Injection current and the formation of bubbles in strong, very nonuniform electric fields

The flow problem of a nonstationary current upon injection from a spherical electrode is solved. It is shown that the field distribution can have a maximum that is displaced in the direction from the electrode with the velocity of the injected-charge front. The formation of bubbles in pre-breakdown electric fields is analyzed and it is shown that the bubbles can form in dielectric liquids without ionization under the action of high voltage.