Fused x-ray and fast neutron CT reconstruction for imaging large and dense objects

• Published in: Journal of applied physics 2022-10, Vol.132 (15)
• Main Authors: Champley, Kyle M., Hardy, Anthony J., Cherepy, Nerine, Townsend, Andrew, Hall, James, Harke, Kathryn J., Carter, Clint, Bendahan, Joseph, Tringe, Joseph W.
• Format: Article
• Language: English
• Subjects: Algorithms; Applied physics; Atomic properties; Bremsstrahlung; Computed tomography; Data acquisition; Fast neutrons; Neutrons; Reconstruction; X-rays
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0098960

Megavolt x-ray computed tomography (CT) is a powerful tool for three-dimensional characterization. However, its utility is limited for large objects composed of high-atomic number (Z) materials, where x rays fail to penetrate. Information from fast neutron CT (FNCT) can complement x-ray CT reconstructions since fast neutrons can more readily penetrate high-Z objects. Here, we demonstrate a method for combining FNCT and x-ray CT data to create a single reconstruction, more accurate than could be achieved with either x rays or fast neutrons alone. The algorithm was tested on an exemplar comprising multiple concentric, nested cylinders of different materials. Simulated and empirical x-ray CT data were acquired for the exemplar using a 9 MV bremsstrahlung spectrum. Additional simulated and empirical FNCT data were acquired using an accelerator based fast neutron source. The FNCT data were used to synthesize x-ray CT data and augment the x-ray CT data missing due to lack of penetration. This approach mitigates artifacts that would otherwise negatively affect the accuracy and resolution of a single-modality reconstructed volume.