Role of dissolved gases on the high field luminescence pattern of polyethylene

Abstract

An experimental setup has been developed to study prebreakdown phenomena in dielectric materials under controlled conditions. A highly sensitive photon counting system coupled with a lens system detects the threshold field for light emission as a function of the nature of the gas. The samples are located in a chamber in which the pressure can be varied from 5.10/sup -7/ to 2.10/sup +3/ torr. Some results are presented concerning the influence of the nature of the gas dissolved in polyethylene samples on the electroluminescence threshold field and light pattern. The presence of electronegative gas molecules in the sample strongly affects the observed behavior by changing the volumetric and interfacial conditions. Good agreement is found between the values of the threshold field for light emission reported and those by other workers if the sensitivity of the detection systems is considered.<>