Positive streamer inception in cyclohexane: Experimental characterization and cavitation mechanisms

摘要

This paper deals with physical processes involved during inception of positive streamers in liquid cyclohexane. The inception of streamers is detected with a high temporal resolution by measurements of charge, visualization, and detection of phase change by scattered laser light. These techniques allow us to obtain measurements of inception voltages and inception delay time in various conditions of impulse voltage with different slew rates, and pressure. In positive polarity, a minimum "formative time" close to 40 ns is observed, as well as a large influence of both pressure and slew rate. The hypothesis of cavitation induced by the EHD motion, and liquid boiling due to heat dissipation are considered to explain positive streamer inception.