A space simulation chamber for space power insulation

Abstract

An account is given of an experimental facility which has been designed specifically for the study of electrical insulation in a simulated space environment. Insulation in space can experience a very wide range of environmental stimuli and it is very difficult if not impossible to stimulate them all. Those that are considered in the present work are vacuum, temperature, nuclear radiation and atomic oxygen. The facility consists of a stainless steel high-vacuum chamber with a sample mounting arrangement which allows sample temperatures to be varied between 80 and 470 K. Test specimens can also be exposed to electromagnetic radiation within the chamber. Atomic oxygen treatment of materials takes place before they are introduced to the chamber. The materials being considered are Kapton and an epoxy resin formulation. Various electrical measurements are being undertaken and comprise primarily dielectric loss by frequency domain spectroscopy and pre-breakdown current pulse activity under direct stress, while the provision exists for conductivity and breakdown measurements as well. These are made in real time under vacuum, temperature and low dose rate electromagnetic radiation following an ageing procedure which involves combinations of these three foregoing environmental stimuli and atomic oxygen.