A pressurized hydrogen plasma jet is developed for pressure broadening experiments at pressures of from 4 to -20 atmospheres. Operation at low flow rates produced a plasma which was homogeneous in cross section with respect to electron density and temperature, with axial gradients, well suited for broadening experiments. The broadening of two Sil lines, X3905 Å and A2881 Å was studied. Widths and shifts due to broadening by electrons (Stark effect) and also by neutral hydrogen atoms were measured. The experimental results were compared with the theory of Griem in the case of the Stark broadening and with the Unsold theory of Van der Waals broadening for the case of the hydrogen perturbers. Comparison is also made between the experimental results and other experimental results for broadening by argon atoms. Significant disagreement was found, especially in the case of the broadening by hydrogen atoms. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A model - of which a similar type was found applicable to an argon plasma jet - is developed and applied to a laminar helium jet operated at atmospheric pressure with a current of 185 amps. The results are used to investigate the equilibrium properties of the plasma. It was found that the helium plasma was not in a state of Local Thermodynamic Equilibrium but that the neutral atoms were considerably colder than the electrons. (Te ≈ 17,000°K; To≈5,700°K) Instructions are given in the thesis on the construction, operation and properties of a d.c. plasma jet. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 165-170).

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 42-43)