Large air-gap discharge and Schlieren techniques

In Part one, the formation and development of leader filaments in large air-gap discharges are studied by Schlieren techniques. The time evolution of the thermal diameter of the leader at a given point in space is studied for several gap spacings ranging from 1 to 16.7 m and for different wave forms and voltage levels. In Part two, the authors review the main phases of the positive leader development. Experimental results obtained by Schlieren methods are used to test previous models of leader behaviour. Information is obtained about reduced field values and neutral temperature values in the leader channel.