Initiation from a point anode in a dielectric liquid

Many previous studies of electrical breakdowns in dielectric liquids in point-plane geometry have examined the relationships among the breakdown structure (or speed), the electrode geometry (point radius, gap length), and/or voltage. This paper explores the hypothesis that, for streamers initiating from a point anode, the critical volume model used for similar geometry in gaseous dielectrics is useful in liquids. The assumption of the critical volume is shown to be consistent with experimental data. Specifically, a critical volume of 0.4-1.0 mum ³ is consistent with the location of streamer initiation, with the independence of the initiation voltage for the 2nd anode mode from the tip radius for sharp tips, and the measured free paths of electrons in cyclohexane for the energies of interest