arc discharge, <in a gas or in a vapour>
electric arc, <in a gas or in a vapour>
Note 1 to entry: The emission of the cathode results from various causes (thermionic emission, field emission, etc.) acting simultaneously or separately; secondary emission plays only a small part.
Note 2 to entry: This entry was numbered 845-07-16 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-54 in CIE S 017:2011.