Date of Award
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Laser-induced plasmas are easy to produce high-temperature sources (~50,000 K) of highly-excited atoms and ions for use in atomic spectroscopy experiments. Emission from the plasma, when dispersed in a high-resolution échelle spectrometer, can be used to measure the relative intensity of all emission lines from hundreds of thermally-populated energy levels. Our recent work has focused on measuring the relative intensities of emission lines from neutral, singly-ionized, and doubly-ionized species of rare-earth metals due to their significant importance to astronomers and astrophysicists for their overabundances in "chemically peculiar" and galactic halo stars. Experimental parameters have been extensively studied to characterize plasma emission for these species at various observation times after the laser pulse, at various background pressures, various laser pulse energies, and various target compositions. Recent work has consisted of incorporating an optical parametric oscillator to resonantly excite specific energy levels within the plasma, increasing emission line intensity and eliminating line blending.
Putnam, Russell, "Recent Advances in the Measurement of Rare-Earth Metal Transition Probabilities Using Laser-Induced Plasmas" (2014). Electronic Theses and Dissertations. 5275.