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Experimental study of plasma wave resonances in a hot nonuniform plasma column

Citation

Nickel, John C. (1964) Experimental study of plasma wave resonances in a hot nonuniform plasma column. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-10182002-102050

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The relative frequency spectrum [...] of plasma wave resonances in the positive column of a low pressure mercury discharge tube has been shown to depend upon the parameter [...] where r[subscript w] is the radius of the column, [...] is the Debye length defined in terms of the average electron density, and [...] is the square of the average plasma frequency. This paper presents observations of both dipole and quadrupole resonance spectra made on several discharge tubes with r[subscript w] ranging from 0.30 to 0.87 cm. For these measurements [...] varies from about 10[superscript 2] to 10[superscript 5], and the best fit electron temperatures are found to be of the order of 3 ev. The average electron densities are directly measured using a cavity perturbation technique. The results of these observations are found to be in good agreement with the theory (1,2) based upon the first two moments of the correlationless Boltzmann equation in conjunction with Parker's electron density profile (3) for a low density positive column. The results of a preliminary investigation of the effects of an axial, static magnetic field on the dipole resonance spectrum are also presented. These results indicate that in the presence of an axial magnetic field not only does the lowest resonance (approximately predicted by the cold plasma theory) split, but the next higher order resonance also splits. For the lowest resonance, it is found that [...], while for the next higher order resonance [...], where [...] is the cyclotron frequency. These preliminary results are in good accord with calculations made by Parker (1), again using the moment equation approach. (1) J.V. Parker, PhD Thesis, California Institute of Technology, June 1964. (2) J.C. Nickel, J.V. Parker, R.W. Gould, Phys. Rev. Letters 11, 183 (1963). (3) J.V. Parker, Phys. Fluids 6, 1957 (1963)

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gould, Roy Walter
Thesis Committee:
  • Unknown, Unknown
Defense Date:27 May 1964
Record Number:CaltechETD:etd-10182002-102050
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-10182002-102050
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4153
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:21 Oct 2002
Last Modified:17 Jul 2014 19:59

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