A SPACE SIMULATION CHAMBER FOR SPACE POWER INSULATION

An account is given of an experimental facility which has been designe d specifically for the study of electrical insulation in a simulated s pace environment. Insulation in space can experience a very wide range of environmental stimuli and it is very difficult if not impossible t o stimulate them all. Those that are considered in the present work ar e vacuum, temperature, nuclear radiation and atomic oxygen. The facili ty consists of a stainless steel high-vacuum chamber with a sample mou nting arrangement which allows sample temperatures to be varied betwee n 80 and 470 K. Test specimens can also be exposed to electromagnetic radiation within the chamber. Atomic oxygen treatment of materials tak es place before they are introduced to the chamber. The materials bein g considered are Kapton and an epoxy resin formulation. Various electr ical measurements are being undertaken and comprise primarily dielectr ic loss by frequency domain spectroscopy and pre-breakdown current pul se activity under direct stress, while the provision exists for conduc tivity 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 th ree foregoing environmental stimuli and atomic oxygen.