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

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 8mm (volume similar to 300mm(3), weight similar to 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.