Plutonium (Pu) is well known to have complex and unique physico-chemical properties . Notably, the pure metal exhibits six solid-state phase transformations with large volume expansions and contractions along the way to the liquid state: α → β → γ → δ → δ' → ε→ liquid. Unalloyed Pu melts at a relatively low temperature ∼640 °C to yield a higher density liquid than that of the solid from which it melts, (Figure 1). Detailed understanding of the properties of plutonium and plutonium-based alloys is critical for the safe handling, utilization, and long-term storage of these important, but highly toxic materials. However, both technical and and safety issues have made experimental observations extremely difficult.