Bubble model: time dependent pressure effect in liquids

A model of prebreakdown processes based on discharges in bubbles which lead to bubble deformation and field increases in the vicinity of bubble poles is presented. Breakdown occurs when the field near a bubble has reached a critical value. According to the model, breakdown pressure dependence is altered when the pulse duration is decreased. If breakdown occurs at a pulse duration of less than 1 μs, the electrical strength dependence on pressure is very weak. This is explained by bubble elongation over a short period of time, leading to a considerable increase of Coulomb forces, in turn producing a decrease of the role of external factors in the resulting action on the bubbles