Generation and characterization of micron and sub-micron particulate using an electrothermal source

Summary form only given. The Surface Interaction Research Experiment at N.C. State (SIRENS) produces a pulsed (/spl sim/100 ms), low temperature (0.1- 3 eV), high density (10/sup 13/-10/sup 19/ cm/sup -3/), flowing plasma by ablating a liner material. As the plasma expands and cools, micron and sub-micron particles develop from the liner material. This study examines the size of the particulate generated and the associated plasma parameters for copper, aluminum, copper-aluminum, and polycarbonate liner materials at several locations downstream from the source for a 5.8 kJ input energy. The plasma is characterized using optical emission spectroscopy under the LTE assumption and Stark broadening of the H/sub /spl alpha// line and neutral copper lines, which are always present in the source. All linear materials produce a plasma with an electron temperature on the order of 0.5 eV with a range of electron densities between 10/sup 16/ and 10/sup 18/ cm/sup -3/ at all the downstream locations. The particulate was collected on a series of copper, stainless steel, woven, or non-woven fabric substrates for analysis. copper particulates collected on woven fabric. All the substrates showed spherical particles, but the metallic substrates showed evidence of short fibers developed from the liner material. The particles are characterized by scanning electron microscopy coupled to software capable of calculating particles´ sizes. The analysis shows a range of particle sizes from 0.1 micron to 10 micron. By using EDX analysis, the composition of the droplets was determined. The composite copper-aluminium liner produces particles composed of both copper and aluminum without a visible separation of the materials.