No abstract

X-ray computed tomography (CT) systems can produce high resolution images, in which small (sub-millimeter) features can be detected. This requires the X-rays to sufficiently penetrate the object and interact strongly enough to produce measurable attenuation. Low atomic number (low Z), low density objects shielded by high atomic number (high Z) materials result in X-ray reconstructions that lack sufficient contrast to differentiate interior features from noise and reconstruction artifacts. Fast neutron CT offers complementary information to X-rays with superior penetration through high Z shielding and with less severe beam hardening artifacts. However, spatial resolution in X-ray imaging systems is generally superior to that of fast neutron imagers. Here, we quantitatively compare these two complementary modalities to demonstrate the ability to observe small feature locations within two multi-material objects. Quantitative measures include calculation of image gradient at material edges, contrast-to-noise ratio, and F1 score.

No abstract

Neutron radiography and computed tomography may be used to investigate internal structures of complex multi-material objects nondestructively. Thermal neutrons are more effective at producing high-contrast radiographs of objects composed of elements with relatively low atomic numbers (Z). A capability to produce high-quality CT reconstructions from both thermal and fast neutron computed tomography (nCT) using a lens-coupled imaging was demonstrated using various Additively Manufactured (AM'd) and Electrical Discharge Machining (EDM) phantoms, with layers and distinct features, made with intentional voids and out of high-and low-Z elements.