Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves i-iii).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 338-345).

Thesis (M.S.)--University of Wisconsin--Madison, 1980. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 557-562).

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 350-368).

Orientador: Gilberto M. Gualberto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-21T21:13:10Z (GMT). No. of bitstreams: 1 Pedreira_VandadoAmaralV_M.pdf: 844584 bytes, checksum: 2a2b2be7ecb54390cbe9dab4102cf709 (MD5) Previous issue date: 1996 / Resumo: Os cristais iônicos KBr e KI não apresentam atividade Raman. Espectros Raman destes cristais, após imersão em bromo líquido, exibiram linhas com freqüências identificadas como sendo devida aos compostos KBr3 e IBr, ao Br2 e às formas alotrópicas 79Br -79Br. 79Br -81Br e 81Br -81Br e aos íons Br3- e Br5-. -Espectros Raman do grafite pirolítico altamente orientado (HOPG) intercalados com Br2 foram estudados. O estágio encontrado foi n=2, evidenciado pelo pico intenso em w = 244 cm-1 e pelos seus harmônicos 2w0 ,3w0 ,4w0 ... . Estruturas menores foram observadas na região espectral dominada pelo bromo sólido / Abstract: The ionics crystals KBr and KI do not present Raman activity. Raman spectra of these crystals after immersing in liquid bromine exhibits lines with frequencies identified as been due to the compounds KBr3 and IBr, to the alotrophics forms 79Br - 79Br, 79Br- 81Br and 81Br - 81Br and to the ions Br3- and Br5-. -Raman spectra of highly oriented pyrolitic graphite (HOPG) intercalated with Br2 were also investigated. The stage number found was n=2, evidenced by the intense peak in w0 = 244 cm-1 and by its harmonics 2w0, 3w0, ... . Minor structures were also observed in the spectral region dominated by the solid bromine / Mestrado / Física / Mestre em Física

University of Macau / Faculty of Science and Technology / Department of Computer and Information Science

[No abstract submitted] / Science, Faculty of / Physics and Astronomy, Department of / Graduate

[No abstract submitted] / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Stimulated Raman scattering (SRS) has been studied experimentally in a CO₂ laser plasma interaction. A N₂ gas jet target was irradiated with CO₂ laser light (wavelength, ⋋ = 10.6 µm and frequency, ѡ₀) at intensities up to 10¹⁴ Wcm⁻². SRS occurs at intensities greater than 3 x 10¹³ Wcm⁻², which is fair agreement with threshold predictions for a plasma with an electron temperature of 300eV and a density scale length of 300µm. After this intensity is reached, the plasma waves grow exponentially in time with a growth rate of 6 x 10⁻³ѡ₀. This was measured with ps resolution ruby laser Thomson scattering. Spatial growth was also observed. Scattered infrared light at 2⋋ was found. Weak IR light in a broad band near 15µm was also found. The saturated plasma wave level and the number of hot electrons at 150 keV are well correlated, which indicates that trapping is responsible for the electrons. However, trapping is not responsible for the saturation of the instability. Frequency resolved Thomson scattering revealed that ion acoustic waves start at the peak of the SRS fluctuations. Once the ion acoustic waves grow to a large amplitude, SRS is quenched and does not reappear. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Tunable high order anti-Stokes radiation produced by stimulated Raman scattering in liquid nitrogen is studied experimentally. The light beams of two lasers of different frequencies a ruby laser and tunable dye laser --.are simultaneously focussed in liquid nitrogen and two distinct series of anti-Stokes lines are observed. The dye laser anti-Stokes lines can be changed in frequency by tuning the dye laser. The intensities of the two series of lines are investigated as a function of both ruby and dye laser power, The dye laser anti-Stokes line intensities are found to have a distinct threshold for ruby laser power but no threshold for dye laser power. The experimental results support a two step model in which the ruby laser acts as a pump for molecular vibrations which in turn modulate the dye laser frequency. / Science, Faculty of / Physics and Astronomy, Department of / Graduate