Experimental investigation of the anode region of a free-burning atmospheric-pressure inert-gas arc I. General characteristics of the discharge. Low-current regime

Abstract

This paper reports the experimental investigation of the anode region of a free-burning inert-gas arc at atmospheric pressure in the current range from a few amperes to hundreds of amperes. The tungsten thermionic-emission cathode and the large-diameter water-cooled copper anode that were used permitted the anode arc root to assume its natural form. The general characteristics of the discharge are given and results are presented from investigations of the anode region at low currents, where the anode arc root is single and constricted, but erosion-free. Measurements of the plasma parameters as well as the current density in the arc root are reported, and a comparison is made between the values obtained and those characteristic of the region of the cathode arc root.