The Effect of Electrode Contamination on the Properties of Air-Arc Plasmas

摘要

The plasma test environments originating from arcs are usually contaminated with material from the arc electrodes. Carbon electrodes contribute appreciable quantities of vapor which alter the chemical composition and thermodynamic properties of the jet and cooled copper electrodes contribute trace quantities of vapor which, as expected, alter the character of the electrical discharge. In this work, the chemical composition and thermodynamic properties of air are compared to those of air-carbon gaseous mixtures containing l-30%carbon by weight. The comparison of the different environments is made over the temperature range 4000-10, 000°K and pressures between 0.1 and 100 atmospheres.nThe effects of trace amounts of copper on the electrical conductivity and power dissipated in the air arc column are calculated.