Measuring system of internal charges in electron irradiated spacecraft's insulating medium

The accumulation of internal charge in the insulating medium caused by the high-energy charged particles has been one of the important factors threatening the safety of spacecrafts. As the spacecraft's orbital flight time and flight height increase, the internally charged effect of its insulating medium becomes more and more serious. In this work, we designed an internal charge distribution measuring system for an insulating medium under electron irradiation, based on the acoustic pulse method. The system could measure the internal charge of the dielectric material without contacting between the sample and the excitation unit. Furthermore, the internal charge measurements were performed on three kinds of typical spacecraft insulation medium materials (polyimide (PI), low-density polyethylene (LDPE), and polytetrafluoroethylene (PTFE)) under electron irradiation. The internal charge and internal electric field distribution of the specimens were obtained.