Electrical conductivity and total emission coefficient of air plasma.

Abstract

The electrical conductivity, o-, and the total radiant power per unit volume, PR9 of air are measured for temperatures between 8,000 and 12,500°K at atmospheric pressure. The measurements are made in a wallstabilized electric arc discharge which produces a pure, stable plasma. Axial electric field strength, £,, and azimuthal magnetic field intensity, B^ are measured as functions of the discharge radius by using probe techniques. Current density, jz9 is obtained as ~]*= V x£//z0, and electrical conductivity is determined by using Ohm's law, o = jJEz. PR is measured with a total radiation thermopile and also by using an electrical technique. Plasma temperature is determined from the absolute intensities of the 4935 A NI and 4368 A OI lines.