Bubble Generation in Liquid Hydrocarbon in Divergent Fields

The conduction current I c and the photocurrent I p were measured in hydrocarbon liquids subjected to d.c. divergent fields. Space-charge limited currents were observed in clarified ionic carrier of both polarities produced by electron attachment. The linear relation between I p and I c indicated that molecules were excited by injected electrons before the attachment. In liquid methane in negative point electrode, I p and I c were reduced by a rise in pressure, giving evidence for the existence of gaseous bubbles during discharge. However in pentane and hexane, both currents were independent of pressure. The difference is probably caused by the bubble growth rate; the rate is probably larger in liquid methane.