Development of discharges in liquid nitrogen in non-uniform electrical field

Abstract

This paper reports the results of measurements of the dielectric strength of liquid nitrogen and of investigations of prebreakdown phenomena and the development of discharges at large point-plane and point-sphere electrode gaps. The tests were carried out under alternating and direct voltage conditions as well as with voltage pulses of 250/1250 μs of both polarities. It has been found that there are marked differences in the development of discharges and the formation of a gaseous phase, depending on whether the polarity of the point electrode is negative or positive. With the point negative, a very strong space charge effect on the development of the main discharge becomes manifest, due to space charge generated during the stage of prebreakdown discharges.