Tracking of oxide formation in laser-produced uranium plasmas.

We use a spatially and temporally resolved emission tracking technique based on optical emission spectroscopy to map the evolution of emission features from uranium and its compounds in a plasma produced by a nanosecond laser. We observe quenching of the emission from neutral uranium (591.538 nm) and uranium monoxide (593.55 nm) species with increasing oxygen concentration and discuss possible reaction pathways for dissociation or formation of higher uranium oxides (UxOy). We further identify spectral features between 320 nm and 380 nm and between 520 nm and 640 nm, which we attribute to UxOy.