Accession Number : ADP005706

Title :   Radiation Charging and Breakdown of Insulators,

Corporate Author : ERA TECHNOLOGY LTD LEATHERHEAD (ENGLAND)

Personal Author(s) : Davies, D. K.

Report Date : MAY 1987

Pagination or Media Count : 7

Abstract : An experimental investigation of the charge produced by photo-emission from insulators in vacuo is described. It is shown that the emission from materials commonly used in spacecraft construction, such as polyimide, is well described by solid state theory but that externally applied fields modify both the emission dynamics as well as the eventual saturation charge density. The energetics of the electrical breakdown of such charged surfaces is analysed. Surface discharges can, of course, cause degradation of the quality of the insulation through erosion, puncture or formation of electrically conductive, carbonised tracks, producing concomitant reduction in electrical system performance. These processes, which result directly from chemical interaction or indirectly, thermally, are reviewed and means of minimising the effects discussed. Avenues of further investigation are outlined.

Descriptors :   *BREAKDOWN(ELECTRONIC THRESHOLD), *ELECTRIC CHARGE, *DIELECTRICS, INSULATION, SPACECRAFT COMPONENTS, IONIZING RADIATION, ULTRAVIOLET RADIATION, EMISSION, SURFACE PROPERTIES, SILICON DIOXIDE, POLYMERIC FILMS, NYLON, POLYVINYL CHLORIDE, POLYCARBONATES, POLYETHYLENE TEREPHTHALATE, POLYIMIDE PLASTICS, ELECTRIC DISCHARGES, GREAT BRITAIN.

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE