Field Emission From Polymers Relevant to Anode-Initiated Flashover Development

Pulsed electron field emission is measured from an assortment of plastic insulators with various surface preparations. The emission is markedly stochastic in nature. Generally, there is a spatially diffuse, baseline level of emission which is observed after a few repeated pulses on a sample. Additionally, localized, highly emissive sites contribute sporadically, with the estimated current for those excitations sometimes exceeding the baseline emission by orders of magnitude. Under 40 ns pulse excitation, Rexolite® produces measurable currents spanning from tens of nA up to hundreds of μA. These measurements mark a first step towards understanding initial plasma formation in anode-initiated vacuum flashover.