In-situ space charge distribution measurements in electron irradiated polymers for space applications

Electrostatic discharges caused by bulk charging in spacecraft insulating materials are considered to be a major cause of satellite anomalies. To prevent or to get a better control over the initiation of such an event, it is necessary to determine in more detail the nature and the bulk distribution of the charges that are injected in polymeric materials covering the satellites. A device based on pulsed electro-acoustic (PEA) detection technique has been adapted to perform space charge measurements during electronic irradiation in a vacuum chamber. Comparison between data obtained by theoretical calculations based on the stopping power range and data recorded in-situ on various polymeric materials with the new device show similar results. The possibility to measure the space charge (SC) distribution during irradiation opens the way to understand electrostatic discharge initiation mechanism. The analysis during relaxation should help to get a better understanding of conduction phenomena in polymers.