Electrical treeing

In electrical engineering, treeing is an electrical pre-breakdown phenomenon in solid insulation. It is a damaging process due to partial discharges and progresses through the stressed dielectric insulation, in a path resembling the branches of a tree. Treeing of solid high-voltage cable insulation is a common breakdown mechanism and source of electrical faults in underground power cables.

A 3D “Electrical Tree” (or Lichtenberg figure), imbedded within a 1.5″ cube of Polymethyl Methacrylate (PMMA)