Statistical behaviour of dielectric discharges on satellites : a new experimental approach

Polymeric insulating layer may show propagating surface discharges when they are irradiated under vacuum with high energy electrons. Such discharges could create electromagnetic interferences on geosynchronous spacecraft during magnetic storms. These discharges can be triggered at a defect zone or at the edge of the sample or following the electrical breakdown of the material. The values of the onset potential Vs, obey a statistical law which may be described by the Weibull distribution function. The characteristic parameters of the discharge (current intensity, velocity...) will present the same statistical behaviour. The same distribution can be used to statistically describe it in the case of a power law function of the parameter with the potential. In this paper we have analysed the measurements of linear discharge propagation velocity obtained by Balmain et al. (1982) on different materials. We have shown that these values were distributed in accordance with a Weibull function. The following general expression may be set for the velocity of the discharge, W: W = 03B1(Vs-V0)03B3. Such a relationship had already been determined in the case of negative (03B3 = 1) or positive (03B3 1) surface discharges at atmospheric pressure in air. An experimental approach is then proposed to evaluate the statistical laws governing the main parameters of the e-irradiated dielectric discharges. Revue Phys. Appl. 21 (1986) 817-824 DÉCEMBRE 1986, Classification Physics Abstracts 92.60P