A new microwave technique has been developed for the experimental study of small amplitude surface waves on an electrically conducting fluid. The fluid forms one of the walls of a resonating, microwave cavity. Surface waves with amplitudes as small as 10⁻³ cm. can be measured by observing the resulting change in the resonant frequency of the cavity. This technique has been successfully used to measure the viscous and magnetic damping coefficient of a small amplitude, standing, surface wave in liquid mercury. The magnetic damping, coefficient (for a vertical, magnetic field) was found to be in good agreement with a calculation that was made, for low magnetic Reynolds numbers. When the viscous damping coefficient was compared with the standard theory, which allows horizontal motion of the. surface, a disagreement of up to a factor of four was found. It, however, showed excellent agreement with a modified theory which assumes that there, is no horizontal motion of the surface. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

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Call number: LD2668 .T4 1963 R47 / Master of Science

published_or_final_version / Physics / Master / Master of Philosophy

A non-contact method characterizing the quantum efficiency of a solar cell using the microwave reflectance signature is presented in this thesis. Traditional solar cell quantum efficiency (QE) measurements are only possible near the completion of the fabrication process using contacts in direct physical connection with the metalized surface tabs to probe and extract charge carriers from the device. However, pressure within the solar metrology industry to report the spectral performance of the device earlier in the manufacturing process as part of the process control loop requires that a new non-contact method be developed. This thesis work contributes the development of a non-contact focused microwave reflectance technique capable of acquiring the full 365nm - 1100nm spectrum in under 1 minute. Unlike many similar Time Resolved Microwave Conductivity (TRMC) and Microwave Photoconductivity Decay (µPCD) systems based on the open-ended waveguide technique, this measurement is developed to perform measurements in the far-field. As such, a different mechanism for understanding the problem is presented using the modulated scatterer concept from antenna theory. Using a combination of high dielectric sensor pads and negative-index of refraction microwave lenses, we are able to tune the far-field field probe size from 5mm-150mm allowing for high speed single point in-line measurements or high spatial sensitivity laboratory measurements.

No description available.

Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Mohammed Nurul Afsar. Submitted to the Dept. of Electrical Engineering. Includes bibliographical references (leaves 183-192). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 150-156).

Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 50-51).