The basic characteristics of a vacuum arc are investigated with a special electrode whose cathode consists of two half-disks. Pure copper is used for one part of the cathode, while copper, chromium, silver, and titanium are used for the other part. The tested arc current value is less than 4000 A, and the flux density of the axial magnetic field applied to a vacuum arc is less than 0.015 T. Experimental results show that the arc voltages of dual-part cathode electrodes are much lower than those of the individual pure metals, and that current sharing between the two parts is roughly determined by the arc current-voltage characteristics of the metals. The arc voltage of the dual-part cathode electrode is extremely low when the current is less than 1000 A.
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