Comparison of Thermal Neutron and Hard X-ray Dark-Field Tomography

Abstract

High visibility (0.56) neutron-based multi-modal imaging with a Talbot–Lau interferometer at a wavelength of 1.6 Å is reported. A tomography scan of a strongly absorbing quartz geode sample was performed with both the neutron and an X-ray grating interferometer (70 kVp) for a quantitative comparison. Small scattering structures embedded in the absorbing silica matrix were well resolved in neutron dark-field CT slices with a spatial resolution of about 300 μm. Beneficial effects, such as monochromaticity and stronger penetration power of the used neutron radiation, helped to avoid the beam hardening-related artificial dark-field signal which was present in the X-ray data. Both dark-field modalities show mostly the same structures; however, some scattering features appear only in the neutron domain. Potential applications of combined X-ray and neutron multi-modal CT enabling one to probe both the nuclear and the electron density-related structural properties are discussed. strongly absorbing samples are now accessible for the dark-field modality by the use of thermal neutrons.

Material Discrimination Using X-Ray and Neutron

“…For this reason, accurate identification of hazardous materials that pose a threat to safety is essential and required in the field of security screening. Neutrons can help to distinguish objects with low atomic numbers, which is a limitation of X-rays, and many related studies have been conducted since the September 11, 2001 attack [10][11][12]. X-rays and neutrons show different characteristics in their interactions with matter, and this difference enables the discrimination of matter [13].…”