A Novel System for the Study of Insulator Prebreakdown

In our laboratory we have constructed a pre-bulk breakdown apparatus, in vacuum, in which to study commercially available samples of polycarbonate, acrylic, and polyacetal. The system consists of a Marx generator, inductor, high voltage vacuum bushing, and a needle-plane electrode geometry. Through the use of the inductor and needle, fields in excess of 1 MV/cm can be obtained. Detection of the microscopic precursors to puncture in the samples requires a highly sensitive diagnostic. Laser induced fluorescence using fluorescent probes will locate and characterize the precursors.