A STUDY OF THE MEAN CHARGE CONSUMPTION OF LONG SPARKS IN AIR AS A FUNCTION OF THE GAP LENGTH AND THE IMPULSE SHAPE

The charge consumption of positive and negative spark gaps developing under biexponential voltage impulses under critical conditions, namely the minimum breakdown voltage at the critical time to crest, is analy sed. It is shown that the increase of the leader's charge consumption is not linear with the gap length and neither is the leader's charge c onsumption per axial unit of the leader's length. This behaviour can b e attributed to two terms: the first one (a creation term) due to the growth in length of the leader and a second one (a maintaining term) d ue to the necessity of maintaining the physical properties of the lead er during its propagation. The values of the corresponding constants f or positive and negative polarities are given. The influence of the sh ape of the impulse on the charge consumption by positive and negative leaders is discussed. The notion of U curves for the consumption of th e discharge is pointed out.