Radiation effects in satellite cables

A combined experimental and analytical study was made of the mechanisms which determine the response of satellite cables to X-rays. Parameters investigated include gaps, with and without trapped air, polymer type, stored charge effects introduced by manufacturing or handling, trapping of space electrons in the dielectric, radiation conductivity, sample-to-sample and manufacturer-to-manufacturer variations, and dose effects. It was found that the principal mechanism enhancing response was the presence of gaps between conductors and dielectrics which are naturally present in braided shield cables and can be introduced by bending in semirigids. The presence of stored charge was less significant. An equilibrium distribution of trapped electrons will be built up in a period of about one-half hour for the artificial trapped environment and in about 20 days in the natural space environment, which will obliterate any previously stored charge. The so-called first pulse anomaly will occur only when one has a cable containing air filled gaps. In this case, the first shot rather than the nth shot response will be most typical of cable behavior.