Nanosecond Breakdown in Hexane

The electrical breakdown of hexane was investigated using nanosecond duration high-voltage pulses. An attempt was made to experimentally isolate the formative time lag contributions of the two major breakdown mechanisms: electron avalanche and streamer processes. The electrode area was kept constant at 2.85 cm2 throughout the study, and time resolution was on the order of 0.5 ns. The gap spacing and the applied field were varied in a highly controlled manner. A series of breakdown events were studied for gap spacings ranging from 0.07 to 0.41 cm with selected constant field strengths from 0.8 to 1.6 MV/cm. The results obtained indicate that the streamer mechanism is the dominant process in the breakdown of hexane and the average velocity of propagation is on the order of 107 cm/s for the fields and gap spacings used in this study.