Investigation of fragment reconstruction accuracy with in situ few-view flash x-ray high-speed computed tomography (HSCT)

Abstract

Few-view in situ flash x-ray high-speed computed tomography (HSCT) is a computed tomography (CT) technique used to investigate high-speed phenomena on the timescale of microseconds. The successful application to quantitatively analyze and characterize fragments formed during a 1000 m s−1 impact process onto a ceramic plate with a CT reconstruction from only six x-ray projections has been shown. The method delivers spatially resolved 3D information about the fragments at one point in time. This information is not (or only partially) accessible by alternative experimental methods. Therefore, quantifying the accuracy of the measured data is not directly possible. In order to estimate the precision of the method and the influence of different sources limiting accuracy, a simulation study consisting of 250 virtual experiments was carried out. The border conditions of the study are based on the actual experimental data from the six-view experiment. The results show that steel fragments with a diameter of about 8 mm (volume ~ 300 mm3, weight ~ 2.5 g) can be reconstructed with an averaged relative volume deviation of about 30%. For larger framents, the error reduces down to 10% relative average deviation. The spatial position of the center of mass can be determined with an averaged uncertainty of about 0.8 to 1.2 mm for most fragment sizes.

A Priori Information Based Time-Resolved 3D Analysis of the Trajectory and Spatial Orientation of Fast-Moving Objects Using High-Speed Flash X-ray Imaging

“…With certain limitations, this approach is also applicable for fast dynamic processes. A method for high-speed tomography is shown in References [10][11][12], using only six X-ray projections, resulting in a three-dimensional model at one certain point in time. A similar and additionally time-resolved approach based on theoretical simulations is described in Reference [13]; however, this method has not been tested experimentally within this paper.…”

Ultra-Sparse View Reconstruction for Flash X-Ray Imaging using Consensus Equilibrium

“…High speed volume visualization of dynamic processes is an emerging application of computed tomography (CT). In particular, Flash X-ray has been used to study explosive and ballistic events [1,2], material deformation [3], and production line quality control [4], where space and time constraints necessitate sparse view sampling. Even in the absence of such constraints, sparse view CT presents benefits in the form of reduced computation and memory requirements, as well as lower radiation exposure in medical CT.…”

“…In other recent work, Moser et. al [3,2] used the algebraic reconstruction technique (ART) to reconstruct 3D volumes from as few as 6 views. However, ART does not allow for the explicit modeling of prior distributions or even the sensor forward model.…”