<p> Presented in this thesis is the construction of an apparatus to produce optically trapped ⁶Li atoms in the two lowest hyperfine states, the observation of cooling the trapped atoms by parametric excitation, and a study on the searching for itinerant ferromagnetism in a two-dimensional Fermi gas.</p> <p> </p> <p> In the parametric cooling experiment, a technique is developed to cool a cold atomic Fermi gas by parametrically driving atomic motions in a crossed-beam optical dipole trap. This method employs the anharmonicity of the optical dipole trap, in which the hotter atoms at the edge of the trap feel the anharmonic components of the trapping potential, while the colder atoms in the center of the trap feel the harmonic one. By modulating the trap depth with frequencies that are resonant with the anharmonic components, hotter atoms are selectively excited out of the trap while keeping the</p> <p> colder atoms in the trap, generating a cooling effect.</p> <p> </p> <p> An analytical study of itinerant ferromagnetism in a two-dimensional atomic Fermi gas is presented, based on the past experiments done with three-dimensional Fermi gases. Here, the formation of repulsive polarons in a strongly-interacting Fermi gas is used as an initial condition.Then the observation of itinerant ferromagnetism is realized by detection of ferromagnetic domains in the two-dimensional gas.</p> <p> </p> <p> Additionally, an experiment and simulation is performed on the effect of velocity-changing collisions on the absolute absorption of ⁶Li vapor in an Ar buffer gas. The dependence of probe beam absorption is observed by variation of beam intensity and spatial evolution. The simulation of an effective three-level energy model with velocity-changing collisions determines a collision rate that agrees with transmission data collected.</p>

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Targets of CO₂ in a differentially-pumped chamber at a pressure of 40 mTorr were bombarded by particles of H₃⁺ at energy of 1 MeV. The optical spectrum created in the collisions was analyzed with a 1-meter, air Czerny-Turner spectrometer. The spectrum excited in the collisions is dominated by molecular bands in the wavelength range from 300 nm to 900 nm. However, one also sees weak atomic lines from C I, C II, O I and O II. The excitation process gives rise to relatively weak atomic spectra in the visible region compared to similar studies of O₂. This paper reports on the carbon dioxide spectra and compares the relative intensities and the line widths of various features with similar studies of oxygen.

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Source: Dissertation Abstracts International, Volume: 35-12, Section: B, page: 6024. / Thesis (Ph.D.)--The Florida State University, 1974.

Source: Dissertation Abstracts International, Volume: 35-02, Section: B, page: 0973. / Thesis (Ph.D.)--The Florida State University, 1973.

Source: Dissertation Abstracts International, Volume: 36-08, Section: B, page: 4031. / Thesis (Ph.D.)--The Florida State University, 1975.

Source: Dissertation Abstracts International, Volume: 33-02, Section: B, page: 0849. / Thesis (Ph.D.)--The Florida State University, 1972.

Source: Dissertation Abstracts International, Volume: 31-05, Section: B, page: 2886. / Thesis (Ph.D.)--The Florida State University, 1970.