Time-resolved current-voltage measurement of the spark breakdown in liquid n-hexane

Measurements of the temporal variation of voltage and current in the spark discharge of liquid n-hexane were carried out. A dc-voltage, which increased linearly in time, was applied to a test cell with tip-plane electrode geometry. By careful mechanical design of the test cell a defined wave impedance of the whole experimental set-up was realized. A capacitive voltage divider was integrated into the high voltage feed to the tip electrode and the plane electrode was connected to ground via a coaxial measuring resistor. Data were taken for 1 mm and 2 mm electrode separation and for both polarities of the tip electrode. The temporal variation of the spark resistance R(t) was calculated and a general equation for R(t) was derived.