Internal space charge measurement for space environment monitoring

Dielectric materials used in space environment have been investigated in an irradiation chamber which reproduce spatial environment. Under irradiation, polymeric materials are able to store charges inside as well as on the surface. A new pulsed electroacoustic space charge measurement unit has been recently developed. It can be mounted in an irradiation chamber to perform measurements in situ. Thanks to this system it is possible to observe internal space charge accumulation of polymers under irradiation as a complement to the in situ surface potential measurement. In this paper, the new system is introduced with experimental results obtained on acrylic sheet. Additionally, a floating electrode was applied to examine the specimen configuration with various specimens, such as polyimide and fluoro-ethylene propylene. The combination of in situ observation of the surface potential and the internal space charge behaviour can give valuable information to investigate the materials used in the space environment.