Gas-Phase Molecular Formation in Actinide Laser-Produced Plasmas

Uranium and plutonium oxidize very rapidly in an oxygen-rich environment like air. Understanding the gas-phase actinide oxide molecular formation through plasma- and thermochemistry is very important for numerous fields including forensic analysis, environmental monitoring, debris analysis in a weapons detonation event, or reactor accident scenario, and actinide nucleation physics. There have been significant recent efforts to understand the chemical progression from U atoms to diatoms (UO) and polyatomic molecules (U
x
O
y
).
^1–3
However, emission analysis of high-temperature gas-phase oxidation of U and Pu and the corresponding plasma chemistry are very complex considering their very congested spectral features. In addition to these, the spectra may contain isotopic shifts and hyperfine structures if the sample is enriched.