Study of Arc Mobility and Reignition in a Static Gap Discharge with Magnetic Field
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Motion of Magnetically Driven Arcs on Oxidized Electrodes
Experiments were carried out on a number of oxidized metals such as copper, brass, aluminum, and steel. Two kinds of rectangular electrodes were investigated, narrow and wide electrodes. On the narrow oxidized electrodes the arc moved slowly and sometimes discontinuously during its first run. During subsequent runs the arcs moved continuously along the same path of the first run with speeds which were ten times faster than the first run. On the wide oxidized electrodes however no slowdown of the arc was observed during its first run. It ran right away continuously with speeds similar to the subsequent runs.
Modeling Coherent Backscattering Errors in Fiber Optic Gyroscopes for Sources of Arbitrary Line Width
We present a new model of the noise and drift induced by coherent backscattering in a fiber optic gyroscope (FOG) interrogated with a light source of arbitrary temporal coherence. This study is critical to understand whether a FOG driven with a laser instead of a broadband source can attain high sensitivity and stability, which would have the overwhelming benefit of improving the FOG scale factor stability by at least ten-fold and would enable the use of FOGs for inertial navigation of aircrafts. Analytical and numerical solutions bring to light two significant new predictions. First, coherent-backscattering noise can be made negligibly small by utilizing a laser with a very narrow linewidth (less than ~ 20 kHz), although in this regime the drift is high. Second, by using a laser with a broad linewidth (greater than ~ 10 MHz), both the noise and the drift are low enough for aircraft inertial navigation. The dependencies of the noise and drift on fiber loss, loop coupling coefficient, and backscattering coefficient are also presented to define the optimum mode of operation of this new class of FOGs.