Laser‐induced annealing of aged PuO 2

• Published in: Journal of Raman spectroscopy Vol. 52; no. 8; pp. 1486 - 1489
• Main Authors: Villa‐Aleman, Eliel, Dick, Don D., Christian, Jonathan H., Foley, Bryan J.
• Format: Journal Article
• Language: English
• Published: Netherlands Wiley Blackwell (John Wiley & Sons) 01.08.2021
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.6185

Abstract Plutonium dioxide (PuO 2 ) is an important compound used in nuclear fuel, irradiation targets, and heat sources. As such, improved understanding of its structural and spectroscopic properties has numerous applications. Alpha particle‐induced damage of a PuO 2 crystal lattice modifies several properties of its Raman spectrum, including band intensities, positions, and widths. The decay also induces growth of new bands and creates electron‐trapped defects with luminescent properties. Herein, we show for the first time that laser‐induced heating can reverse damage to an aged and damaged PuO 2 lattice. Using automated instrumentation to heat a single 6–10 μm spot to temperatures above 1,300°C, we show that laser‐induced annealing of aged PuO 2 results in restoration of T 2g band intensity with a concomitant decrease in defect band intensity, a result that indicates laser annealing can be used to reverse age‐damage in PuO 2 . This laser annealing approach permitted in situ observation of temperature‐dependent Raman spectral changes, thereby providing insight into the thermodynamics of structural alterations in a radiolytically damaged PuO 2 .