Session 7P - Plasma Applications and Plasma Technology.
POSTER session, Thursday morning, November 14
Exhibit Hall - Concourse Level, Adam's Mark
We have spectroscopically investigated(This work was supported by the U. S. Department of Energy.) a miniature electrostatic plasma source--a plasma gun [G. Fiksel et al., Plasma Sources Sci. Technol. 5, 78 (1996)]. The gun functions as a clean source of high density (10^19 - 10^20 m^-3), low temperature (5 - 15 eV) plasma. A key result is that molybdenum from the gun electrodes is largely trapped in the internal gun discharge; only a small amount escapes in the plasma flowing out of the gun. In addition, the gun plasma parameters actually improve (lower impurity contamination and higher ion temperature) when up to 1 kA of electron current is extracted from the gun via the application of an external bias. This improvement occurs because the internal gun anode no longer acts as the current return for the internal gun discharge. The gun plasma is a virtual plasma electrode capable of sourcing an electron emission current density of 1 kA/cm^2. The high emission current, small size (3 - 4 cm diameter), and low impurity generation make this gun attractive for a variety of fusion and plasma technology applications.