for exploiting the cylindrical symmetry inherent in the
experiment via a variant of total variation (TV) regularization that operates
in cylindrical coordinates, and demonstrate that it outperforms competing
approaches.
