Title :
Fine structure of self-field-dominated plasma
Author :
Nardi, V. ; Powell, C.W.
Author_Institution :
Stevens Inst. of Technol., Hoboken, NJ, USA
Abstract :
Summary form only given, as follows. This extension of previous experiments addresses the estimate of the energy-density lower bound from the local-current lower bound and the ion energy in plasma structures held together by self-consistent fields. Contact prints of plasma structures impacting on a variety of solid targets are obtained via target exposure to plasma focus discharges at powering energy levels W=5 kJ and W=20 kJ (D/sub 2/ filling at 5 Torr). The fine structure is recorded via non-uniform distribution of etched ion tracks. Ion filters of variable thickness /spl delta/>25 /spl mu/m of mylar screen out D/sup +/ ions of energy <1.5 MeV from one type of targets. Targets of a second type (without filters) assess the energy distribution of low energy ions (E<100 keV) with space resolution better than 1 /spl mu/m. Impacting D/sup +/ ions saturate dangling bonds of the surface layers of the mono-crystal target. The visualization of plasma impacted areas is achieved via successive oxidation of earlier D-saturated bonds. Ions with E>1.5 MeV are confined within filaments with sharply defined boundaries of diameter /spl les/100 /spl mu/m, at a distance >25 cm from the end-of-anode region, from which the plasma structures are ejected. An estimate of the filament current is obtained from the magnetic field magnitude in the variable spacing between target and ion filter.
Keywords :
discharges (electric); fine structure; plasma collision processes; plasma diagnostics; plasma focus; plasma properties; plasma-wall interactions; 1.5 MeV; 100 keV; 100 mum; 20 kJ; 25 cm; 5 kJ; 5 torr; D; D/sub 2/; D/sup +/ ions; contact prints; dangling bonds; energy distribution; energy-density lower bound; etched ion tracks; fine structure; ion energy; ion filters; local-current lower bound; mono-crystal target; mylar; non-uniform distribution; plasma focus discharges; plasma impacted areas; plasma structures; powering energy levels; self-consistent fields; self-field-dominated plasma; solid targets; space resolution; target exposure; Energy resolution; Energy states; Etching; Filling; Filters; Plasma applications; Plasma confinement; Plasma displays; Target tracking; Visualization;
Conference_Titel :
Plasma Science, 1995. IEEE Conference Record - Abstracts., 1995 IEEE International Conference on
Conference_Location :
Madison, WI, USA
Print_ISBN :
0-7803-2669-5
DOI :
10.1109/PLASMA.1995.533532