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Full-Text Articles in Physics
The Effect Of Voltage Ramp Rate On Dielectric Breakdown Of Thin Film Polymers, Anthony Thomas
The Effect Of Voltage Ramp Rate On Dielectric Breakdown Of Thin Film Polymers, Anthony Thomas
Senior Theses and Projects
Electrical insulators are used in many applications in industry, education and the home environment. They work by keeping electricity contained. They are not however perfect and under stress can become ineffective. Every insulator has a dielectric strength, a measurement of how much electrical stress it can withstand. If the material is stressed beyond that strength the material will breakdown. Electrostatic breakdown is defined as “the abrupt irreversible drop in resistivity at high fields, often accompanied by destruction of the material” (See Fig. 1) [McGraw-Hill]. The point at which the material breaks down is called the electrostatic discharge breakdown voltage, or …
Effects Of The Evolution Of Spacecraft Surfaces On Secondary Electron Emission Andspacecraft Charging, R. E. Davies, John R. Dennison
Effects Of The Evolution Of Spacecraft Surfaces On Secondary Electron Emission Andspacecraft Charging, R. E. Davies, John R. Dennison
All Physics Faculty Publications
Spacecraft charging due to the natural plasma environment found in all orbits is known to produce many of the observed spacecraft anomalies and failures. A primary factor in adverse spacecraft charging is the secondary electron emission of differing materials on the spacecraft. Precipitating electrons and ions from the plasma to spacecraft surfaces can result in varying amounts of charge being released, depending on the secondary electron yield of the materials; this can lead to arcing between surfaces. NASA's Space and Environments Effects (SEE) program has recognized the need to improve their current materials database for modeling spacecraft charging and have …
Theoretical Study Of The Effect Of Ionospheric Return Currents On The Electron Temperature, Robert W. Schunk, Jan Josef Sojka, M. D. Bowline
Theoretical Study Of The Effect Of Ionospheric Return Currents On The Electron Temperature, Robert W. Schunk, Jan Josef Sojka, M. D. Bowline
All Physics Faculty Publications
An electron heat flow can occur in a partially ionized plasma in response to either an electron temperature gradient (thermal conduction) or an electron current (thermoelectric heat flow). The former process has been extensively studied, while the latter process has received relatively little attention. Therefore a time-dependent three-dimensional model of the high-latitude ionosphere was used to study the effect of field-aligned ionospheric return currents on auroral electron temperatures for different seasonal and solar cycle conditions as well as for different upper boundary heat fluxes. The results of this study lead to the following conclusions: (1) The average, large-scale, return current …
The Effect Of The Gradient-Drift Term On Type I Electrojet Irregularities, D. T. Farley, Bela G. Fejer
The Effect Of The Gradient-Drift Term On Type I Electrojet Irregularities, D. T. Farley, Bela G. Fejer
Bela G. Fejer
We hypothesize that type 1 VHF radar echoes can only be observed when the electrojet plasma is linearly unstable at half the radar wavelength and that further, for reasons not yet understood, the phase velocity of the unstable waves always corresponds to the threshold conditions for instability, even when the destabilizing forces (electron drift and plasma density gradient) exceed the threshold. This phase velocity, which produces the Doppler shift of the radar echoes, is usually close to the ion acoustic velocity of the medium but can differ from it to some extent because of the effect of the density gradient. …