Silicon P-N Junction Radiation Detectors for the Telstar® Satellite

This paper describes the development and testing of the silicon p-n junction nuclear particle detectors which have been ued in the radiation experiments of the TELSTAR® communication satellite, and the Relay and Explorer XV satellites. The sensitive element of the detector is a diffused mesa diode of 10,000 to 20,000 ohm-cm p-type silicon. It is encapsulated in a transistor-type can with a thin (0.3 mil) Kovar window. In spite of the encapsulation, surface reliability was a major development problem. An extensive reliability testing program revealed several types of surface instability. Nevertheless, a high degree of reliability was achieved in most of the detectors, including those which were used on satellites.