Cavity Ringdown Spectroscopy in Nitrogen/Oxygen Mixtures in the Presence of Alpha Radiation

<p>This research was part of an effort to experimentally validate computational models under development for radiation-induced atmospheric effects. Cavity Ringdown Spectroscopy (CRDS) was used to measure the concentration of chemical products generated as a result of radiation interactions in a controlled atmosphere. Experiments were conducted in a vacuum chamber interfaced with a gas introduction system that controlled the initial atmospheric composition. A quadrupole mass spectrometer and tunable dye laser were integrated to confirm initial atmospheric composition, and provide wavelength flexibility for detecting a variety of chemical products generated by radiation interactions. CRDS measurements were made for ozone production resulting from alpha radiation interactions in nitrogen-oxygen mixtures while the Polonium 210 alpha sources were cycled between being shielded and exposed.</p> <p>The beginning of this thesis will provide brief reviews of ionizing radiation and ozone formation, along with explanations of Cavity Enhanced Absorption Spectroscopy and CRDS. This is followed by a description of the existing vacuum and optical system, as well as the modifications required to integrate the mass spectrometer and dye laser. Another chapter details the modifications made to the existing software, as well as new software developed for the mass spectrometer and dye laser. Finally, results are presented showing the rapid production of ozone following exposure of the alpha radiation to the controlled atmosphere. Results also show ozone concentrations rapidly decreasing when the source was re-shielded, but when the source was re-exposed, the ozone concentration started at the previous concentration and continued to increase. This indicates the presence of a possible ozone catalyst.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Physics and Astronomy

Year dc:date.available

2016

Author dc:creator

• Gautrau, Sidney John

Contributors dc:contributor

• Chris Winstead
• Ras Pandey
• Michael Vera

• ringdown
• ozone
• CEAS
• CRDS
• alpha
• laser
• Atomic, Molecular and Optical Physics
• Optics

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/258

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1286