Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.622678
Title: Intensity variations in spectra of atmospheric gases at low temperatures
Author: Linton, Colan
Awarding Body: University of London
Current Institution: Imperial College London
Date of Award: 1966
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Abstract:
This thesis describes experiments in which the intensities of bands of the nitrogen first positive system were measured. The system was excited by a low temperature discharge through both pure nitrogen and mixtures of nitrogen and helium at various pressures and currents. Several arrays of Franck Condon factors have recently been calculated for the system, both analytically and numericalJy. The experimental results were used to assess the reliability of each array and it was found that those calculated numerically were more reliable. The various arrays were used to investigate the effect of different q values on the calculated variation of the elec— tron transition moment. A table of relative band strengths has been presented. The experimental results were also used to estimate the applicability, over a wide range of conditions, of the theory behind the calculation of the band strengths. There were indications that the theory does not hold for all conditions. Possible excitation processes have been examined and intensity distributions predicted theoretically. These, together with the experi— mental distributions, enabled the impotence of the various processes to be assessed. The experi— mental and theoretical distributions were compared with auroral distributions. A series of computer programmes was written to facilitate the systematic processing of the experimental results and several more programmes were written to perform all the necessary theoretical calculations. Some new bands in the oxygen second negative system were observed and measured, and other bands have been reclassified. The variation of intensity of the bands with changing conditions was observed.
Supervisor: Pearse, R.W.B. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.622678  DOI: Not available
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