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An Experimental Study of Compressional Hydromagnetic Waves


Swanson, Donald Gary (1963) An Experimental Study of Compressional Hydromagnetic Waves. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/XBT0-FD96.


An experiment is described in which a compressional hydromagnetic wave is observed in a hydrogen plasma-filled waveguide. The theory of a cool, partially ionized, resistive plasma in a magnetic field is described briefly and expressions are derived for the dispersion relation and transfer function which include both the propagation and attenuation constants as a function of frequency. Measurements of the cutoff frequency are presented which verify its linear dependence on the magnetic field, and they show good agreement with theory on the variation with the ion mass density. The impulse response of the plasma is studied, transformed into the frequency domain, and quantitative comparisons are made with the theoretical transfer function to determine the degree of ionization, the resistivity, and the ion-neutral collision frequency.

Results indicate that the degree of ionization varies over a range from 75% to 45% when the initial density changes from 1.3 • 10^(21) to 1.4 • 10^(22) atoms/m^3. The measured resistivity appears to increase with the magnetic field, with the mean value corresponding to a temperature of the order of 5 • 10^3 °K. The average value of the product of the charge exchange cross section and the neutral thermal speed is found to be approximately (5.5 ± 1.3) • 10^(-15) m^3/sec.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics)
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:1 January 1963
Record Number:CaltechTHESIS:05172012-132525991
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7041
Deposited By: Tony Diaz
Deposited On:18 May 2012 18:04
Last Modified:09 Jan 2024 00:52

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