July 2025

Journal

Shielded magnetic small-angle neutron scattering for characterization of radioactive samples

By:
Field, Kevin; Massey, Caleb P; Smith, Kurt; Briggs, Samuel; Zhang, Dalong; Littrell, Kenneth C
Journal Name:
Journal of Applied Crystallography
Page Number:
1000-1014
Volume:
58
Issue Number:
3
Publication Date:
July 9, 2025
View DOI Listing:
https://doi.org/10.1107/S1600576725003176

Abstract

The development of a Pb-shielded fixture for the execution of a small-angle neutron scattering (SANS)-based workflow for interrogation of highly irradiated nuclear materials has been explored. The Pb shielding was specially designed to reduce the detected radioactivity from the specimen during SANS experiments, and the overall configuration is termed shielded magnetic SANS (SM-SANS). Two FeCrAl-based alloys, C35M and 125YF, were examined with the SM-SANS technique using a free-form size distribution locally monodisperse model in both the as-received and irradiated states. Quantitative values derived from the free-form size distribution were compared with atom probe tomography experiments. Microstructural and compositional parameters determined using the two characterization techniques were complements of each other. The results demonstrate that the SM-SANS technique is an effective means of characterizing nanoscale clustering in irradiated material systems and provides new avenues for investigating radioactive material microstructures.