Synchrotron Radiation as a Probe of Chemical Information Using Novel Experimental Configurations

by Farquar, George

Abstract (Summary)
Determination of chemical information with synchrotron radiation is an area of great scientific interest, and expanding the range of available techniques is the topic of this dissertation. The experimental methods described herein allows for a significant advancement of the availability of subtle chemical information. This dissertation uses ionizing radiation to study three chemical systems. First, the l=3 shape resonance in CO is investigated using a cryogenically cooled gas jet. Shape resonant effects have been studied for many years. Previously, this was accomplished on the vibrational structure of molecules with a limited ability to determine the rotational substructure effects. A dramatic increase in the ability to determine shape resonant effects is shown as a direct result of the reduction in gas temperature. Second, the ability to use X-ray spectroscopic data to determine the composition of mixed metal oxidation states of significant environmental consequence is described. The major advancement is a combination of in-situ data collection with novel data reduction techniques. Results from this study demonstrate that X-ray spectroscopy is a powerful probe of surface reactions relevant to combustion problems. Finally, the separation of ions with the same chemical composition from two different parent ions is necessary to determine the lineage of the molecule. Preliminary results are presented that demonstrate the ability of a novel use of a time of flight velocity map imaging apparatus to focus a zero energy ion event with mass information. In addition a demonstration of the resolution obtainable is shown, along with the ability to determine the components of a mixture of gases in the range of less than 1%. Eventual applications will allow the study of reactive species such as clusters created in gas jets.
Bibliographical Information:

Advisor:Mary Judith Wornat; Britt Thomas; Erwin Poliakoff; Randall Hall; Neil Kestner

School:Louisiana State University in Shreveport

School Location:USA - Louisiana

Source Type:Master's Thesis



Date of Publication:11/12/2003

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