Characterization of the trapping of charges in polystyrene

Nowadays, many works are done to study phenomena occuring after the charges build up leading to breakdown. But few of them describe the behavior of insulator during electrons injection. In our work, abrupt electron ejections during and after the electron injection in polystyrene have been detected using a SEM by recording simultaneously the secondary electron emission current and the absorbed current. The observed ejection are explained by the reach of a critical field.