Neutron Dark-Field Imaging with Edge Illumination

TL;DR

This paper introduces a simple neutron dark-field imaging technique using edge illumination with laser-ablated metal foils, enabling detailed micro-structure analysis in materials with high contrast and robustness.

Contribution

The work presents a novel, easy-to-implement neutron dark-field imaging setup that does not require complex coherence conditions, expanding potential applications in material micro-structure investigation.

Findings

Achieved over 80% visibility in intensity modulation

Demonstrated the method with two test samples showing complementary contrast

Proposed a robust approach suitable for neutron radiography and tomography

Abstract

We report on an Edge Illumination setup enabling neutron dark-field imaging where two amplitude modulators are used to structure and subsequently analyze the neutron beam. The modulator and analyzer are manufactured by laser ablation of readily available thin metal foils. The sample representation in terms of transmission and dark-field contrast is extracted by numerically inverting a convolution model for the intensity modulation function which had a visibility exceeding 80\%. Two test samples are presented to show how dark-field contrast can complement the more conventional neutron radiography, in particular to investigate the micro-structure of materials. Thanks to the simplicity of the setup, the negligible coherence requirements and the robustness of the method, this approach may find application in multi-contrast neutron radiography and tomography.