High Field Conduction Currents in Hexane

Abstract

The author has been able to measure conductivity currents in hexane up to the breakdown stress by using a conditioning process which enables a stable state of the electrodes and liquid to be kept for many hours. It is shown that the results are consistent with a theory of electron emission from the cathode, and that the dominant process is the Schottky one, together with the mathematically similar barrier peak tunnelling component. The work function is found to be 1.0 to 1.2 eV, although this may contain a bulk liquid component. For stresses of 1 MV cm-1 and greater, evidence is given of an ionization process within the liquid. Due to the difficulties of analysis, caused by the use of spherical electrodes, no estimate of the ionization increment factor α can be given. The tests give no information on the possibility of transient changes in the cathode state due to its inability rapidly to neutralize ionized particles reaching it.