PHENOMENON OF SKIPPING SPARKS IN DISCHARGES ON A DIELECTRIC SURFACE

Gliding sparks are associated with channel breakdown in air near a cor ona precharged dielectric layer backed by ground. Characterized by hig h current, their bright channels usually end in sudden branching/dimmi ng. Infrequently, there occur cases in which channel brightness is int errupted, with no evident local branching but a new leader continuing on propagating after momentary delay. This skipping-spark phenomenon h as been studied in an experimental system intended for taking Kirlian photographs. Operated in a Lichtenberg-figure mode, the method yields evidence in some detail. We report on observations of spark-channel to uchdown and subsequent rebounding. A model based on nonuniform surface charging is proposed for explanation.