Electrohydrodynamic instability and electrical discharge initiation in hexane

An experimental technique is described that tests the hydrodynamic stability of the fluid boundary in a fluid-insulated system: A quasi-uniform field configuration is used and a pulsed, Nd:YAG laser is employed to create a micro-bubble at the surface of one electrode. The gap is pulse-charged and the laser is synchronized with the time-of-application of the voltage pulse. Under appropriate experimental conditions of voltage and laser pulse energy, the bubble evolves to produce full electrical breakdown by the onset and propagation of instabilities in the bubble surface. Experimental data obtained in hexane are presented.