Plume hydrodynamics and plasma-gas intermixing drives chemical reactions in laser ablation plasmas, where molecular formation is shown to occur during early times (<100 ns) in the presence of strong laser-induced shockwaves.

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Shadowgraphic measurements are combined with theory on gas-dynamics to investigate the shock physics associated with nanosecond laser ablation of cerium metal targets. Time-resolved shadowgraphic imaging is performed to measure the propagation and attenuation of the laser-induced shockwave through air and argon atmospheres at various background pressures, where stronger shockwaves characterized by higher propagation velocities are observed for higher ablation laser irradiances and lower pressures. The Rankine-Hugoniot relations are also employed to estimate the pressure, temperature, density, and flow velocity of the shock-heated gas located immediately behind the shock front, predicting larger pressure ratios and higher temperatures for stronger laser-induced shockwaves.

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Rapid, in-field, and standoff analysis of radiological materials is extremely important to nuclear applications and is possible with laser ablation spectroscopy techniques; however, applying optical spectroscopy to the measurement of radiological materials presents numerous challenges.