Graduate Thesis Or Dissertation
 

Nonlinear Raman spectroscopy of gases

Pubblico Deposited

Contenuto scaricabile

Scarica il pdf
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k643b449t

Descriptions

Attribute NameValues
Creator
Abstract
  • Applications of several methods of coherent nonlinear Raman Spectroscopy have been made in this thesis research. The theory and potential of one of these, Photoacoustic Raman Spectroscopy (PARS), is discussed in chapter two. Experimental results are presented which illustrate the sensitivity of this method and establish sampling conditions for maximum acoustic signals. As part of this work a new photoacoustic Raman cell was designed which is simple to use and gives improved detection capability. Measurements of the nonresonant third order susceptibility of various gases are presented in chapter three. This quantity has been very difficult to determine in absolute terms and is needed to properly account for CARS lineshape distortions which affects frequency and intensity measurements for resonant transitions. Values were measured by first determining nonresonant susceptibilities relative to N₂. Recent linewidth and Raman cross section data were then used to calculate an absolute resonant susceptibility for H₂. Finally, by a separate measurement of the N₂ /H₂ susceptibility ratio, accurate absolute values for the nonresonant third order susceptibility of a number of common gases were deduced. Chapter four describes a study of the rotational relaxation of para hydrogen (and various mixtures) in a supersonic free jet expansion. CARS measurements were used to determine the H₂ rotational temperature in the free jet. One goal of this work was to test several H₂ --- H₂ theoretical interaction potentials. This was done by combining models for the expansion properties of the jet and for relaxation of hydrogen with theoretical values for the cross sections. Rotational temperature profiles of the jet were calculated and the theoretical predictions of several potentials are in good accord with the actual experimental results. Using the complete fluid mechanical model for the expansion process, one can develop a light preference can be developed for the M79 potential of Schaefer and coworkers. Similar calculations were preformed for H₂ --- He mixtures.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Dichiarazione dei diritti
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Le relazioni

Parents:

This work has no parents.

In Collection:

Elementi

Thumbnail Titolo Data caricata Visibilità Azioni
file details LundeenThomasF1984.pdf 2017-08-16 Pubblico Scaricare