Features of the arc binding region structure on the surface of the thoriated cathode in atmospheric pressured argon

Abstract

The parameters of a non-pulsed dc arc discharge of atmospheric pressure in argon were experimentally studied, and the chemical composition of the cathode surface in the arc binding zone was studied. The measurements were performed for thoriated tungsten cathodes (W-2% ThO2) for currents of 200 and 300 A. During the operation of the plasma torch, the temperature and electron concentration in the positive column and the surface temperature of the cathode were measured. A computational and theoretical analysis was performed on the distribution of current density and electric field strength in the arc binding zone. As a result, three fundamentally different zones of the arc binding area were identified, and their size and chemical composition were determined.