Degree Type

Dissertation

Date of Award

1986

Degree Name

Doctor of Philosophy

Department

Chemistry

Abstract

Atomic spectroscopic methods have been widely accepted for the analyses of many element. Optimizations of the analytical signals require thorough fundamental understanding of each elemental step involved in a particular measurement. Important parameters such as spatially resolved temperature and concentration profiles of the atomizers are necessary for researchers to study the efficiency of free atom production, the dissociation and excitation processes, and the effects of interferences;A new concept for the determination of spatially resolved vibrational temperatures is demonstrated. A collimated laser beam is coupled to a vidicon camera to allow spatial mapping of absorption in flames. Vibrational temperature for each spatial location of the flame can be calculated by measuring the relative intensities of absorption from different vibrational levels in the ground states of the molecules. Temperature information generated by this system is very helpful to the understanding of dissociation and recombination of molecules in flames;The laser microprobe is a powerful technique for in situ elemental analysis of a small spot on the surfaces of any materials. Optimizations of the laser microprobe require the understanding of the fundamental processes that occur in the formation of the laser-generated plume. The availability of dynamic information such as spatial and temporal distribution of atoms and molecules is very important for the study of vaporization mechanisms. The spatial distribution of sodium dimers in a laser-generated plume is obtained for the first time in our laboratory;Finally, a new imaging instrument based on an acousto-optic deflector is developed for diagnostic studies of pulsed atom sources. This device has the capability of deflecting a laser beam across a spatial region of interest in the microsecond regime so that transient events can be recorded in real-time. This capability is demonstrated by applying this system to acquire spatially resolved scattering profiles of particles and absorption profiles of atoms in a;laser microprobe. This information gives insight into the efficiency of free atom production and the formation and decay of a single laser-generated plume; *DOE Report IS-T-1191. This work was performed under Contract W-7405-eng-82 with the U.S. Department of Energy.

DOI

https://doi.org/10.31274/rtd-180813-12791

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Carmen Wah-kit Huie

Language

en

Proquest ID

AAI8615057

File Format

application/pdf

File Size

149 pages

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