Direct measurement of trapped-charge profiles in irradiated polymer films

Polymer films used in the space environment are frequently exposed to partially penetrating electrons and show therefore often long-lasting charge-trapping effects. The physical processes responsible for the charge buildup and decay can only be understood with an accurate knowledge of the spatial charge profiles within the dielectrics. While calculations of charge profiles in radiation-charged dielectrics have been attempted frequently [1-8], experimental data on thin-film polymers used in space applications are scarce [9-12] and sometimes not too reliable.