On a Method For Reconstructing Computed Tomography Datasets from an Unstable Source

Abstract

As work continues in neutron computed tomography, at Los Alamos Neutron Science Center (LANSCE) and other locations, source reliability over the long imaging times is an issue of increasing importance. Moreover, given the time commitment involved in a single neutron image, it is impractical to simply discard a scan and restart in the event of beam instability. In order to mitigate the cost and time associated with these options, strategies are presented in the current work to produce a successful reconstruction of computed tomography data from an unstable source. The present work uses a high energy neutron tomography dataset from a simulated munition collected at LANSCE to demonstrate the method, which is general enough to be of use in conjunction with unstable X-ray computed tomography sources as well.

Artifacts and quantitative biases in neutron tomography introduced by systematic and random errors

“…However, care needs to be taken to not introduce other effects, such as a reduction of SNR or streaking. Therefore, correction of projections using the common method of using open beam ROIs or those documented in [15] are nonetheless recommended where possible, to minimize the bias from build-up effects, scintillator degradation, other efficiency drifts, SNR variations or streak artifacts during a tomography scan.…”

“…In addition, sample LAC standards are often used for benchmarking different facilities and their performance [14]. Recently, the consequences and mitigation methods for reconstructions involving unstable sources have been investigated [15]. However, limited research on the topic means the effect of neutron flux variations on quantitative analysis and specifically on the neutron LACs remains unclear.…”