PNNL

Abstract

Uranium, because of its pyrophoricity, oxidizes rapidly in an oxygen-containing high-temperature environment. However, so far, the identification of UO emission from a laser-produced plasma system is limited to a spectral feature around 593.55 nm. The aim of this study is to elucidate UO emission features in the visible spectral regime from uranium plasmas generated in an oxygen-containing ambient environment. The plasmas are produced by focusing nanosecond laser pulses on a uranium metal target in a controlled ambient environment. Space- and time-resolved optical emission spectroscopic investigations are used for isolating U molecular emission structures from crowded U atomic line emission. Our studies highlight that the emission from a U plasma even in the presence of trace oxygen is accompanied by a strong background-like emission with partially resolved bands from uranium monoxide and higher oxides. We also report several UO spectral emission bands in the visible spectral region.