High field conduction and breakdown in aprotic liquids

The formation or presence of small bubbles from various sources plays an important role in the high field conduction and breakdown phenomena in hydrocarbon insulating liquids.1,2,3 The possibility of observing electron multiplication or Townsend α-processes is diminished by the presence of such bubbles which provide a competing gas phase in which electron avalanches develop relatively easily. Energetic electron processes may also be impeded by the presence of C-H bonds whose vibrational excitations provide a favorable energy loss mechanism for electrons.4 The eventual breaking of these bonds can also result in the evolution of hydrogen5 which can serve as one of the sources of gas bubbles.