The role of space plasma simulation chambers in spacecraft design and testing

Space plasma simulation chambers have been used, since the earliest days of the space program, to investigate the effects of the space plasma environment on spacecraft systems. A space plasma simulation chamber is a vacuum chamber capable of producing and retaining a high vacuum (10/sup -6/ to 10/sup -5/ torr) during operation of a plasma source capable of producing a plasma of up to 10/sup 6/ electrons and ions per cubic centimeter. Usually, the chamber must be large enough that plasma effects on the spacecraft systems or subsystems to be tested will not be influenced directly by the plasma source or the chamber walls. This means that the chamber must be several times the size of the plasma sheath surrounding the sample even when it is biased to high voltages relative to the surrounding plasma.