Effect of temperature and radiation damage on the local atomic structure of metallic plutonium and related compounds

Abstract

This focused review provides an overview and a framework for understanding local structure in metallic plutonium (especially the metastable fcc δ-phase alloyed with Ga) as it relates to self-irradiation damage. Of particular concern is the challenge of understanding self-irradiation damage in plutonium-bearing materials where theoretical challenges of the unique involvement of the 5f electrons in bonding limit the efficacy of molecular dynamics simulations and experimental challenges of working with radioactive material have limited the ability to confirm the results of such simulations and to further push the field forward. The main concentration is on extended X-ray absorption fine-structure measurements of δ-phase Pu, but the scope is broadened to include certain studies on plutonium intermetallics and oxides insofar as they inform the physics of damage and healing processes in elemental Pu. The studies reviewed here provide insight into lattice distortions and their production, damage annealing and defect migration, and the importance of understanding and controlling sample morphology when interpreting such experiments.

Towards Quantitative Inference of Nanoscale Defects in Irradiated Metals and Alloys

“…From this comparison, they report that classical defect production models (NRT-dpa and Kinchin-Pease) are insufficient to capture the effect of different bonding on defect evolution in intermetallics. Further validation of this finding with MD simulations -as demonstrated by Okamoto et al (Okamoto et al, 1991) for N-ion irradiated amorphous Pd 80 Si 20 , and Booth and Olive (Booth and Olive, 2017) for pure Pu -would be insightful, but subject to the availability of accurate interatomic potentials.…”

“…This enables experiments to be directly compared to simulations, as demonstrated by Andrianov et al (Andrianov et al, 2021) in Figure 2C. EXAFS has been used to study the impact of self-irradiation in Pu and its alloys as a function of dose (Booth et al, 2007;Booth et al, 2013;Olive et al, 2016;Booth and Olive, 2017). Booth et al use EXAFS to determine the fraction of a sample that is damaged and compare these measurements to estimates based on point defect production and annealing (Booth et al, 2013).…”

Towards quantitative inference of nanoscale defects in irradiated metals and alloys

“…From this comparison, they report that classical defect production models (NRT-dpa and Kinchin-Pease) are insufficient to capture the effect of different bonding on defect evolution in intermetallics. Further validation of this finding with MD simulations (as demonstrated by Okamoto et al [75] for N-ion irradiated amorphous Pd 80 Si 20 , and Booth et al [74] for pure Pu) would be insightful, but subject to the availability of accurate interatomic potentials.…”

“…2(c). EXAFS has been used to study the impact of self-irradiation in Pu and its alloys as a function of dose [71][72][73][74]. Booth et al use EXAFS to determine the fraction of a sample that is damaged and compare these measurements to estimates based on point defect production and annealing [72].…”