Degree Type

Dissertation

Date of Award

1937

Degree Name

Doctor of Philosophy

Department

Physics and Astronomy

Abstract

This thesis was a quantitative study of the variation in intensities of certain lines in the hydrogen spectrum as a function of excitation frequency and pressure when internal electrodes were used. The high frequency voltage was applied to the gas by the connection of a push-pull oscillator to internal carbon electrodes. The gas system was designed to obtain spectroscopically pure hydrogen. The logarithmic sector method was used to measure the intensities of the spectrum lines, and a cathode ray oscillograph was used to measure the potential difference between the electrodes;The spectrograms were taken for pressures ranging from .005 to .3 mm. of mercury and frequencies of oscillation from 0 to 5 · 107 C. P. S;The results of the investigation show: (1) There is a variation in intensity of the spectrum lines for different pressures and frequencies of excitation. (2) The results are very similar when either internal or external electrodes are used. (3) The ratio of the intensities of Hbeta, Halpha, and Hdelta to H alpha increase for low pressures. (4) The ratios of the populations in the higher order states increase with a decrease in pressure. (5) For low pressures the probability of excitation is as great for the higher frequency terms as for the lower ones. (6) Thomson's theory for sparking potentials applies to maintenance potentials. (7) The optimum pressure is such that approximately 12 times the kinetic theory mean free path of the electron is equal to the interelectrode distance. (8) The amplitudes of oscillation of the free electron for wavelengths which give line intensity minima and maxima are multiples of the electronic mean free path. (9) The impurities which are commonly observed in this type of discharge phenomena were eliminated by the design of the tube and the use of liquid air.

DOI

https://doi.org/10.31274/rtd-180813-14226

Publisher

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

Copyright Owner

Nathan Theodore Burdine

Language

en

Proquest ID

AAIDP12025

File Format

application/pdf

File Size

43 pages

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