Abstract

Diffuse reflectance spectroscopy measurements in the shortwave infrared (930–1600 nm) spectral region were acquired for Pu₂(C₂O₄)₃•9H₂O and its thermal decomposition product, PuO₂. We analyzed a total of eight PuO₂ samples that were produced at different calcination temperatures (300, 350, 450, 525, 600, 675, 750, and 900 °C). Our goal was to identify spectroscopic fingerprints that could be used to gain retrospective information regarding the production parameters of these important nuclear compounds. The diffuse reflectance spectrum of Pu₂(C₂O₄)₃•9H₂O features several broad bands that currently preclude detailed analysis. However, all PuO₂ samples produced relatively sharp spectral features that got sharper and more intense for samples that were produced at higher calcination temperatures. The electronic band observed at 1433 nm in the diffuse reflectance spectra of PuO₂ was found to be a sensitive indicator of crystallinity; a result that is corroborated by ancillary Raman spectroscopy measurements. Principal component analysis of diffuse reflectance spectra was able to clearly rank and categorize PuO₂ samples based on the calcination temperature that was employed during their production. Thus, we show herein that important retrospective information pertaining to the process history of PuO₂ can be gained through the relatively simplistic combination of diffuse reflectance spectroscopy and principal component analysis. This discovery presents a new method for determining the provenance and process history of PuO₂ and should have an impact in the fields of nuclear forensics and nuclear nonproliferation.

© 2023 The Author(s)

Comparison of a physical model and principal component analysis for the diagnosis of epithelial neoplasias in vivo using diffuse reflectance spectroscopy

Melissa C. Skala, Gregory M. Palmer, Kristin M. Vrotsos, Annette Gendron-Fitzpatrick, and Nirmala Ramanujam
Opt. Express 15(12) 7863-7875 (2007)

Principal frequency component analysis based on modulate chopper technique used in diffuse reflectance spectroscopy measurement

Shaoxiu Song, Gang Li, Xingwei Hou, Shengzhao Zhang, Yue Yu, and Ling Lin
Appl. Opt. 57(5) 1043-1049 (2018)

Comparison of principal component analysis and biochemical component analysis in Raman spectroscopy for the discrimination of apoptosis and necrosis in K562 leukemia cells

Yi Hong Ong, Mayasari Lim, and Quan Liu
Opt. Express 20(20) 22158-22171 (2012)

Determination and correction of spectral phase from principal component analysis of coherent phonons

Emmanuel B. Amuah, Khalid M. Siddiqui, Maurizio Monti, Allan S. Johnson, and Simon E. Wall
Opt. Express 32(3) 3817-3825 (2024)

Principal component analysis of dynamic fluorescence diffuse optical tomography images

Xin Liu, Daifa Wang, Fei Liu, and Jing Bai
Opt. Express 18(6) 6300-6314 (2010)