Accession Number : ADP005705

Title :   Arc Propagation, Emission and Damage on Spacecraft Dielectrics,

Corporate Author : TORONTO UNIV (ONTARIO) DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Balmain, K. G.

Report Date : MAY 1987

Pagination or Media Count : 7

Abstract : This paper reviews the literature of arc discharges on spacecraft dielectric materials which have become charged by energetic electrons and ions. The results are mainly from laboratory measurements of the properties of these arc discharges. Arcs resulting from the charging of spacecraft dielectrics can be extremely strong because the charge over a large area is mobilized through the phenomenon of arc propagation. The resultant damage patterns on the dielectric are shown to be related to the arc patterns, and to the optical anisotropy and crystallinity of the material. The evidence for dielectric melting is suggestive of likely contamination of nearby surfaces. The effectiveness of arc barriers sheds light on arc propagation mechanisms. Coupling to external circuits can be deduced from blowoff calculations and from near-field measurements of arc currents. Exposed dielectric edges and surface metallization in strips and patches contribute to charge accumulation and arc triggering. Broad-spectrum, high-energy incident electrons can cause charging and discharging internal to the spacecraft.

Descriptors :   *ELECTRIC ARCS, *DIELECTRICS, ELECTRIC DISCHARGES, SPACECRAFT, ANISOTROPY, OPTICAL PROPERTIES, PROPAGATION, MELTING, CONTAMINATION, BARRIERS, EDGES, ELECTRONS, HIGH ENERGY, DAMAGE, COUPLING(INTERACTION), LITERATURE SURVEYS, CANADA.

Subject Categories : Electricity and Magnetism
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE