Thermionic cathode parameters versus pressure in a sustained argon arc

Experimental data on the influence of the argon pressure on the performance of a rodlike thoriated-tungsten cathode in a sustained arc discharge are reported for the first time. The integral parameters of the cathode, namely, the electron work function, temperature, current density, and specific surface area of erosion at currents of 20–150 A in the pressure range 2.66 × 103−1.00 × 105 Pa, are measured. Taken together, these parameters provide comprehensive information about the operating conditions of the activated cathode. A significant influence of the pressure on the specific erosion of the cathode is noted.