2026-09-24T08:01:06Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/25043 2023-07-10 col_2142_5131 col_2142_8859 com_2142_5130 com_2142_8858 com_2142_234

Goldstein, L. Freiberg, Robert Jerry 2011-05-27T14:13:05Z 2011-05-27T14:13:05Z 10000-01-01 1966 The study of the interaction between the electron gas and the atoms in excited states has been undertaken for a gas discharge situated in a high gain optical cavity. Of particular interest is the effect of lasering upon this interacti.on. Spatially resolved electron density and electron temperature measurements are presented for a DC excited 3.51 P. (5d 33 -76P22) xenon laser operating in a capillary bore tube over a pressure range of 12.5 to 25.5 m Torr. Anode directed gradi,ents in the electron and neutral gas ,densities are observed and are attributed to electrophoretic effects present in the closed capillary discharge tube. As a result of these gradients, the local population inversion along the axis of the tube varies and, consequently. affects the output of the 3.51 jJ. laser. The influence of lasering upon these low-pressure capillary xenon discharge,s is investigated experimentally by periodically spoiling the Q of the laser cavity by means of a mechanical chopping wheel. It is observed that lasering noticeably alters both the state of the electron gas and the populations of the excited xenon atoms. The cU:t'rent of the DC exci.ted discharge is quenched up to 0.02 per cent during lasering due to laser-induced variations of the electron density and mean energy. Spatially resolved microwave cavity measurements indicate that the electron number density may experience i,ncreases and decreases depending upon local discharge condj.tions. Microwave radiometric measurements reveal that the electron temperature is also affected by lasering. Variations in the microwave cavity Q and in the electron drift velocity due to lasering are in good qualitative agreement with the radiometric data. Confirming spectroscopic observations of laser-induced changes in the spontaneous radiation along the discharge tube are presented. It is demonstrated that excitation of the 6s metastables via electronic impact is instrumental in populating the lower laser level and contributes to a reduction in the local population inversion. Evidence for various radiative and collisional mechanisms responsible for the propagation of the .laser-induced perturbation from the 5d 33 and 6P22 levels to other excited levels is also presented. It is suggested that laser media in general can be analyzed and improved upon by studying the laser-induced changes in the excitation and. relaxation processes. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-27T14:13:05Z No. of bitstreams: 1 1966_freiberg.pdf: 4665849 bytes, checksum: 1f8606ab48ee8dc75af5e9d621e55dfa (MD5) Made available in DSpace on 2011-05-27T14:13:05Z (GMT). No. of bitstreams: 1 1966_freiberg.pdf: 4665849 bytes, checksum: 1f8606ab48ee8dc75af5e9d621e55dfa (MD5) Previous issue date: 1966 Restriction data tranferred 2014-07-01T11:12:25-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-27T14:13:05Z Item is restricted indefinitely. Thesis U of I Only 6176706 http://hdl.handle.net/2142/25043 en 1966 Robert Jerry Freiberg electron gas lasers xenon laser gas density measurements plasma electron and atom interactions Experimental investigation of the interaction between the electron gas and the excited atoms in a plasma by means of a xenon laser Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.