Date of Award

2014

Degree Type

Thesis

Department

Electrical and Computer Engineering

First Advisor

Simon, Daniel

Subject Headings

Extreme environments, Planets -- Atmospheres, Spectrum analysis, Venus (Planet) -- Atmosphere, Venus (Planet), Venus, laboratory spectroscopy, infrared absorption, extreme environments

Abstract

NASA Glenn Research Center has designed and built a test chamber that can recreate the hot, dense atmospheric conditions of the deep Venusian atmosphere, where pressures range as high as 92 atmospheres and temperatures as high as 740 K. The majority of this thesis lies in experimentally measuring and quantifying the infrared absorption of CO2 at Venus-like conditions in this laboratory setting. In particular, we describe the challenges and solutions involved in achieving repeatable laboratory test conditions, as well as the iterative process of modifying/optimizing our experimental test setup, including proposed future improvements. We discuss our measured CO2 absorption spectra, qualitatively, in terms of theoretical models, and quantitatively, through comparisons with other available laboratory data. Specifically, we replicated two tests conducted by European Space Agency (ESA) researchers. The first of these tests looked at the effects of high pressure on the infrared absorption of CO2. For this test, a band integration method was used to compare our results to ESA's, resulting in agreement to 1.08 . The second of these tests involved taking CO2 absorption measurements at conditions found 22 km above Venus's surface, measuring the effects of both high pressure and high temperature on the infrared spectra. Band-integrated areas were also calculated for this test, however, since ESA did not publish their band-integrated results, our comparison was based on individual absorbance peaks. For this test, our measurements differed by approximately -12.0 compared with the literature. This difference was attributed to thermal inhomogeneity in our test setup at elevated temperatures, and modifications to improve thermal homogeneity were proposed. Finally, we describe the relevance of this work, especially with regards to the quantification of trace gasses against the strong CO2 background. Specifically, we present data showing how elevated temperatures and pressures modify the spectrum of CO2, and discuss the

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