An Investigation of the Singlet Delta Oxygen and Ozone Yields From the Pulsed Radiolysis of Oxygen and Oxygen-Noble Gas Mixtures

The experiments discussed in this thesis were performed with a flowing gas apparatus coupled to the University of Illinois TRIGA reactor. The detectors ((lamda) = 1.27 microns, 634 nanometers) were calibrated with a novel NO(,2) titration scheme and the absorbed dose was estimated from the ozone concentrations measured in pure oxygen. The results of these experiments revealed an O(,2)(a('1)(DELTA)) production efficiency of 0.14% for direct nuclear pumping in an argon-oxygen mixture. Extensive modeling of the oxygen and argon-oxygen mixtures were benchmarked against these and other experiments. However, good agreement over a broad absorbed dose range was only possible if the O(,4)('+) + O(,4)('-) neutralization reaction was assumed to be nondissociative. In a second set of experiments with a nuclear sustained electrical discharge (low E/N), the O(,2)(a('1)(DELTA)) production efficiency was (TURN)0.40% for the electrical power densities examined. In addition, the O(,2)(a('1)(DELTA)) was observed to scale with the square root of the electrical power deposition but was independent of the oxygen concentration. A simple analytic model was developed which explains this behavior as a characteristic of an externally sustained discharge involving an electron attaching gas such as oxygen. The results of these experiments and the modeling of the chemical kinetics will be discussed in this thesis with an emphasis on optimizing the O(,2)(a('1)(DELTA)) and O(,3) yields.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Zediker, Mark Steven

• Chemistry, Nuclear

Identifier

(UMI)AAI8422182

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70898