Experimental observation of high-voltage, low-current vacuum arcs

A poorly explored type of discharge has been investigated in high vacuum (10/sup -7/ to 10/sup -6/ torr), with a DC high voltage across 0.2- to 0.8-mm gaps. The discharge has been found to be quite different from other widely known types of vacuum and gas discharges by the combination of its voltage-current characteristics (hyperbola-type), source and carriers of current (mostly electrons), and spatial potential distribution (a considerable electric field across the gap and a steep potential fall near the cathode).