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3D isotope density measurements by energy-resolved neutron imaging
1Los Alamos National Laboratory, Los Alamos, NM, 87545, USA. adrian.losko@frm2.tum.de.
Scientific Reports
|April 23, 2022
Summary
This study introduces a new 3D elemental characterization method using neutron imaging for large volumes. The technique accurately maps isotope densities in nuclear fuel, advancing materials analysis.
Area of Science:
- Nuclear Physics
- Materials Science
- Analytical Chemistry
Background:
- Existing 3D elemental characterization tools are limited to atomic to micrometer scales.
- Quantitative elemental analysis in larger volumes (mm-cm) was previously restricted to surface measurements.
Purpose of the Study:
- To demonstrate a novel quantitative 3D elemental characterization method for larger volumes.
- To utilize energy-resolved neutron imaging and known neutron absorption cross sections for elemental mapping.
Main Methods:
- Employed energy-resolved neutron imaging with a pixilated time-of-flight neutron transmission detector.
- Conducted 3.25 million neutron transmission analyses on a 0.25 cm³ sample.
- Utilized tomographic reconstruction to derive 3D isotopic densities.
Main Results:
- Successfully derived 3D isotopic densities for five isotopes.
- Generated elemental maps comparable to X-ray microprobe maps for any cross-section.
- Measured the bulk isotopic density of a U-Pu-Zr-Np-Am nuclear transmutation fuel sample.
Conclusions:
- The novel neutron imaging method provides quantitative 3D elemental characterization for volumes up to centimeters.
- The measured isotopic densities agree well with mass spectrometry, validating the method's accuracy.
- This technique offers a significant advancement for analyzing bulk materials in nuclear and other fields.
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