Self-irradiation damage to the local structure of plutonium and plutonium intermetallics

The effect of self-irradiation damage on the local structure of delta-Pu, PuAl2, PuGa3, and other Pu intermetallics has been determined for samples stored at room temperature using the extended x-ray absorption fine-structure (EXAFS) technique. These measurements indicate that the intermetallic samples damage at a similar rate as indicated in previous studies of PuCoGa5. In contrast, delta-Pu data indicate a much slower damage accumulation rate. To explore the effect of storage temperature and possible room temperature annealing effects, we also collected EXAFS data on a delta-Pu sample that was held at less than 32 K for a two month period. This sample damaged much more quickly. In addition, the measurable damage was annealed out at above only 135 K. Data from samples of delta-Pu with different Ga concentrations and results on all samples collected from different absorption edges are also reported. These results are discussed in terms of the vibrational properties of the materials and the role of Ga in delta-Pu as a network former. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794016]