Sub-micrometer resolution neutron tomography

TL;DR

This paper introduces a neutron tomography method achieving sub-micrometer resolution by measuring diffraction spectra and applying phase retrieval, enabling detailed imaging of silicon gratings with significantly improved resolution over existing neutron techniques.

Contribution

The authors demonstrate a novel neutron tomography approach with 300 nm resolution, surpassing previous methods, using diffraction spectra and phase retrieval algorithms.

Findings

Achieved 300 nm spatial resolution in neutron tomography.

Successfully imaged silicon phase-gratings without position-sensitive detectors.

Reconstructed features correspond with electron micrographs.

Abstract

We demonstrate a neutron tomography technique with sub-micrometer spatial resolution. Our method consists of measuring neutron diffraction spectra using a double crystal diffractometer as a function of sample rotation and then using a phase retrieval algorithm followed by tomographic reconstruction to generate a density map of the sample. In this first demonstration, silicon phase-gratings are used as samples, the periodic structure of which allows the shape of the gratings to be imaged without the need of position sensitive detectors. Topological features found in the reconstructions also appear in scanning electron micrographs. The reconstructions have a resolution of about 300 nm, which is over an order of magnitude smaller than the resolution of radiographic, phase contrast, differential phase contrast, and dark field neutron tomography methods. Further optimization of the underlying phase recovery and tomographic reconstruction algorithm is also considered.