Thesis--University of California, Berkeley, 1960. / "Controlled Thermonuclear Processes, UC-20" -t.p. "TID-4500 (15th Ed.)" -t.p. Includes bibliographical references (p. 13).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. Description based on print version record. Includes bibliographies.

Thesis (Ph.D.) - University of St Andrews, May 2009.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 129-132).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

No description available.

The perturbation in a glow discharge in hydrogen is studied theoretically and experimentally. In an ordinary glow discharge a perturbation has been produced by applying a small sinusoidal high frequency electric field. This modulates the electron energy and hence the number density of atoms in excited states; The relative phase and amplitude of light emitted in the first four lines of the Balmer series have been measured. A theory based on the work of Bates et al, is developed in this thesis and the results predicted give better agreement with the experimental values than do alternative theories which have been published recently. These if absorption of line radiation by the discharge is shown to have a critical effect on the behaviour of the plasma. The limitations and validity of assumptions are discussed and a modified experiment is suggested. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A "gradient probe" consisting of two search coils has been developed to measure the current density in a pulsed plasma. This probe measures both the magnitude and the gradient of the magentic field simultaneously enabling more accurate measurements than the conventional magnetic probe which has only one coil. It has been used to measure the current densities and the magnetic fields in z-pinch discharges in helium at pressures between 500μ and 4 mmHg. The collapse curves obtained agreed with the predictions of a modified snow-plow equation which allowed for the loss of particles from the collapsing current shell. The flow of current in the plasma is distorted by the presence of a probe. Such an effect spoils the spatial resolution so that the measured values of the current density Jp are averages of the true current density J₀ over a finite region. To investigate this, a correction formula which relates Jp to J₀ has been developed. Our error analyses showed that any scatter in Jp due to experimental errors was magnified twenty times in J₀. For a pulsed plasma, therefore, one should try to reduce the perturbation of the probe instead of relying on the correction procedure. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Plasmas confined by a dipole magnetic field exhibit interchange and entropy mode turbulence causing bursty intermittent transport of particles and energy [1]. On the Collisionless Terrella Experiment (CTX), this turbulence is dominated by low-frequency, long-wavelength modes with amplitudes and phases that vary chaotically in time [2]. We present a new paradigm for characterizing this turbulence by measuring the time-evolution of the fluctuation power spectrum and the instantaneous bispectrum using the continuous wavelet transform [3, 4] and computing the statistical properties of turbulent wave kinetics. We observe that both the fluctuation power and the energy transfer by three-wave coupling, or bispectrum, between these fluctuations can be intermittent. When antenna are used to actively launch waves into the turbulence, the intermittency of the driven waves decreases, while the intermittency of other waves increases. Similarly, application of active feedback [5] to amplify the turbulence decreases the intermittency of the wave energy, while suppressing feedback increases this intermittency. Measurements based on this new paradigm show that the transfer of wave energy to larger and smaller scales in a turbulent plasma is not steady but occurs in short and intense bursts, analogous to the better-known short bursts of particle transport in magnetized plasma.