During the March 20-22, 1990, magnetic storm, Millstone Hill radar and DMSP satellite observations detailed the conditions surrounding the occurrence ofa SAR arc which was observed continuously through an 8-hour interval from dusk till past midnight in the North American sector. All-sky imaging with a 630.0-nm imager continually monitored the two-dimensional position and magnitude of the SAR ar...

Ever since conception of the vacuum arc centrifuge in 1980, periodic fluctuations in the ion saturation current and floating potential have been observed in Langmuir probe measurements in the rotation region of a vacuum arc centrifuge. In this work we develop a linearized theoretical model to describe a range of instabilities in the vacuum arc centrifuge plasma column, and then test the validit...

An efficient modified arc plasma method, where a focusing electric field is superimposed on the arc electric field, is optimized for the bulk generation of highly pure multi-walled carbon nanotubes (MWNTs). Raman spectroscopy and thermogravimetric measurements have been used to optimize the process. It was found that, at the optimized focusing field configuration, this process can utilize about...

Pattern formation and self-organization are phenomena commonly observed experimentally in diverse types of plasma systems, including atmospheric-pressure electric arc discharges. However, numerical simulations reproducing anode pattern formation in arc discharges have proven exceedingly elusive. Time-dependent three-dimensional thermodynamic non-equilibrium simulations reveal the spontaneous fo...

The conventional wisdom about solar array arcing in LEO is that only the parts of the solar array that are swept over by the arc-generated plasma front are discharged in the initial arc. This limits the amount of energy that can be discharged. Recent work done at the NASA Glenn Research Center has shown that this idea is mistaken. In fact, the capacitance of the entire solar array may be discha...