Space charge formation in glass materials after electron-beam irradiation

Charge distribution in various glass materials irradiated by electron beam was observed using PEA measurement system. Glass is used as a cover material for solar array panel of spacecraft. In space environment, the glass materials are sometimes charged up by irradiation of radioactive rays or plasma. The charging sometimes induced unexpected discharge accidents, which give serious damages to the spacecraft. Therefore, it is necessary to investigate the charge accumulation in glass materials irradiated by radioactive rays. In this experiment, we measured some kind of glasses with and without oxidized metal impurities. In the case of glass without impurity, almost no charge was observed after e-beam irradiation. On the other hand, negative or positive charge accumulations were observed in glass including oxidized metal impurities. The polarity of accumulated charge in samples irradiated by e-beam was related with the species of oxidized metal impurities.