Results of the Telstar Radiation Experiments

This article presents some of the results obtained from the radiation experiments on the Telstar satellite. It describes the distribution of several classes of energetic charged particles mapped out by these experiments, and the integral radiation exposure of the satellite in orbit which has been calculated from these distributions. It also describes the radiation damage effects observed directly on semiconductor devices carried by the satellite and compares the damage with t h a t to be expected on the basis of the orbital integrals. 1505 1506 TIIE B E L L SYSTEM TECHNICAL J O U R N A L , J U L Y 1903 1.1 Charged Particle Experiment As described in detail in an accompanying article, 1 there are four silicon p-n junction charged particle detectors 011 the Telstar satellite, three that measure the distribution of protons in space at different energies and one that measures the electron distribution and some simple properties of the electron energy spectrum. All four detectors are energy proportional devices, giving an electrical pulse-height response proportional to the energy deposited by a charged particle in the active volume of the detector. By adjustment of the active volume, the levels of pulse height examined, and the amount of absorbing material which must be penetrated by a particle in reaching the detector, it is possible to distinguish protons from electrons and put bounds on the particle energies. In the electron detector, particle pulses are sorted into four channels corresponding to deposition of different amounts of energy between 250 and 1000 Ivev in the detector.